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INTERS – Interdisciplinary Encyclopedia of Religion and Science, edited by
G. Tanzella-Nitti, P. Larrey and A. Strumia, http://www.inters.org
Mind-Body Relationship
Gianfranco
Basti
I. Mind, Soul and Person:
Some Epistemological Observations 1 The Inadequacy of an Epistemological
Reduction of the Problem. 2. The Attempt of “Intensional” Logic: from
the Mind-Body Relationship to the Person-Body Relationship. 3.
Epistemological Characteristics of a Dual, Non-Dualistic Metaphysical
Approach. -
II. Metaphysical Theories of a Dualistic View. 1. The
Cartesian Theory. 2. The Theory proposed by John C. Eccles . - III. Theories of a
Monistic View. 1. Materialistic Monistic Theories. 2. A Special Kind of
Materialistic Monism: the Functionalist Theories. 3. Intrinsic Limitations
of the Functionalist Approach. - IV. Dual Theories of interpreting the Mind-Body
Relationship. 1. The Localization of the Mind. 2. Intentional
Theory of Knowledge. 3. The Mind is Immaterial and subsists “Post-Mortem”.
- V. Dual
Theory of the Mind and Spirituality of the Soul. 1. Immaterial Intellect
and the Brain. 2. The Soul as a Spiritual Substance that survives
after Death. -
VI. Cognitive Sciences and Dual Theory: Perspectives to understand the
Mind-Body Relationship. 1. Beyond the Darwinian Paradigm, and the
Development of Non-Darwinian Theories in Biology. 2. The Development
of Post - Functionalistic
Theories in the Cognitive Sciences. 3. Logic of Discovery vs. Logic of Proof .
The problem of the relationship between the mind and
the body, is one that has always fascinated humanity across all cultures
and in all times because of the many implications brought about by such an
issue, not least the religious and existential ones. At present the issue
is becoming more ample because of the progress of modern science and of its
capacity to comprehend, with its methods, the psychical functions, their
neural basis, their behavioural manifestations, and also the artificial
reproducibility, at least partial, of such manifestations and, at least in
perspective, the genetic modifiability of the neurophysiological basis of
the same psychical functions. Faced with these questions, however,
contemporary scholars are quite unprepared, because such progresses
continually put into discussion the “territorial” division operated by René
Descartes at the beginning of the Modern Age between the res cogitans, exclusive object of
philosophical-theological investigation, and the res extensa , object of the
physical-mathematical sciences. Starting from such a territorial division,
the modern religious conscience has often found in dualism — that is in
fact rooted in a tradition stemming form Plato to Augustine and to
Descartes — an apparently safe and simple way to overcome the many failures
emerging from the attempts to use science in order to explain human
self-consciousness. This way has been especially followed by a number of
scientists. However, the philosophical context of dualism leaves unsolved
those difficulties, that in the Middle Ages had already led the Magisterium
of the Church to find the vision of St. Thomas Aquinas to be more congenial
to the content of faith, a vision that we shall discuss here in this paper.
I. Mind, Soul and Person: Some
Epistemological Observations
1. The Inadequacy of an Epistemological
Reduction of the Problem. Before dealing with the main metaphysical theories of
the mind-body relationship that have followed on from each other throughout
the course of the history of Western thought, a logic and terminological
introduction, which involves profound theoretical problems, is necessary.
When pre-modern thinkers were dealing with such a relationship, they
generally would not refer to it with the expression “mind-body”, but rather
“soul-body”. The distinction between “mind” and “soul”, in these two uses,
is essentially that which exists, in contemporary terms, between a
“function” ( mind ) and the “structure” ( soul ) that exercises that function. Using the
language of classical metaphysics, it is the distinction between a
“faculty” — or “capacity to carry out (a) defined operation(s)”— and the
“entity” or “being” that owns that faculty as an “essential” property,
being typical or characteristic to it. In the Middle Ages, and especially
for Scholastic philosophy, the mens represented the source and the common root of
the two main faculties of the human rational  soul: intellect and will. In
this sense, the problem of the mind-body relationship is presented in a
double way: a) as a “psychological” problem of the relationship between the
so-called “superior” functions of the human psyche (intelligence and free
will) and the neurophysiological and physiological functions as such of the
human body; b) as a “metaphysical” problem of the relationship between the
subject of these superior faculties (the entity defined by classical
thinking as the “soul”) and the subject of the neurophysiological and
physiological functions (the entity, evident to everyone, that we define
“body”). Depending on whether these two entities become identified, or
distinguished, and also depending on the way in which they are
distinguished, we have varying metaphysical theories concerning the
mind-body relationship. However, when the problem is dealt with in terms of
the “mind-body” relationship, in many texts it is to be understood as being
restricted to the first of the two problems above (that is, to the psychological
one). Historically, this is due to the fact that, starting from David
Hume's (1711-1776) A Treatise of Human Nature (1740), modern thought, in
particular Anglo-Saxon authors, refer to the term mind as to the whole of the states
and/or the conscious functions of the human being, as opposed to the
Cartesian view of conscience as a substance in terms of a res cogitans , that is, an «individual
thinking substance of immaterial nature». As we know from the history of
philosophy, the notion of mind used by the English philosopher was totally
devoid of any ontological foundation, as was in general any other notion of
“substance”, whether material or immaterial.
The legitimate, scientific motivation of such a
reduction is linked to the epistemological posit typical of modern science that,
from Galilei (1564-1642) onwards, refuses to “try the essences” and,
from Newton (1642-1727) onwards, concentrates exclusively on the
“phenomenic”, that is on the observable as “measurable”. According to this
epistemological vision, that limits itself to study the observable
quantified and its laws, the reduction of our problem to the
psycho-physiological dimension alone, i.e. the analysis of the relationship
between the psychical and neurophysiological functions, is perfectly
legitimate. This reduction should be at least declared, so that it is clear
to those using such theories, and, above all, provided that other methods
of investigation on the same subject are not excluded ( REDUCTIONISM).
On the contrary a reduction that “in principle”
excludes the metaphysical dimension of the problem has to be judged an a
priori assessment. So does a vision that denies the mind-body relationship
as a relationship between two distinct “entities” (“the mental” and “the
physical”), reciprocally irreducible in such a way that the two disciplines
(psychology and neurophysiology) that have these two entities as their own
objects of study, are also seen as irreducible. When studying our problem,
one of the major conquests obtained in this century by logic and analytical
philosophy, has been the demonstration of the logic-linguistic
inconsistency of any epistemologically and linguistically reductionist
approach to the mind-body relationship (cf. Quine, 1987, p. 133). The
fundamental reason for the impossibility of this epistemological reduction
has been clear since the end of the past century, thanks to the work of
Franz Brentano (1838-1917). He rediscovered the irreducibly “intentional”
nature of each psychical act as such, opposed to the Kantian formalism in
the treatment of the states of conscience. The intrinsically
“directed-to-a-content” character of each psychical act, as a conscious
act, was rightly claimed against the Cartesian cogito and the subsequent Kantian Ich
denke überhaupt («I
just think»), that both wanted to treat the conscious thought as “pure
logic form” without any content. We do not “just think”, but, rather, we
always “think (perceive, want, etc.) something ”. The “subject-object”
relationship, that is the relationship between a “subject who intends” and
an “intended object”, is an essential component of all conscious psychical
acts, and for this reason it is defined as “intentional”. The logical
impossibility to identify “in principle” the “observational enunciations” of
the neurophysiological science with the “subjective enunciations” of an
individual, that describes our own psychical states associated with those
events observed by the neurophysiologist (as in the classical experiments
of psychophysiology), is due to the fact that these two languages follow
“two different and incommensurable logics”.
It is this incommensurability between physical and
psychical states that makes the position of the so-called “theorists of
identity” inconsistent (cf. Feigl, 1958, pp. 370-497; for a critical
outline, cf. Basti, 1991, pp. 76-85 and Moravia, 1996, pp. 5-38). The
theorists of identity hoped they could resolve the mind-body problem by
proposing a presumed “synonymy” between the two modes, the “psychical” and
the “neurophysiologic”, to denote the same object (the neural event), that
would imply the “ substitutivity ” of the one with the other. This
substitutivity, based on the identity of the reference used (that is on the
equivalence of the “extension” of the terms), is precisely what is
forbidden in an “intentional” logic. As a matter of fact, the “axiom of
extensionality”, which is implicit to the reasoning of the theorists of
identity, does not hold in the framework of an intentional logic. According
to such an axiom, two classes (or in a weaker form, two collections)
related to two distinct predicates that contain the same elements, in such
a way to make equivalent the extensions of the relative predicates,
represent the same class (or collection). From here it follows the reciprocal
substitutivity of the corresponding predicates. Closely connected to the
axiom of extensionality is the so-called “existential generalization”,
whose technical details we are not concerned with here. Such a procedure of
generalization, however, is disastrous for the logic of those types of
languages in which the axioms of “extensionality”, “existential
generalization”, and “substitutivity for equivalence”, clearly do not hold,
as happens, for example, in the language of poetry, where the terms cannot
be substituted with those of scientific language without compromising the
meaning and the expressive value of our propositions. All the types of
logic where the three axioms mentioned above do not hold, wholly or in
part, are called “intentional logics”. Synthetically, we could say that the
languages satisfying the rules of intentional logics are those where the
“ways” in which the terms describe (mean) their references —the
extra-linguistic objects to which they refer — and not simply the rough
fact of denoting them, become essential for the determination of the
meaning of the propositions of that language. According to this, we could
also say that a proposition constructed in an intentional form is
characterised by a double content: a) it is “connotative” (the intended
meaning) and, through this, b) it is “denotative” (the referring object).
