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WHEN A person who has leaned to the purely physicalistic conception of mind sees
that it presupposes the absurdity that certain of our words do not denote what
we do denote by them, he is likely to adopt in its place the less radically
materialist conception which the late ]Professor G. S. Fullerton picturesquely
termed the "halo over the saint" theory of the mind's relation to the body.
1. Epiphenomenalism
That theory asserts that mental events have to brain events
much the same sort of relation which the saint's traditional halo supposedly has
to him: the halo is an automatic effect of his saintliness, but does not itself
cause or contribute at all to it. This is the relation which, as between brain
events and mental events, is technically termed epiphenomenalism (from the Greek
epi = beside, above + phainomai = to appear): the mental events are conceived to
be an epiphenomenon of, i.e., a phenomenon beside or above certain of the
physical events occurring in the brain; and to be a by-product, and hence an
automatic accompaniment, of cerebral activity; but never themselves to cause or
affect the latter.
This conception is not, like the radically physicalistic one, open to the charge
of absurdity since, unlike the latter, it admits that the term "mental events"
denotes events that are other than those denominated "physical" and more
specifically "cerebral." Epiphenomenalism is thus not strictly a physicalistic
monism. But virtually, i.e., for all practical purposes, it is both a monism.
and a physicalistic one, for it holds that the only occurences that ultimately
count in determining behavior are bodily ones and therefore physical. And this
means that if it were possible to do away altogether with a person's mental
states without in any way altering his brain and nervous system, he would go on
behaving exactly as usual, and nobody could tell that he no longer had a mind.
Now, obviously, if it is true as epiphenomenalism. asserts that all mental
states actually are effects of cerebral states, and also that no mental states
could be caused otherwise than directly by cerebral states, then it follows that
mental states and activities cannot possibly continue after the life of the
brain has ceased.
2. Metaphorical character of the epiphenomenalistic thesis
Let us, however, now
examine critically the epiphenomenalistic conception of the body-mind relation.
It is associated chiefly with the names of T. H. Huxley and of Shadworth
Hodgson. As defined by the latter, it is the doctrine that "the states of
consciousness, the feelings, are effects of the nature, sequence, and
combination, of the nerve states, without being themselves causes either of one
another or of changes in the nerve states which support them."(1) Huxley,
similarly, writes: "It seems to me that in men, as in brutes, there is no proof
that any state of consciousness is the cause of change in the motion of the
matter of the organism ... our mental conditions are simply the symbols in
consciousness of the changes which take place automatically in the organism; and
that ... the feeling we call volition is not the cause of a voluntary act, but
the symbol of that state of the brain which is the immediate cause of that
act."(2)
(1) Theory of Practice, London, Longmans, Green, 1870 Vol. 1:336.
(2) Collected Essays, Appleton, New York, 1893, Vol. 1:244.
In so stating, however, Huxley ignores the fact that symbolizing is not a
physical but a psychological relation: That S is a symbol of something T means
that consciousness of S in a mind M that is in a state of kind K, regularly
causes M to think of T.(3) Other metaphors used by epiphenomenalists to
characterize the relation between brain states and states of consciousness are
that consciousness is but "a spark thrown off by an engine," or (by Hodgson)
"the foam thrown up by and floating on a wave .... a mere foam, aura, or melody
arising from the brain, but without reaction upon it."(4)
(3) Cf. the writer's Symbols, Signs, and Signals,
Jl. of Symbolic Logic, Vol.
4:41-43, No. 2, June 1939.
(4) Time and Space, London, Longmans Green, 1865, P. 279. The wave-and-foam
metaphor is used by Hodgson in this book to characterize a theory of the
mind-body relation which he there attacks. But in his Theory of Practice,
published five years later, he embraces the (epiphenomenalistic) theory he had
attacked in the earlier book, and declares entirely erroneous the "double
aspect" theory he had opposed to it there (p. 283). The "wave-and-foam" metaphor
is therefore true to the radically epiphenomenalistic conception of the
mind-body relation formulated in the passage quoted previously from the later
book.
The spark and the foam in these metaphors are indeed by-products in the sense
that they do not react - or more strictly, only to a negligibly minute extent - upon
their producers. But - and this is the crucial point - they are themselves, like
their producers, purely physical; whereas states of consciousness, as we have
seen and indeed as maintained by epiphenomenalists, are non-physical events,
irreducible to terms of matter and motion. The analogy those metaphors postulate
is therefore lacking in the very respect that is essential: If states of
consciousness are effects of brain activity, they are not so in the sense in
which occurrence of the spark or the foam is an effect of the activity of the
machine or of the water under the then existing conditions; for the spark and
the foam are fragments of the machine and of the wave, but states of
consciousness are not fragments of cerebral tissue.
Hence, if mental events are effects of cerebral events, they are so in the quite
different sense that changes in the state of the brain cause changes -
modifications, modulations, alterations - in the state of the mind; the mind
thus being conceived in as substantive a manner as is the brain itself, i.e., as
something likewise capable of a variety of states, and of changes from one to
another in response to the action of certain causes.