2. The Attempt of “Intensional” Logic: from
the Mind-Body Relationship to the Person-Body Relationship. All the empiricist approaches
to the mind-body problem based on the epistemological reduction of the
intentional description of a psychical type to the observational
description of a neurophysiological type are therefore unproved, because
they suppose the substitutability of the two descriptive genres, as if both
followed an extensional logic. This groundlessness begins from the classic
Humean and Kantian theory of sensation defined as “pure impression” ( raw
feel ) in both
systems, considered as the psychical awareness of the mechanical
modification of the sense organ, thus supposing an identity between the
psychical modification of the mind and the mechanical modification of the
sense organ. The only theories of identity which are today
epistemologically acceptable — apart from their truthfulness, which is
another problem — are those so-called “substitutive of identity” theories.
Such theories are based on the assumption that, in order to build a really
scientific psychology, and according to the level of progress reached by
the neurophysiological and cognitive sciences in terms of supplying their
descriptions and explanations of given psychophysical phenomena, it is
allowed to operate, wherever possible, the following substitution. That is,
to substitute an intentional “subjective” description about the psychical event
with an “observational” description of the associated neurophysiological
events and, at the most, with the “cognitive” description on the processing
of information “implemented” in the aforesaid neurophysiological events.
The lawfulness of such substitution would depend simply on the fact that
each mathematical and experimental science, particularly according to its
modern meaning, is based on extensional-type logics. The intensional
logics, which are associated to the intentional reports of the psychical
events, are, at most, those of the ordinary language when the latter deals
with the mental events: those of a “ folk psychology ” and not of a “scientific
psychology”. This is Quine's position regarding the argument (cf. also
Churchland, 1986; Churchland and Sejnowski, 1992).
Obviously, there is no objection to the fact that
extensional and not intensional-type logics should be used in science.
However, could the extensional logics of science be considered apart from
the intensional component of each language, and in particular of the
natural languages? And, above all, to what extent can they do this at the
level of their foundations, particularly to formally resolve their semantic
problems, first of all that of reference and that of the necessity-universality
of their assertions? Were it impossible to think of an absolute
independence of the extensional logics from the intensional contents, as in
fact it appears to be, it becomes quite unlikely that where we talk about
“mind”, the producer of all languages and of their logics, we could imagine
a complete substitution, in the name of the extensionality of scientific
languages, the contents and the constructs of intensional languages. On the
other hand we comprehend how this irreducibility between the two reports of
the subject agent/perceiver that describes his or her own irreducibly
“private” psychical events — never to become completely objective even to
the subject that perceives them — and the external observer describing the
neurophysiological and informational (which are assumed to be) associated
in some way to those psychical states, would be justifying a further
epistemological approach to the mind-body relationship. Here we refer to
the approach of many authors, who declare that we should not literally talk
about the mind-body relationship, but rather of the “subject-body” or even
of the “person-body” one.
This position has acquired importance thanks to the
analysis of one of the best known representatives of analytical philosophy,
Peter F. Strawson (b. 1919), who, moving against Descartes' position, and
in full harmony with the epistemology of Scholastic philosophy, considered
the “person” and not the “mind” as the characteristic subject of
intentional language. Moreover — and in accordance with the Scholastic
philosophy — Strawson considered the “person” as a primary notion, no
further reducible to any other notion (cf. Strawson, 1959; similar
positions, though with minor differences, more or less emphasized, were
also put forward by Wilkerson, 1974; Greene, 1976, pp. 113-129;
Margolis, 1978; Nagel, 1979; Dreyfus and Hall, 1982; for a review on these
approaches to the mind-body problem cf. Moravia, 1996, pp. 233-266).
From a logical and epistemological standpoint, to establish that the problem
we are dealing with is not “mind-body”, but more properly “person-body”, is
not a trivial assertion, considering not only what we have already said
regarding the point of view of the subject of the intentional acts and of
his or her absolute individuality, but also considering the complementary
point of view given by the analysis of his or her corporeal properties, as
it had been already noticed by Moritz Schlick (1882-1936). The “own” body
as seen from the subject —“ my body”— never coincides with the body observed by an
external observer, given that the “own” body is the body that by definition
can never become completely objective to the personal subject that owns it
(cf. M. Schlick, Meaning and verification in “Tra realismo e
neopositivismo”, edited by L. Geymonat, Bologna 1974,
pp. 187-218).
3. Epistemological Characteristics of a Dual,
Non-Dualistic Metaphysical Approach. To conclude this section, we observe that all of
the cited authors —and I include also myself together with them— invite us
not to metaphysically overrate the logical-epistemological approach of the
anti-reductionistic type as it is here put forward. The “duality” of
“mental” and “physical” languages, and the irreducibility of their
references, do not imply the “dualism” of the substances of “mind” and
“body”. It is not by chance that none of these authors agrees with a
“dualistic” Cartesian solution to the metaphysical problem that emerges
from this analysis. On the other hand, we do not agree with those authors,
such as Quine, who state that the mind-body problem, if correctly set upon
these non-reductionist epistemological bases, should be exclusively a
logical-epistemological one, and not also a metaphysical problem. Such a
position implies a wrong epistemological conception of metaphysics, one
typical of the Modern Age ( METAPHYSICS, II-III). In a few words, to state that
metaphysics is the “science of the being ( ens ) as such”, does not mean that
metaphysics is the “science of the being ( ens ) as existent ( existens )”. The fact of reducing being
to the dimension of existing alone and of its factuality is, once again,
the result of an “extensionalist” reduction of the notion of being, brought
into modern metaphysics by the “competition” between modern
physical-mathematical sciences and their extensional languages. The “being”
described in metaphysics is not only the “extensivity of being” ( existentia
), the “being”
of the referent of a true affirmative proposition, or of the “non-being” of
the referent of a true negative proposition. The being of metaphysics is
also the “intensivity of the entity” ( entitas ), of the “being as” (“as a
horse”, “as a man”, “as a number”, “as an atom”, “as a substance”, “as an
accident”, etc.), respect to certain properties, which are “essential” for
an adequate description of a referent in a given and limited context, and
without which it would make it impossible to build any positive proposition
on it.
It was thanks to Thomas Aquinas (1225-1274) and
to the contemporary reading of his doctrine of the “being as act”, as an
“intensive” esse , worked out by Cornelio Fabro (1911-1996), that this issue was
given particular attention in the neo-Scholastic philosophy of the 20th
century (cf. C. Fabro, Partecipazione e causalità , Torino, 1961). In other
words, when we say about a certain being x that “it is an entity”, or “it
has being ”,
we are not merely saying that “it exists”. Rather, we cannot satisfactorily
answer the question “does it exist ?” if in first place we have not
sufficiently answered the question “what is that being that should exist
?”. The term “being” which is next to the term “is” ( copula ) in the scheme “ x is a being” does not primarily
indicate the existence of that being, but rather the entity of that being,
that set of properties which are necessary, though never sufficient, to
determine that being. When captured in a (always) partial manner by a
defining-type proposition that refers to a subject as a general term
denoting a collection of beings, such “essential” properties endow that
same proposition with a subject-predicate reversibility (i.e., “man is a
rational animal” as an equivalent to “the rational animal is man”) that
grounds its analyticity of non tautological nature in a given linguistic
context, and grounds as well the logical necessity of that proposition and
of the propositions correctly deducible from it. That is why we were not,
and neither we intend to be, dualistic when, according to the initial
linguistic analysis, we stated that it was correct to talk about the
“mental” and the “physical” as two distinct entities, without at all
implying that through this statement we were admitting (or denying) the
existence of two distinct beings relatively to these “entities” and to
their semantic fields. These “two” distinct and irreducible entities
figured as a closed polygonal line and the surface that it includes, can be
very well two components of a unique “existing” psycho-physical being, the
human person. This is logical-epistemological nucleus of the “dual”
metaphysical theories — neither “monistic”, nor “dualistic”— of the
mind-body relationship. We hold that these are the theories that provide
the most adequate (true) metaphysical solution to our problem, besides
representing the solution that is most consistent with the Christian faith
on the (temporary) immortality of the soul, and on the (definitive)
immortality of our person risen from the dead, reconstituted in its
psychophysical unity (RESURRECTION, IV-V).
II. Metaphysical Theories of a Dualistic
View
The mind-body problem was first introduced by Plato
(427-347 B.C.), the principal representative of the dualistic theory.
According to his theory the soul and the body constituted two separate
substances that interacted causally, and the soul represented the “driving
force of the body”. The soul moves itself, and at the same time it moves
the body that is seen in this way as a “tool” of the soul, according to the
famous metaphor of the helmsman and of the ship (cf. Republic, IV, 438d-440a; Timaeus, 42e-44e; 69c-77c; 89d-90d; Laws
, X,
894e-898d; however, this metaphor precedes Plato). In the Modern Age the
dualistic theory was once again put forward in the 17th century by
Descartes, and in the 20th century by Eccles.
1. The Cartesian Theory. Unlike Plato, René Descartes
(1569-1650) considers the organic body of living organisms, including the
human body, as an “automaton” of inertial type. It is an automaton in the
sense that it does not need any finalistic principle for the explanation of
its functioning; it is “inertial” because it is based on the determinism of
the principle of inertia. The two most fundamental dilemmas of the
Cartesian dualistic theory are the “logical-metaphysical” and the
“physical-mathematical” problems.
a) From the “logical-metaphysical” point of view
Descartes demonstrates the existence of an individual spiritual substance
based on the cogito , using the ancient Augustinian proof the wrong way ( DESCARTES,
IV). The French philosopher claimed that from such a demonstration he would
derive self-evident information not only on the “existence” of a
conscience, but also on its “nature”. As already noticed by his
contemporary Gassendi, and after him by Kant, Hegel and Husserl, the
Cartesian claim of saying that «I think therefore I am, such that there is
a thinking object ( res cogitans )» is equivalent to saying that «I think therefore I
am, i.e. there is a “thinking individual spiritual substance”» has
absolutely no foundation. The cogito proves up to a certain extent the existence of a
conscience although the nature of this conscience, whether material or
spiritual, individual or meta-individual, is another issue. In relation to
this, Aquinas, commenting upon Augustine, stated that the
introspection given by the cogito only proves the existence of a psychical life
within us. However in order to decide which nature this psychical life is,
whether it be material or spiritual, individual or meta-individual, a subtilis
et difficillima inquisitio is required — as the Averroistic Aristotelians declared
at the time of Aquinas (cf. Thomas Aquinas, De Veritate , q. 10, a . 8, where this
«subtle and extremely difficult research» is brought forward in a synthetic
form and with exceptional clarity and depth).
b) From the “physical-mathematical” point of
view, the establishment at the time of Plato of an interactionist doctrine
that viewed the soul as the subject of a special action on the vapor
particles (air + water + heat) of the so-called “corporeal spirits” of
ancient neurophysiology, found no problem. From ancient Egypt and from the
book of Genesis up to the time of Luigi Galvani (1737-1798), the interactionist
doctrine attributed the transmission of the nervous impulse (whose electric
nature was discovered by Galvani) to a sort of fluid along the nerves,
reduced to microscopic capillaries. This, however, could not hold for the
physical-mathematical explanation of inertial type, which Descartes
proposed in his physiology for the action of corporeal spirits. The idea
that the spiritual soul would shift the direction of motion of a flow of
“spirits” in the pineal gland (epiphysis) of the brain, in such a way to
set off a “voluntary” movement of the human body, was against a fundamental
principle of conservation in mechanics, directly derived from that of
inertia, known as the “principle of conservation of momentum”. Therefore, a
non-extensive substance such as the Cartesian res cogitans cannot minimally deviate the
motion of anything endowed with a mass, no matter how little it is. In any
case, moving beyond any specific criticism to the Cartesian mechanism,
every dualist-interactionist theory between spiritual minds and material
bodies implies a violation of some kind of principle of energy
conservation. In this way, such a criticism completes from a modern
scientific point of view the criticism that in the Middle Ages St. Thomas
had already made against Platonic interactionism in metaphysical and
theological terms ( SOUL, V.2). As a matter of fact, while criticizing
Platonic dualism, Thomas Aquinas affirmed that if the spiritual soul is in
a causal relationship with the body through the influence on the action of
the corporeal spirits, then the principle of the substantial unity of the
person is lost, and it becomes difficult to explain the individuality of
the soul, which according to Plato can reincarnate in different bodies, a
hypothesis which is considered absurd by Christian theology (cf. Thomas
Aquinas, Summa Theologiae , I, q. 75, a. 7, ad 2um ;
q. 76, a. 7 corpus and ad 2um).
2. The Theory proposed by John C. Eccles . The most fundamental
contribution that John Eccles (1903-1997) made was the attempt to provide a
new solution to the physical-mathematical problem of the violation of the
conservation principles that emerges in all interactionist approaches; like
many other modern authors, he was convinced that the only way to support
the right ethical and religious reasons for the existence of a spiritual
soul was to adhere to a dualist-interactionist metaphysical vision of a
Platonic-Cartesian type (cf. Eccles and Popper, 1977; Eccles and Robinson,
1984). Eccles believed to have found such a solution through the reference
to the principles of quantum mechanics, necessarily involved in the
chemical-electrical mechanism of synapse communication. In fact, according
to the principle of indetermination, we could think of an extra-physical
action exerted by the mind on the synapses of the various cortical neuronal
populations, without the violation of any principle of energy conservation.
There are two main objections that can be moved towards this solution, one
of a biological type, and the other, more substantial, of a physical type,
they both having immediate metaphysical implications.
a) From a biological point of view the fact of
claiming that the characteristic level of the psycho-physiological
phenomena corresponds to the microscopic scale of the quantum interactions
between the molecular components (proteins) of the nervous cells, makes
Eccles' theory subject to a physicalist reductionism. Generally speaking,
most biologists agree in saying that the characteristic physical level
where the vital phenomena emerge in their irreducible specificity is that
of the macroscopic scale, where the organization and possibly the
self-organization of complex molecular structures (proteins) occur, which
are stable out of the thermodynamic equilibrium. They are “dissipative
structures” that self-organize and continually exchange matter-energy with
the external environment, internally and externally to the body (cf.
I. Prigogine, From Being to Becoming. Time and Complexity in the
Physical Sciences ,
San Francisco 1980; I. Prigogine and I. Stengers, Order Out of
Chaos. Man's new Dialogue with Nature , London 1984; I. Prigogine, Exploring
Complexity. An Introduction , New York 1989). Yet, here we are faced with an
important metaphysical consequence. If we accept that the biological and —
in our case—the neurophysiological level is that of the microscopic quantum
scale, given that such a level and its related uncertainty are universal
for all the material structures of organic and non-organic nature, why then
not brush up again the Gnostic and Neo-Platonic theories of the anima
mundi type?
Then, why would not all matter be animated? This is what, in fact, was
suggested in the years 1960-1970 by a few theosophical movements — some
very prestigious due to the known scientific personalities involved, such
as the so-called “Gnosis of Princeton”— that were actually based on such
principles ( NEW AGE, III-IV; PANTHEISM, III.1).
b) Much more substantial is the “physical”
objection against interactionism, which is supported by authors like Roger
Penrose who, although coming from a non-dualistic standpoint, is among the
supporters of the role of quantum phenomena in the study of the physical
basis of conscience. His objection is that it is unfounded to endorse the
suspension of the causal physical determinism on the account of the quantum
uncertainty (DETERMINISM/INDETERMINISM, II.3). The quantum phenomena
only show uncertainty when faced with the problem of “reduction of wave
function” and to the problem of the amplified “reading” of quantum event,
on a macroscopic scale, in terms of the mathematical formalism of classical
mechanics (that is, in terms of the functions that define one-dimensional
trajectories; cf. Penrose, 1995, p. 349). On the other hand, the
description of quantum phenomena (in the microscopic terms of the
appropriate mathematical formalism of the wave function) is supported by
experimental measures which agree with the theoretical predictions, and
show no uncertainty at all, despite the temporary state of quantum
electrodynamics which provides such predictions (cf. R. Feynman, QED.
The Strange Theory of Light and Matter , Princeton 1985). Therefore, it is not at the
quantum level that we can hope to solve the scientific groundlessness found
by modern authors in the dualist interactionist explanation.
III. Theories of a Monistic View
Theories of a monistic view are “metaphysically
reductionist”, and they still are even at present time, when they are
forced to be “epistemologically non-reductionist” by logical evidence (see
above , I).
These are metaphysically reductionist since they reduce one of the two
terms to the “product” of a function (or many functions) of the other. The
history of philosophy of the second millennium brings to us two distinct
types of monistic theories, spiritualist and materialist. The former can be
essentially reduced to a single theory of this type, that Leibniz
(1646-1716) presented in his Monadology. According to this theory, the
body results as a “representation” of the spirit. This philosophy of nature
considers the material particle in terms of an “non-extensive singularity”,
hence immaterial, of a “monad”, in such a way that each physical body
results as an aggregate of immaterial monads, all which are in the end
“internal” representations of the Absolute Monad. This theory, that was
judged by Hegel as a “metaphysical novel”, for us it is merely of academic
interest. Here we shall dedicate more attention to the theories of
materialist nature.
1. Materialistic Monistic Theories . The materialistic monism consists
in the reduction of human psychical life to the product of the
neurophysiological functions of the body, considered a sort of “secretion”
of the neurons. As main representatives of this anthropological teaching we
can consider all the major empiricist philosophers of the Modern Age, from
Hume to the contemporary positivists and neo-positivists. In the 20th
century, this way of proceeding is presented in different versions ( SOUL, VII.2).
A first version is that of the “theories of identity”,
already presented in Section I and which we do not need to recall again. A
second version is represented by the “emergentist theories”. The
emergentism is highly popular amongst the neurophysiologists and those who
have a background education in the natural sciences, such as physics,
chemistry or biology (cf. Bunge, 1980). The term “emergence” is to be
understood at a level of organization of matter that, maintaining the
validity of the laws at the lower level, needs for its scientific
characterisation the formulation of new laws. For example, it is evident
that the laws of thermodynamics apply to all chemical systems, however it
is not possible to simply derive from the laws of thermodynamics all of the
chemical properties of the molecular compounds, although it is clear that
in both cases the referent is always the same aggregate of molecules ( CHEMISTRY,
IV). With the same type of reasoning the theory attempts to explain the
emergence of the psychological facts and their laws as the emergence of a
new, higher level of organization of the same physical substratum. Here, we
are not far from a theory of identity: moreover, there are always
emergentist signs in all theories of identity, from that of Feigl to that,
more recent, of Patricia Smith Churchland. The limits of the identity
theories already discussed, are the same as those of the emergentist
theories.
A third version of materialistic monism is represented
by the “behaviorist theories”. Behaviorism started off in the 1930's as a
particular school of empirical psychology, with the works of John
B. Watson (1878-1958), and considered each reference to the 18th
century psychology of conscience as non-scientific, in particular that of
phenomenological nature. Then the behaviorist theory acquired philosophic
dignity in the 1950's, thanks to a fundamental work by Gilbert Ryle
(1900-1976), The Concept of Mind (1949). The leading idea of this theory is the
non-objectivable character of the conscious “self”, intended as the
“presence to my self” (what I am able to render as an object to myself is
only “me”, however always relatively to its past states or acts) and its
systematic elusivity, like the present temporal moment, the “now”, the nunc
. From that it
derives its criticism to the “Cartesian self”, intended in an objectivistic
way as a “spiritual thing”, and the proposal of a “dispositional
behaviourism” as the characteristic object of a really scientific
psychology. In other words, because of the systematic elusivity of the
temporal moment, what is objectivable of behaviour is not the physiological
event as such (for ex. the modification of the physical state of a
population of neurons), but rather the modification of the “disposition to
act” of a number of organs (for ex. the modification of the electrical
action potential of an aggregate of interconnected neurons). This approach
has resulted particularly prolific in scientific terms because it created
on a theoretical scale a link between the old type of behaviourism
belonging to the associationistic psychology of Pavlov and Watson and the
computational approach typical of functionalism, and this because the
notion of a “disposition to act” correspond immediately to the matrix
calculus of statistical mechanics applied to the study of the cerebral
dynamics. In fact, a status that shows disposition to act can find its
immediate operational equivalent in a matrix of transition probabilities,
which is, in statistical mechanics, a classic algebraic instrument of
calculus. Such a matrix of n ∞ n elements, for each time tk , defines for each element the
probability of transition from one to any other of its possible states (for
ex. the probability for each neuron in a network of interconnected neurons
to jump from an active to a non-active state, and vice-versa) in a manner that
is conditioned by the state of the other elements in the matrix. On a
formal scale the “neural networks” are nothing more than very evolved, and
sometimes very complex, versions of this basic idea ( INTELLIGENCE,
ARTIFICIAL, II.6).
2. A Special Kind of Materialistic Monism: the
Functionalist Theories. At the beginning of the 1960's Hilary Putnam (born in 1926), with
his famous work Minds and Machines (1960), launched the research program of
“functionalism”, having the intention to solve the mind-body problem in
terms of the software-hardware relationship of a computer. Such an approach, which is
today completely repudiated by its initiator, had the intention to
re-propose on a new basis the classical rationalist theory of the mind.
Putnam did so in the light of the notion of “cognitive unconscious” taken
from the psychology of intelligence elaborated by the Swiss psychologist
Jean Piaget (1896-1980), who identified the intelligence with the
development of logical-formal operational schemes and their unconscious use
by the subject (cf. J. Piaget, Logic and Psychology , 1930; J. Piaget and
B. Inhelder, The Early Growth of Logic in the Child , 1960). Putnam's second pillar
was the development of a theory of computability starting from the
mathematical interpretation of formal logic and the notion of propositional
function operated by Gottlob Frege (1848-1925), which had experienced two
futher steps. First of all, between the 1920 and the 1930, we had the
invention and the development of the lambda- calculus, through which the
great American logical-mathematician Alonzo Church (1903-1995) demonstrated
that all computable functions of the logic and/or mathematical calculus are
also algorithmically computable through “recursive” functions. Secondly,
the English mathematician Alan Mathison Turing (1912-1954), who is the
father of modern computers, discovered in 1937 an elementary scheme for an
algorithmic machine, the “Turing Machine” (TM), which was able to calculate
any recursive function and/or to simulate the calculations performed by
another TM, until the construction of the “Universal Turing Machine” (UTM),
able to simulate the calculations of any other TM. Therefore, the UTM
constitutes the logical scheme of a modern multi-programmable calculator.
The link with the field of behaviourism was derived by a further
demonstration obtained by W.S. McCulloch and W. Pitt in 1943,
that guaranteed the equivalence between the algebraic matrix calculation of
a simply interconnected network of neurons and the calculations which were
executable by a TM. From here followed, in the 1950's, the development of
the two main features of functionalism, that ultimately led to the
so-called “strong version” of the research programme of Artificial
Intelligence (AI): the idea of artificially simulating the intelligent
human behaviour, and the idea of an essential isomorphism (biunivocal
correspondence) that must formally exist between a logical calculation
performed by the brain of a human being that is performing a certain
intelligent behaviour and the software that “runs” (that is, the
formal calculation executed on symbols) on a computer that is able to simulate that
behaviour (cf. Turing, 1950, pp. 433-460).
In spite of the extreme theoretical interest and its
scientific inventiveness —that made possible the birth from a functionalist
research program of a new discipline linking together psychology and
neurophysiology in the new field of “cognitive sciences”— the most
fundamental limit of this approach is the purely formal, exclusively
extensional, character of the logical calculations which can be simulated
by a TM (
INTELLIGENCE, ARTIFICIAL, IV). It appears therefore totally insufficient in
accounting for the intentionality and the intensional logic referring to
the “contents” (cf. Searle, 1980, pp. 128-135 and Searle, 1983), and
results also deprived of the fundamental “Socratic” property of human
intelligence, that of the “knowing of not knowing”, and thus of the ability
to judge the truth and the consistency of those theories and ideas which
are produced by it. An incapacity which is formally linked to the theorems
of incompleteness of Kurt Gödel (1906-1978) on the limits of a purely
formal metalogic ( GÖDEL, III-IV; LOGIC, IV) and that is usually identified
by the AI theorists with the systematic incapacity where the machine is
concerned, unlike the mind, to “take the distances” from the task being
executed in order to judge it “from the outside”. For this reason, in the functionalist
approach of “strong” AI, it is necessary to rely on an “oracle”, according
to the expression coined by Turing himself, a figure of unquestionable
universal intelligence that is able to produce its responses of truth and
coherence without conceding any possible control on its action. Hofstadter
(1979) comes to this conclusion and ascribes in a neo-Spinozian way the
metalogic function of “universal intelligence”, of “oracle”, to the
non-computable determinism of the matter as a whole, matter of which also
the brain of a single individual is part of, a determinism that appears
“inviolable” towards the necessarily partial self-referentiality of the
cerebral computations of a single brain. In such a way, functionalism
reveals its “double monist” nature for a theory of mind-body relationship.
It is monist not only because it denies the “immaterial” dimension of
intelligence, but also, and above all, because it denies the existence of
“individual” intelligences which produce thoughts and are capable to act
freely. That is, it denies the metaphysical foundations of the notion of
person. From a metaphysical point of view, functionalism appears as a
re-proposal of the rationalist theories of the mind that deny to the single
individual the capacity to think “with his or her own head”, as was
proposed already in the Middle Ages by the theories of the Arabian
rationalist aristotelism of Avicenna and Averroes, in the Modern Age by the
theories of Spinoza and Hegel, and in the contemporary ages by the doctrine
of Husserl and his meta-individual “phenomenologic Self”.
3. Intrinsic Limitations of the Functionalist
Approach . On
the other hand the approach of the cognitive sciences to the study of the
mind and of the mind-body relationship can also be interpreted according to
a “dual” type of metaphysical scheme, provided a renunciation of its
original functionalist character. However, before examining the dual
theories, it is necessary to make a brief consideration about the intrinsic
limitations of the functionalist approach, or theory of the “strong” AI ,
that leads its authors to the “oracle solution” and brings them to the
above mentioned twofold monist outcome. It is clear that in the
functionalist approach each human mind corresponds to a UTM, given the
capacity the human mind has for a universal thought. Now, the incapacity of
a UTM “to have the knowledge of not knowing” depends upon the famous
theorem of limitation which is intrinsic to the Universal Turing Machine
computations. This machine has the capacity to simulate the calculations of
all the single TM, in such a way to confer universality to their
computations, but has the limitation of not being able to decide when its
calculations have reached a satisfactory outcome and have to stop
consequently. In particular, the UTM cannot find a decisive computational
procedure, through which “to assert” in its (arithmetic) meta-language that
a certain datum expressed in its (arithmetic) language is “false”. For this
reason, it is said metaphorically that the UTM “cannot have the knowledge
of not knowing”. Yet, this is exactly where human intelligence begins.
Human intelligence is capable of correcting itself, of progress and
development, unlike animal intelligence, precisely because of its ability
to notice its own errors. The incapacity of a formal calculation to decide
upon its own falsity depends upon the theorems of incompleteness of Gödel
regarding axiomatic arithmetics, and particularly upon the second theorem
of incompleteness ( GÖDEL, III), that excludes the possibility of formal
arithmetics being its own meta-language (on the theories of limitation of
the UTM, see the introduction by Penrose, 1995, ch. 3; for the
interpretation of the limits of the UTM as a denial of the Socratic roots
of human intelligence, cf. Basti and Perrone, 1999, pp. 553-566). From a
point of view that takes into account the history of logic, to overcome the
mentioned limits of the formal calculus would mean, at the same time,
overcoming the limits of the axiomatic method itself, as if it were the
“only” method in modern logic, and to recover the richness of the
pre-modern analytical method, characteristic of Platonic, Aristotelian and
Scholastic logic: the logic of induction, abstraction and analogy. In a
word, to perform these operations would mean to render scientific dignity
to the “logic of discovery” against the modern absolutism of the “logic of
proof” and of its axiomatic method (cf. Cellucci, 1998).
IV. Dual Theories of interpreting
the Mind-Body Relationship
When speaking of “dual” theories we mean all those
theories of the mind-body relationship that: a) against materialistic
monism, and like the dualist theories, admit a reciprocal irreducibility of
the “mental” as a product of a function, or an ensemble of functions, of
the body; b) against dualism, they support the psychophysical unity of
the living organism and, in our case, of the human being.
In such way the mind-body relationship is interpreted
according to the Aristotelian “hylemorphic” metaphysical scheme of the
form-matter relationship (gr. hyle, matter, and morphé, form; MATTER, II.3). According
to the version given by Scholastic anthropology, the spiritual soul is the
form of matter, and “form” and “matter”, substantially united, constitute
the living human body, the only personal substance of a human being and of
that “unique” human being, capable of vital vegetative operations
(metabolism, growth, reproduction), and of sensory-motor and intellectual
functions (for a review on the principles of the Aristotelian-Thomistic
biology, cf. Basti, 1995, pp. 131f). With respect to the monist and
dualist theories, the “dual” theories have three main characteristics: the
first one regards the “localization” of the mind with respect to the body;
the second regards the “non-representational epistemology” associated with
it; finally, the third one regards an original solution put forward for the
problem of “immateriality” and of post-mortem “subsistence” of the soul
separated from matter. These characteristics (especially the third) are
strongly present in the medieval thought of Thomas Aquinas, who made the
choice to re-evaluate the Aristotelian hylemorphic approach in anthropology
—not without operating a profound revision of its metaphysical basis. He
noticed that, besides an intrinsic superior coherence, such an approach
could grant a great consistency with the principles of Christian
anthropology, more than that shown by the Platonic dualist approach,
especially for what concerned the person, its irreducible individuality and
its intrinsic psychophysical unity ( SOUL, III and V). Many contemporary
authors who operate today in the field of cognitive sciences intend to
refer to a dual-type, and not to a monist-type metaphysical paradigm, even
though only a few of them, in the recent past, were clearly aware that such
metaphysical paradigm was not compatible with the functionalist approach of
the cognitive sciences (cf. for ex., Fodor, 1981, see below , V).
1. The localization of the Mind. The mind (or, in the
Scholastic, Greek-Platonic terminology, the “soul”) is indeed a
non-material “thing”, as Descartes would have liked, however it is not a
“substance” that is complete in its being in the way it is stated by the
dualist theories. It is the formal principle of unity of a stratified whole
of material parts (today we would say: atoms, molecules, proteins, cells,
tissues, organs) such as the living human body, a principle that enables
this whole capable of performing certain operations, at the most those
voluntary and intellectual of a personal human subject. It is rather a
non-material or “formal” component of a substance made of material parts
that experience constant modification. Where the notion of “form” is
understood according to the Aristotelian philosophy of nature, as a
constantly adapting plastic whole of relationships of disposition of
dynamic material parts, continually modifying and interacting among
themselves and with the external world. An example of it, is given, at the
cellular level, by the metabolic physical-chemical activity of the cell
itself. In this context the “mind”, according to the dual theories, has a
unique location with respect to the body, which the mind itself organizes.
Instead of being located “in the body” and at the most “in the head”, as in
all of the dualist theories (Plato assigned its location to the attachment
point of the neural cord with the cerebellum, Descartes in the “pineal
gland” (epiphysis), Eccles in the synapses of the populations of neurons in
the cerebral cortex), and in the ancient and modern monist theories, an
illustrative solution that M. Schlick defined “principle of
introjection”, the dual theories rather affirm that “it is the mind that contains
the body”. The
mind is in fact considered as a formal whole of relationships of
organization (communication and control) between material parts undergoing
a process, in constant physical-chemical interaction, that grants to such a
dynamic whole a unity, identity and specificity in time, which are
themselves also plastic, dynamic, in constant modification of adaptation to
an environment that changes. In a book which is strongly and justly
critical towards the functionalist approach to the cognitive sciences,
Penrose expresses himself on the matter: «Most of the material of our
bodies and brains, after all, is being continuously replaced, and it is
just its pattern that persists [...]. It is not all unreasonable to suppose that
the persistence of the “self” might have more to do with the preservation
of patterns than
of actual material particles» (Penrose, 1995, pp. 13-14). Here is
instead what was stated on the same argument by Donald M. MacKay
(1910-1986), one of the founders of the non-functionalistic approach to the
cognitive sciences, to whom, amongst other things, we must acknowledge the
definition of “dual theories” applied to this particular type of theories
of the mind: «In the first place, it meant that although looking for “the
seat of the mind” was not meaningless, it was not something to be achieved
by analysis of the brain into components and looking for “action of the
mind” on individual parts. Mental activity would be meaningfully locatable
(in principle) in specific flow-structures of the information-diagram; but
this meant that the relevant flow-lines would in general extend beyond the
confines of any one component structure, and during conscious action might
even run out-and-back through the environment. Mentality, as a
system-property, could be rendered invisible or destroyed by attempts to
localize its action to any subsystem of the total information-flow pattern
in which it was currently embodied» (MacKay, 1980, p. 1389). More
recently, the same idea that the mind is embodied within the informational
flow schemes, internal and external to the body, received support from
A. Clark (1997). It stands as the new post-functionalist paradigm in
the cognitive sciences, one that tries to unite different elements, albeit
not without some confusion. Among them are: the traits of the phenomenology
of corporeal qualities of Heidegger and Merlau-Ponty; the
non-representational theories of the mental activities which are typical of
robotics, of the connectionist approach to the neural networks and of the
“ecological” approach to perception of J.J. Gibson; the theories of complexity
used in the study of the non-linear dynamical systems.
Regarding the localization of the mind or of the
“rational soul” of the human being with respect to its body, in the Middle
Ages, Thomas Aquinas held a position that was very similar to that of the
modern supporters of the dual theory. He said precisely that non-material
entities, such as the soul, can be localized with respect to the matter
that they control and organize, not through a relationship of contact
between the external surfaces of a body “that contains” and those of one
that is “contained”, as it takes place between material entities.
Non-material entities, rather, must be localized through «the extension of
the capacity to control and organize (lat. gubernare et regere ) matter» that, thanks to this
global control and organization, constitute a living body, an “organism”
with specific faculties. For Aquinas the attempt to localize the soul and
its action in specific parts of the brain, such as that brought forward at
his times by the interactionism of the Platonists, is totally wrong and
misleading (cf. Summa Theologiae , I, q. 52, a. 1; q. 76, a. 8).
Resorting to this same principle, he justified the omnipresence of God in
the universe, for His actual capacity to govern everything (and not just a
body as in the case of the human soul in each one of us). According to St.
Thomas, only in this way does it make sense to say that the whole universe
«is in God»,
as it is stated by the Holy Scriptures and theology (for an historical
overview, cf. Basti, 1991, pp. 266f ).
2. Intentional Theory of Knowledge. A second characteristic of the
dual metaphysical theory of the mind, immediately linked to the original
localization of the mind with respect to the body in the theory itself, is
that it appears connected to an “intentional” theory of knowledge, as much
as the other two types of theories are, at least in modern times, dependent
upon an exclusively “representational” theory (representationism) of
knowledge. How the history of modern philosophy teaches us, the emergence
of a representational theory of knowledge is nothing more than the
epistemological counterpart of the progressive establishment of the
absolutization of the axiomatic method in modern mathematics and logic ( LOGIC, III),
that identifies in the theory of demonstration and proof the only object of
logic as science and as organon of the mathematical and natural sciences. So much the
questioning about the truth and the foundation of axioms is well far beyond
the interest and the capacity of the axiomatic method, how much, in a
similar way, does the questioning about the “thinking thought” (the intellectus
for the
thinkers of the medieval period) that formulates ideas and produces logical
symbols in a truthful relationship with the object, with respect to the
representational theory of knowledge. A questioning, that on the thinking
thought, which limits itself just to the analysis of the “thought which is
thought”, the thought that manipulates symbols which are already
constituted according to logical and formal rules (the ratio in medieval terms). This got to
a point in the 19th century when a project was conceived to reduce
epistemology and logic to a unique “universal algebra” of thought, reduced
to a pure syntactic formalism occupied with the manipulation of graphical
“signs”, no longer without a symbolic (semantic) value. The building of a
TM is probably the higher expression of the formalist approach to logic and
epistemology, but for this very reason it indicates, at the same time, the
beginning of an unstoppable decline. The intrinsic limitations of the UTM
(see above , III.3)
have revealed the relevance of the logical-foundational questions over the
calculus and its automation, the latter being the major contribution given
by the modern scientific revolution from Newton and Leibniz onwards. It is
certainly not due to mere chance that the principle of intentionality came
to acquire an ever greater relevance in the contemporary epistemological
and logical-foundational debate, as it became increasingly evident that
there was on the one hand a failure in the formalist approach to the
foundations of logics and mathematics, and, on the other, the insufficiency
of the functionalist interpretation in the cognitive sciences.
3. The Mind is Immaterial and subsists
“Post-Mortem”. In
the 13th century, when Thomas Aquinas had to face these problems as a
philosopher and a theologian, he was in a very similar situation to ours.
On the one hand, he had a traditionalist theology and philosophy of
Platonic kind, which were linked to a fading spiritualism; on the other
hand, he had the Aristotelian philosophy, which was linked to the culture
of the new universities, and whose theory of the soul as a form
of the body made the justification of the immortality of the soul
problematic, especially when intended as immortality of the individual
being. In a particular way, in the last part of his life, Aquinas, in
Paris, had to face up to that “lay” interpretation of the Latin Averroism
of Siger of Brabant (1235 ca. -1282) who, on the one hand interpreted
in a materialistic sense the mind of the single individual, and on the
other hand supported the theory of a single “universal intellect”,
meta-individual, with the purpose of assuring a universality to the
products of the logical thinking. As an answer to these theories Aquinas
proposed his own interpretation of the Aristotelian rational soul as form
of the body ( SOUL, V.2). In so doing, he wished to obtain two main
results: a) to assure spirituality or immateriality to the rational
faculties of the mind, in order to justify the capacity of universal
thought of the single individual, and its freedom of action (in such a way,
though, to explain that a cerebral accident could totally or partially
prevent the practice of these faculties); b) to solve the apparent
antinomy of a soul that on a metaphysical scale is a form of the matter of
a body, hence which determines the “single substance” of the human person,
and at the same time must be able to subsist on its own as an individual
(and not as a group entity) after death, being in some way “itself a
substance”.
V. Dual Theory of the Mind and Spirituality
of the Soul
1. Immaterial Intellect and the Brain. As far as the first problem is
concerned, that is how to ensure the immateriality of the intellectual
faculties, the solution proposed by Aquinas is similar to that which is
proposed today by the functionalist theory. The latter, in order to justify
why the human being has the capacity of rational thought, particularly the
“creative” capacities, hypothesize the existence, “outside” of the system,
of a “closure” of the hierarchy of partially self-referential controls that
characterizes the living body. However, instead of identifying such
“closure” with the “unique” intellect of the Averroists —and/or with the
“oracle” of the non-computable determinsm of matter that comprehends also
the single human body, as modern functionalists did— Thomas Aquinas
identifies it with the individual intellectual faculty of each human being;
and especially with that area which produces concepts, that is, with the
“thinking thought” or the “agent intellect” as traditional Aristotelian
language would put it. The function of the agent intellect is precisely
that of producing a “universal” logical thinking in real time (abstraction;
MATTER,
VIII), “correcting its own errors”; a function that cannot be performed by
Turing's oracle or by Hofstadter's universal intelligence, but can be
always executed by the intentional intelligence of the individual human
being: hic homo intelligit , Aquinas said.
Thomas Aquinas interprets the active component of
human intelligence (“agent” intellect) as a capacity to constantly
re-define the context of the problem (“possible” intellect) in order to
adapt it to the single present datum ( adaequatio intellectus ad rem ). In this way, the passive
component of the intellect — its capacity to comprehend in a conscious way,
because it is controlled by its active counterpart— can be considered as a tabula
rasa ,
according to a famous Aristotelian expression. However, the passive
intellect is not a tabula rasa (absolute absence of any data) in itself, but rather
in respect to each new datum that the neurophysiological and cerebral
activity presents to the intellect. Aquinas' position differs from what was
pursued by the myths of absolute innatism, as meant by John Locke
(1632-1704) or by the modern Empiricists up to Popper (1902-1994),
deceiving Aristotle and the Scholastics. In fact, rather than speaking of a
tabula rasa ,
we should speak of a tabula which is constantly swept ( rasata ). Due to its capacity to
generalize (abstraction) with respect to all conditioned and singular
datum, human knowledge can be applied to, or focus on an infinity of
similar cases, becoming in such a way an “a priori” of the mind. When it
results inadequate for a new set of data (“knowing of not knowing”), the
procedure of adaptation can repeat itself indefinitely. It is evident that,
in order to avoid an infinite regression and to allow such a type of
abstraction — the other animals, which lack such abstraction, have no
progress of knowledge— a transcendent “closure” of the finite hierarchy of
inner and external senses is needed. Such a closure is nothing but a
self-consciousness of non-organic nature, hence not materially conditioned
by the past, what the Ancients used to call intellectus , having the capacity to act
immediately on itself (distinction between the “agent” and the “possible” components
of the intellect), and therefore capable of intelligere se intelligere (to know that it is knowing).
This way of solving the problem of the relationship between the spiritual
and the material component of the human psyche has two main consequences.
a) Being a “formal closure” of a hierarchy of
partially self-referential controls, as they are embedded in certain
physical structures (i.e. cerebral structures) the faculty of being subject
of rational thought must result of “non-material” type. It is a sort of
closure on itself of the informational flux, a “black hole”, a
“singularity” on the informational space that closes on itself. Moreover,
it can be partially or totally prevented by the wrong functioning of some
of its material sub-structures which control our cerebral activity and that
are informed by it, thus creating the illusion, accepted to be the truth by
some thinkers, that these cerebral structures would be the “subjects” of
human rational operations. A text by St. Thomas in his Commentary on Aristotle's De Anima , is of striking relevance for
our subject matter, even today (cf. In De Anima , I, lec. II, nn. 46-81). Here,
he distinguishes between sensory cognitive operations, which have the body
as both an object and a means of the operation itself, and which can
therefore be only partially self-referential, and intellectual cognitive
operations, which have the body only as an object, and which can therefore
be completely self-referential ( intellectus intelligit se intelligere ).
b) Given that we are dealing with the exchange of
information
between structures which control and are controlled, there is no need to
suppose any physical causality with exchange of energy and/or matter
between the spiritual mind and the cerebral structures, contrary to the
interactionism of the Platonic and Cartesian dualism. We just need the
“exchange of information” without any violation of the physical principle
of energy conservation, as we would say today. Within the context of the
ancient physiology of the “corporeal spirits”, all of this is explicitly
stated by Aquinas of the “pneumatic” (non-electric) principle of the transmission
through a distance of the nervous impulse, before the discoveries of the
Italian physiologist Galvani. In another text of the same Commentary on Aristotle's De Anima , it is explicitly stated that
the intellectual operation does not imply any physical modification ( immutatio
naturalis )
during the flux of the corporeal spirits in the brain, which is the
material organ of the internal senses, but only a formal modification ( immutatio
spiritualis )
on the flux of controls of the dispositional states of the involved organs
(cf. In De Anima , I, lec. 10, nn. 201-208). In order to be able to talk today in
similar terms, the only physical condition we need is that the physical
system we are dealing with, that is, the brain, possess a sufficient level
of complexity and a sufficient dynamical instability, derived from its
nature which is strongly and irreducibly non-linear (unpredictability on
the medium-long range behaviour, as occurs in chaotic systems; MECHANICS,
III.4). This immediately implies that energetic and informational fluxes
cannot be superimposed to each other in such systems, unlike what happens
in the stochastic systems studied by statistical mechanics and linear
thermodynamics. In fact, what characterizes chaotic dynamics that
dissipates (all living systems are “dissipative systems” and “feed” upon
free energy subtracted from the environment; CHEMISTRY, V) is that
there is a generation of information within them, that proceeds from the
microstate to the macrostate, exactly in the opposite direction, from the
macrostate to the microstate, through which the system dissipates energy.
(The system behaves in an unpredictable way with respect to what we knew
about it from the initial conditions; DETERMINISM/INDETERMINISM, II.4)
Although each individual quasi-periodical trajectory within the space of
the states of the system is predictable step by step, it is a
characteristic of the system to “jump” in a way that is absolutely
unpredictable from one trajectory to another. The unpredictability of the
macrostate is therefore generated from the microstate of the trajectories
of particles that compose the system. In a classic thermodynamic system,
the two energetic and informational fluxes proceed instead in the same
direction from the macrostate to the microstate, meaning that as soon as
the system is described in terms of its microstate, its behaviour becomes
perfectly predictable (cf. the pioneering work by R. Shaw, Strange
Attractors, Chaotic Behavior and Information Flow, in “Zeitschrift für
Naturforschung”, 36a (1981), pp. 80-112).
2. The Soul as a Spiritual Substance that
survives after Death. In the first article of the Quaestio Disputata “De Anima” , Thomas Aquinas deals with the
problem of the soul. On the one hand, being of spiritual nature, it can be
considered capable of autonomous subsistence and must be therefore in some
way a “substance”, as it was intended by the Platonic dualist. On the other
hand, according to the principles of Christian anthropology regarding the
person, it must be considered a component, and therefore “part” of a unique
psychophysical substance, that is the person. At this point it is clear that
if we do not want to fall into contradiction, the soul must be considered
as “substance”, but in a way different from what is intended for the person
in its completeness. St. Thomas solves the question by referring to the
general Aristotelian doctrine on the category of “substance”, as discussed
by the Stagirite in Book V of the Categories .
According to this doctrine, “substance” can be
intended in three main ways. In the first way, as a being that is defined
and complete in its nature and that exists as an individual (“first” substance):
in this sense substance is only referred to the person, otherwise we would
risk to fall into dualism. In the second way, the substance can be intended
as a defined and complete being that exists only in the individuals, understood as
“parts of them” (“second” substance): this is the way in which the soul was
understood as substance by the Averroists, unacceptable by Aquinas. An
analogy for the notion of substance as intended in this second sense can be
found in logic, in the notion of property that defines an “ordinary class”
of elements, a class that does not belong to itself because it is
determined by a non “autologic” predicate, that does not apply to itself.
In such a way “humanity”, intended as a property that defines all human
beings and only human beings, “is not itself a human being”, as Aristotle
would say. Though ordinary classes are not the most important ones in logic
and mathematics, they are known because they generate antinomies. In fact,
as Russell discovered, if we consider the notion of “total class of all the
ordinary classes”, the class of all the classes that do not belong to themselves, whenever
we ask ourselves if such a class does or does not belong to itself, we soon
find an antinomy. Finally, there is a third way of speaking of substance. A
substance can be considered as a being that is defined, but non complete in
its nature, and that exists in the individuals as “part of them”, a part
that, however, determines the totality to which it belongs (“third”
substance or “substantial form”). An analogy to the notion of substance as
intended in this third meaning can be found again in logic, in the notion
of property that determines a “non-ordinary class” of elements, a class
that belongs to itself because it is determined by an autologic predicate,
that can be applied to itself. For example, “polysyllabic”, intended as a
property that determines all the polysyllabic words, is itself a
polysyllabic word, and therefore belongs to the class that it defines. Regarding
this matter Aristotle used the physical, indeed biological, example of the
“feet”, that although being part of the totality of an animal individual,
nonetheless they are a part that can define the totality to which they
belong. In fact, an animal can be defined as “biped” or “quadruped”.
Returning to our own discussion, Aquinas stated that
the rational soul can be called “substance” according to this third and
last meaning, that of a determined part that defines the totality to which
it belongs. The soul is the form of a first, individual substance, that is
the person, thus it is part of that, which is however specified by this
part. Person means in fact «individual substance of a rational nature»,
according to the classic definition given by Boethius. The problem of the
survival of the rational soul after death still remains unsolved. According
to the previous proof, the soul has its own operations that it “must”
execute independently from the organs of the body. Thus, as Aquinas states,
if it has the capability to act by itself ( per se ), then it must also have the
capability to be by itself (cf. Quaestio De Anima , a. 14). However, it does
not have the being by itself as a “first” substance, but rather as a
“third” substance, as a part of that totality that is specified by it. In
other terms, in order to continue with the Aristotelian example of the hand
and the body, and of how the hand cannot survive if separated from the
body, with which the former constantly exchanges matter and energy for its vital
operations of metabolic nature, analogously the mind, in order to perform
its cognitive operations, needs to continually exchange information with
the body, and through it with the rest of the world. In other words, a
living organism can be defined as such if it is able to exert its
characteristic vital operations. Nowadays, it is possible to put an
explanted organ in a compatible chemical environment and maintain it for a
short time in order to allow it to carry out its main metabolic operations
up until the moment when it is transplanted in a new organism ( TRANSPLANTS).
The characteristic vital operations of the human mind are not, however, of
chemical-metabolic type, but rather of the “informational” type. Therefore,
how Thomas Aquinas already stated, the human mind can continue to carry out
its vital operations hence to “live” after death provided that it receives
from a source other than the body the pieces of information ( species ) on which to operate. The
question posed by the philosopher Thomas, doctor humanitatis , was answered by the
theologian Thomas, doctor angelicus . The human soul can continue to survive
temporarily in the after life, provided that it receives “through
illumination” by God, as the angels, the “information” that can enable it
to carry out its characteristic vital functions which are of the cognitive type.
The souls of the dead can continue to see the world and be in communion
with us “through God”, just as the angels which do not have a body... This
until the moment when each soul will be “transplanted” in a matter similar
to the present one that the soul will reorganize as the body of a defined
individual, that is to fully carry out once again its function of
substantial form or “third substance” of a complete human person, “first
substance”, in agreement with the biblical dogma of the final resurrection
of the bodies (cf. Quaestio De Anima , a. 15; RESURRECTION, IV).
Apart from theology, much more nowadays than in the
Middle Ages, the “dual” approach to the mind-body relationship offers to
metaphysics and anthropology new ways to indicate unexpected solutions to
the eternal problem of the survival of the mind after death. P.
Johnson-Laird at Princeton University, one of the first “critics” of the
absolutism of the functionalist paradigm in the cognitive sciences, writes
at the end of his manual of cognitive psychology: «Cognitive computation
raises many philosophical problems. It suggests an alternative to the
traditional philosophies of mind: mental processes are the computations of
the brain. This thesis is incompatible with the Dualistic philosophy that
holds mind and matter to be independent domains. It is also incompatible
with both Materialism and Idealism – the traditional attempts to abandon
one domain or the other. It implies that certain organizations of matter
enable processes to occur that represent events elsewhere in the world. It
also implies that the fabric of a computer does not matter. The way in
which it realizes its computations is — almost in both senses of the word—
immaterial. What matters is the organization of these processes. This
philosophy replaces the concept of the immortal soul with an alternative
form of immortality. There is a remote possibility that the computations of
a human mind might be captured within a medium other than a brain. A
facsimile of a human personality could be preserved within a computer
program. All living things pass on to their offspring a self-reproducing
program in their genes. Human beings, in addition, can leave behind them
some traces of their personalities in books, in pictures, in theories, and
in other cultural artefacts. We are familiar with the idea of interacting
with such artefacts in order to glean some understanding of a long-dead
person. The concept of interacting with a dynamic representation of an
individual's intellect and personality is sufficiently novel to be
disturbing. It raises moral, metaphysical and scientific issues of its own»
(Johnson-Laird, 1988, pp. 391-392)
VI. Cognitive Sciences and Dual
Theory: Perspectives to understand the Mind-Body Relationship
As we have seen, the debate on the so called
“Mind-Body Problem” is very present and open, especially in the field of
the so-called “cognitive sciences”, the last to be born inside the
encyclopedia of the modern sciences (cf. Gardner, 1987; Thagard, 1996). In
synthesis, we could say that the fundamental thesis of the cognitive
sciences is that the objective correlate, accessible to the “external” scientific
observation, of the states and/or the conscious operations, accessible only
to the subject that is experiencing them, is not only the neurophysiologic
modification of his mind (for ex., the modification of a defined
configuration of neuronal electrical stimulations which are recorded in a
electro-encephalographic trace), but also the “information processing”
implemented and executed through such neurophysiological events. In
practical terms, the states and the conscious operations, which have always
been inviolable properties of the individual subjectivity, have a double
objective correlate, accessible to the observation by other human subjects,
and thus also accessible to a scientific type of theorization: a) the
neurophysiological events; b) the information processing that takes
place through these events.
So we observe in the field of cognitive sciences a
transition from a functionalist paradigm, that has the character of a
monist-type metaphysics, to a much more well-organized paradigm that is based
upon the distinguishing features of the dual theories of mind. To
summarize, these features are: the “localization of the mind”, that we do
not recognize in any defined region of the brain, but rather in the actual
informational fluxes that connect the brain to the body and the surrounding
environment; a “non-representational” theory of knowledge, or at least not
exclusively representational; a real distinction between “energetic” and
“informational processes” in their reciprocal interdependence, based on the
complexity of the participating physical systems and on the intrinsic
unpredictability of their temporal evolution, and linked to a basic causal
determinism. This last point, on which the former two depend, emphasizes
the difference between dual and functionalist paradigms. How it was stated
earlier, the software-hardware distinction made by the functionalist paradigm has
little to do with the distinction “informational flux” – “energetic flux”
made by the dual paradigm. Unlike the second distinction, which is based on
an intrinsic characteristic of the complex dynamical systems, the first one
is substantially a distinction of the heuristic type. A sequence of formal
recursive computations of the symbolic type ( software ) has an essential isomorphism
with a finite sequence of absolutely predictable states of an elementary
mechanical system such as the TM ( hardware ), which, in turn, is
equivalent to a variety of implementations and realizations on different
compatible physical platforms. We can count from one to ten either by going
through the fingers of two hands, in touching the beads of a rosary, by
listening to the water drops from a tap, by moving the balls of an abacus,
etc.: here is the secret of a construction such as the TM and of its technologic
inventiveness, the ground forces of the informatic revolution of the
post-modern society! According to this essential equivalence between software
and hardware
we can always
be absolutely sure that anything which “functions” in a software simulation in the computer , “shall function” also in
its/their hardware implementation/s , in its actual physical realization among the many
possible. Within the functionalist paradigm this equivalence is shattered
only when facing the highly problematic construction of the “oracle” and of
its interpretation in terms of a non-computable determinism of the hardware
. On the other
hand, the distinction between informational flux and energetic flux is an
intrinsic property of all complex dynamical systems, and in particular of
dissipative structures such as all the living organisms (see above, V.1).
From here follows contemporary interest for the cognitive sciences, which
advance along a post-functionalist paradigm according to three fundamental
directions of research development in the present and in the immediate
future, to which we devote the last three sub-sections of this essay.
1. Beyond the Darwinian Paradigm, and the
Development of Non-Darwinian Theories in Biology. In order to explain the
evolution in the biological systems, the laws of unpredictability that are
manifest within the complex dynamical systems and which are the basis of
the energetic flux -informational flux distinction, can provide a
different, and perhaps more efficient principle, than the simple selection
by a random mutation ( DARWIN, IV). Unlike the introduction of a simple
aleatory variable implied by the Darwinian principle of random mutation,
the deterministic character of this unpredictability can avoid the system
spanning the whole phase space of possible mutations, but rather should
allow it to consider only significant sub-domains of it, and with a memory
mechanism that should stop it from passing over where it has already been.
The transition to chaos and the choice of islands of structural stability
through the control (and hopefully the self-control) on such transitions,
should render these systems much more promising candidates than the
stochastic systems for the study of the physical basis of biological evolution. And
this, although an exceptional physical and mathematical work in order to
characterize them in an acceptable manner would be necessary. We have only
begun climbing a mountain, the top of which we do not even see! Much more
than the “blind watchmaker” of Darwinian memory is here available: here we
are dealing with deterministic laws of the so-called self-organizing
systems (
COMPLEXITY, II), laws that should guide evolution and its attempts, making
it capable to benefit from past errors. Therefore, the selection for random
mutation would be left aside only to modulate little modifications and
adaptations within the species (for an introduction, cf. S. Kauffman, At
home in the universe , Oxford 1995; similar positions, although limited to a mere
criticism of Darwinism in G. Sermonti, Dimenticare Darwin , Milano 1999).
2. The Development of Post-Functionalist
Theories in the Cognitive Sciences. As in the biological systems the complexity of such
systems rules out the possibility that a single model can account for the
whole path of evolution, this must also be true in cognitive systems, that
occupy the peak of complexity in the biological scale. The epistemological
limit of the functionalist approach is its “representationism”. This aspect
depends upon the identification of the “mental” with the formal
calculations of a TM software . This leaves out the possibility that this approach
can account for the fundamental capacity of the intentional human
intelligence, the capacity of “symbolization”, in other words to be able to
constitute those logical symbols (the abstractive-constitutive act
belonging to the judgement of the intellectus in the Thomasian Scholastic
teaching) that should serve in a second moment to execute the typical
operations of the representational thought, the inferential reasoning (the ratio
of the
Thomasian Scholastic). This is one of the fundamental theoretical reasons
why H. Putnam repudiated that same functionalist approach which he
somehow initiated (cf. Putnam, 1975 and 1988). Moreover, and for the same
reason, the functionalism places the mind within that “methodological
solipsism”, that shows an incapacity to face what is real and to learn from
it, a quality that Carnap had already highlighted as being the fate of all
formalist approaches to the semantic problem (cf. Fodor, 1981). We
understand, then, why the major impulses to exceed the functionalist
representationism in the cognitive sciences derive from the field of
robotics: a robot does not at all need to represent anything symbolically
in a formal calculation of a TM, that assumes a static environment,
perfectly captured by that symbolization. It does need, however, to produce
adequate actions in a constant interaction with the changing environment.
Before teaching machines to simulate intelligent human beings, we should
teach them at least to be animals…
The development of an informational approach that is
able to manipulate the semantic and not only the syntactic information as
in the TM, encourages a close look at the complex dynamical systems which
are of course generators of information and not simple manipulators of bits
already constituted, as in the perfectly predictable determinism of the TM.
Mathematically speaking, a bit is a typical function that defines whether or not a
certain element belongs to a set which is already constituted (two-value
logic: yes/no): it does not have any semantic value. The semantic
information is rather what leads to a constant definition and re-definition
of the bits and of the sets associated with them. A shy attempt along these
lines is that of the fuzzy logic (many-value logic) that allow a limited
“elasticity” of the dividing line between the different sets. We are,
however, quite far from what we are asking today of the logic and
mathematics of the near future. A neurological exemplification of what we
are talking about here is given by the network of neurons in our brains
that constantly redefine the topology of connections — and not only the
statistical weights of their connections, as in the connectionist models —
in order to maximize their capacity of parallel processing (cf. Perrone, Verso
una teoria dinamica della computazione , in G. Basti e A.L. Perrone, 1996,
pp. 255-332).
All of this makes the complex systems the most natural
candidates for the study of the physical basis of the cognitive operations,
and for all of those pre-symbolic and pre-representational operations
characteristic of a bottom-up knowledge. Such a path would have its neurologic
correlate in the redefinition of the topology of connections in the network
of neurons, activated in a reciprocal manner, within the globality of the
cerebral dynamics. According to this scheme, the symbolic aspect of the
representational thought, with all of its logical-deductive operations and
associated formal calculations, would constitute the top-down path. This would have its
neurologic correlate in the operations performed by the network of fixed
connections, where the calculations are known to be equivalent to those of
a TM. The representational-symbolic moment would thus constitute a moment
that is posterior to the constitution of the logical symbol, in the same
way that the intentional, pre-symbolic moment is anterior to it. The
constitution of the symbol, in fact, needs a sort of “exit from the system”,
which is linked to the characteristic intellectual function of the mind. In
this way, the pre-symbolic moment and then the moment of the constitution
of the symbol would be in a more consequential relationship with the
representational functions of the symbolic thought. A relationship where
the Scholastic scheme intellectus-ratio could once again provide the
working paradigm.
3. Logic of Discovery vs Logic of Proof. What has been said up to now
points towards that same direction of discovery and development, in a
contemporary language, of the ancient analytical method in the study of
logic. The extraordinary development of the axiomatic method in mathematics
and modern logic has obscured the problem of the logical study of the
discovery procedures, known as the “analytical method” in the logical
pre-Cartesian tradition , with a meaning different from that used in the modern
era, which descends from a stoic and manualistic tradition of Pappus (4th
century B.C.). Much of this oversight was based on the myth of the absolute
demonstrative certainty that the deductive procedures supposedly had. In
our present times, this vision has probably reached its summit with the
Popperian statement about the absolutely irrational character of the
formulation of new hypotheses, and hence of the constitution of new axioms,
that he thought as independent of any logical procedures of investigation
(cf. K. Popper, The Logic of Scientific Discovering , 1934). The logic of discovery
is based upon procedures such as induction, abstraction, analogy that
certainly cannot aspire to the absolute certainty —as it has been known
since the times of Plato and Aristotle. We are thus facing the so-called
“inference paradox”. That is to say of the inversely proportional
relationship that exists between the level of certainty and the quantity of
information produced by an inference. In a deductive speech, all of the
truth is implicit in the premises: there is no increase in knowledge, the
quantity of information produced by deductive inference remains null (cf.
Cellucci, 1998, pp. 71f and 380). After Gödel, the impossibility to
guarantee absolute certainty in the deductive procedures, typical of the
axiomatic method, has brought about the fall of the fundamental reason of
the modern preclusion towards the analytical method as a method for the
discovery of new axioms. The absolute certainty — which only about four
centuries ago brought Spinoza to claim that the relationship between the
diameter and its circumference corresponds to p also for God— does
not exist, it is just a myth. Then, why persist in the statement of the
superiority of the axiomatic method compared to other discovery methods? If
it is true that neither one or the other produce absolute certainties, at
least the second one produces useful inferences that increase the
knowledge. This is the conclusion reached by Cellucci (1998) at the end of
his essay, which attempts to take into account the various phases of
development of the logical sciences of the past millennium. If we aim not
to assign the logic and its rigorous formalism to the absolute uselessness
(it does not increase knowledge nor does it give absolute certainties),
leaving the scientific practice to the irrationalism of ad hoc models of more and more
heuristic type, then we must rescue the role of a logical methodology in
the definition of the rules of discovery. And this, even if the wide
application of ad hoc models is a practice that today prevails in the field
of research, since it allows a free exploitation of science. All of this
means renunciation of the identification of logic with the axiomatic method
alone and renunciation of confining the research of rules to simply the
rules of the proof.
Therefore the effort of synthesis between “thought
which is thinking” and “thought which is thought”, between “pre-symbolic
intentional thought”, constitutive of logical symbols, and “symbolic
representational thought”, manipulator of already constituted symbols, that
is characteristic of the research on intelligence in the cognitive
sciences, is part of a more general research of a dynamical synthesis and
of a “stability out of equilibrium”. Life needs to be constantly
reinvented, between the logics of discovery and the logics of proof,
between the analytical method and the axiomatic method. As in the cognitive
sciences the Scholastic theories of complementarity between intellectus and ratio can constitute a model for the
research of this synthesis, in a similar way in the logical sciences this
model can be constituted by the Scholastic theories of complementarity
between logica maior and logica minor . Perhaps today more than ever “the past is in front
of us” and not just behind our back. Heidegger defined the Modern Age as
the “age of the visions of the world”, visions set against each other in a
sterile way. Particularly, as the age of “enlightening” of the modern
scientific reason set against the “obscurantism” of metaphysics and
theology, typical of the Classical Age. Today more than ever, there is the
need for dialogue and synthesis, both “synchronic” between the various
theories and doctrines, and “diachronic” between modernity and tradition.
And the need for this synthesis is not only required by the ethnic, social
and cultural pluralism, but also by the novel applications of the sciences
in fields never before explored, that add to the contributions from the
cognitive, logic and foundational research. The dialogue and the synthesis
represent an issue of survival for all, as well as for the scientific
rigour itself. The “mind-body” relationship can be regarded as an example
of this.
Gianfranco
Basti
(translated by Roger Panteri)
See also: ANALOGY; INFORMATION;
INTELLIGENCE, ARTIFICIAL; LOGIC; METAPHYSICS; SOUL;
Bibliography:
Scientific aspects:
A.M. TURING, Computing Machinery and Intelligence, “Mind” 59 (1950), pp. 433-460;
G. FREGE, Translations from the Philosophical Writings of Gottlob
Frege , edited
by Peter Geach and Max Black, Blackwell, Oxford 1970; J.A. FODOR, Methodological
Solipsism Considered as a Research Strategy in Cognitive Psychology, “The Behavioral and Brain
Sciences” 3 (1980), pp. 63-109; D.M. MACKAY, The Interdependence of
Mind and Brain, “Neuroscience”,
5 (1980), pp. 1389-1393; P. THAGARD, Mind. Introduction to
Cognitive Science ,
MIT Press, Cambridge (MA) 1996; A. CLARK, Being There. Putting
Brain, Body, and World Together Again , MIT Press, London 1997; G. BASTI, A.L. PERRONE,
Consciousness and Computability in Human Brain, “Proceedings of the
International School of Biocybernetics: Neuronal Bases and Psychological
Aspects of Consciousness”, edited by C. Taddei-Ferretti and
C. Muzio, World Scientific, Singapore-London 1999, pp. 553-566;
Interdisciplinary aspects:
H. FEIGL, The “Mental” and the “Physical”, “Concepts, theories and MBP
(Mind-Body Problem)”, edited by H. Feigl, M. Scriven,
G. Maxwell, Minnesota Univ. Press, Minneapolis 1958, pp. 370-497;
P.F. STRAWSON, Individuals, Methuen, London 1959; H. PUTNAM, Minds and
Machines, “Dimensions
of Mind”, edited by S. Hook, New York 1960; T.E. WILKERSON, Minds,
Brain and People ,
Clarendon, Oxford 1974; H. PUTMAN, Mind, Language, and Reality , Cambridge Univ. Press, Cambridge
1975; M. GREENE, Mind and Brain. The Embodied Person, “Philosophical dimensions of
the neuro-medical sciences” , edited by St. Spicker and H.T. ENGELHARDTt
JR., REIDEL, Dordrecht 1976, pp. 113-129; J.C. ECCLES,
K.R. POPPER, The Self and Its Brain. An Argument for Interactionism
, Springer
International, New York 1977; J. MARGOLIS, Persons and Minds, Reidel, Dordrecht 1978;
Th. NAGEL, Mortal questions, Cambridge Univ. Press, London-New York 1979;
M. BUNGE, The Mind-Body Problem. A Psychobiological Approach , Pergamon Press, Oxford 1980;
J.R. SEARLE, Mind, Brains and Programs. A Debate on Artificial
Intelligence, “The
Behavioral and Brain Science” 3 (1980), pp. 128-135; J.A. FODOR, The
Mind-Body Problem, “Scientific American”(1981), n.244, pp. 114-123; H.E. DREYFUS,
H. Hall (eds.), Intentionality and Cognitive Science, MIT Press, Cambridge (MA) 1982;
J.R. SEARLE, Intentionality An Essay in the Philosophy of Mind , Cambridge Univ. Press,
Cambridge (MA) 1983; J.C. ECCLES, D. ROBINSON, The Wonder of
Being Human ,
Macmillan - Free Press, London - New York 1984; P.S. CHURCHLAND, Neurophilosophy.
Toward a Unified Science of the Mind-Brain, MIT Press, Cambridge (MA) 1986;
H. GARDNER, The Mind's New Science. A History of the Cognitive
Revolution ,
Basic Books, New York 1987; W.V.O . QUINE, Mind versus Body, “Quiddities. An Intermittently
Philosophical Dictionary”, Harvard Univ. Press, Cambridge (MA) - London
1987; P.N. JOHNSON-LAIRD, The Computer and the Mind. An
Introduction to Cognitive Science , Fontana, London 1988; H. PUTNAM, Representation
and Reality ,
MIT Press, Cambridge (MA) 1988; G. BASTI, Il rapporto mente-corpo
nella filosofia e nella scienza, Edizioni Studio Domenicano, Bologna 1991;
P.S. CHURCHLAND, T. SEJNOWSKI, The Computational Brain , MIT Press, Cambridge (MA)
1992; G. BASTI, Filosofia dell'uomo, Edizioni Studio Domenicano,
Bologna 1995; R. PENROSE, Shadows of the Mind. A Search for the
Missing Science of Consciousness , Vintage, Reading 1995; G. BASTI, A.L. Perrone, Le
radici forti del pensiero debole: dalla metafisica, alla matematica, al
calcolo , Il
Poligrafo - Pontificia Università Lateranense, Padova - Roma 1996;
S. MORAVIA, L'enigma della mente. Il “mind-body problem” nel
pensiero contemporaneo, Laterza, Roma-Bari 1996 3 ; J.R. SEARLE, The Mystery of
Consciousness ,
New York Review of Books, New York 1997; C. CELLUCCI, Le ragioni
della logica, Laterza,
Roma-Bari 1998; A. OLIVERIO, L'arte di ricordare. La memoria e i suoi
segreti ,
Rizzoli, Milano 1999; D.R. HOFSTADTER, Gödel, Escher, Bach. An Eternal
Golden Braid (1979),
Penguin, London 2000; G. RYLE, The Concept of Mind (1949) Penguin, London 2000.
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