3. Arbitrariness of the epiphenomenalistic contention as to causality between
cerebral and mental events
This brings us to another respect in which the epiphenomenalistic account of the mind-body relation is indefensible, namely,
its arbitrariness in asserting that although cerebral events cause mental
events, mental events on the contrary never cause cerebral events nor even other
mental events.
That assertion is arbitrary because if, as epiphenomenalism contends, causation
can occur between events as radically different in kind as, on the one hand,
motions of molecules or of other physical particles in the brain and, on the
other, mental events, then no theoretical reason remains at all why causation
should not be equally possible and should not actually occur in the converse
direction; that is, causation of brain events by mental events.
The paradoxical character of the contention that states of consciousness never
determine or in the least direct the activities of the body is perhaps most
glaring when, as Ruyer points out, one considers on the one hand painful states
of consciousness and desire to prevent them and, on the other, man's invention
and employment of anaesthetics: "The invention of anaesthetics by man supposes
that disagreeable states of consciousness have incited man to seek means to
suppress such states of consciousness. If, according to the (epiphenomenalistic)
hypothesis, disagreeable consciousness is inefficacious, how, on the one hand,
can it originate an action? On the other hand, how can a chain of pure causality
(as between brain events) so manage as not to 'become' such as to get
accompanied by disagreeable consciousness?'(5)
(5) Raymond Ruyer: Neofinalisme, Presses Universitaires de France, Paris 1952,
p. 24.
As a matter of fact, the empirical evidence one has for concluding that
occurrence, for example, of the mental event consisting of decision to raise
one's arm causes the physical rising of the arm, is of exactly the same form as
the empirical evidence one has for concluding - as the epiphenomenalist so
readily does - that the physical event consisting of burning the skin, - or,
more directly, the brain event thereby induced - causes the mental event called
pain. If either the conception of causality which the so-called "method" of
Single Difference defines, or the regularity-of-sequence conception of
causality, warrants the latter conclusion, then, since the one or the other is
likewise the conception of causality through which the former conclusion is
reached, that conclusion is equally warranted.
On the other hand. if the supposition that a volition or idea or other mental
event can push or pull or somehow otherwise move a physical molecule were
rejected, either on the ground of its being absurd or on the ground that it
would constitute a violation of the principle of the conservation of energy,
then the supposition that motion of a physical molecule in the brain can cause a
mental, i.e., a non-physical event, would have to be rejected also, since it
would involve the converse absurdity or would involve violation of that same
principle.
Again, if it is argued that mutilations of the brain, whether experimental or
accidental, are known to cause alterations of specific kinds in the mental
states and activities connected with that brain, it must then be pointed out
that, as psychosomatic medicine now recognizes, mental states of certain kinds
generate corresponding somatic defects; so that here too causation is sometimes
from mind to body, as well as sometimes from body to mind.
The preceding considerations, then, make amply evident that the
epiphenomenalistic theory of the relation between body and mind is altogether
arbitrary in holding that causation as between brain and mind is always from
brain to mind and never from mind to brain.
Furthermore, it is arbitrary also in holding that all mental states are effects
of brain states; for this is not known, but only that some mental states - of
which sensations are the most obvious examples - are so. Moreover, observation, as
distinguished from epiphenomenalistic dogma, testifies that, in any case of
association of ideas, occurrence of the first is what causes occurrence of the
second. Nor do we know that mental states of certain kinds, which normally have
physical causes, might not - although perhaps with more or less different specific
content - be caused otherwise than physically. This possibility is suggested by
the occurrence of visions, apparitions, dreams, and other forms of
hallucination; for in all such cases mental states indistinguishable at the time
from sensations are caused somehow otherwise than, as normally, by stimulation
of the sense organs.(6) That even then those states are always and wholly
effects of cerebral states is not a matter of knowledge but only of faithfully epiphenomenalistic speculative extrapolation.
(6) See, for instance, the remarkable case of a waking hallucination reported in
Vol. XVIII of the Proc. of the Society for Psychical Research, pp. 308-322.
Moreover, if the capacity of mescalin or of lysergic acid diethylamide to induce
hallucinations by physical means should be cited, the comment would then have to
be that what needs to be accounted for is not only that hallucinations then
occur, but also what specifically their content - which in fact varies greatly
- happens to be. That is, do these drugs cause what they cause one to see
in a sense comparable to that in which a painter's action causes the picture he
paints and sees; or, on the contrary, do they cause one only to see what one
then sees, in a manner analogous to that in which the raising of the blind of a
window on a train causes a passenger in the train to see the landscape which
happens to be outside at the time?
These remarks are not offered as an argument that, since we do not know that the
specific content of hallucinations has cerebral causes, therefore probably its
causes are non-cerebral; for so to argue would be to become guilty of the
fallacy argumentum ad ignorantiam. They are offered only to underline that this
very fallacy infects the contention that, if, as in fact is the case we do not
know that only some mental states are cerebrally caused, then probably all of
them are so caused.
That all mental states have exclusively cerebral causes is thus only postulated;
and - notwithstanding the contrary empirical evidence we cited - postulated only out
of pious wish to have an at least virtual physicalistic monism, since a strict
physicalistic one is ruled out by the absurdity pointed out in Ch. VIII, which
it involves. What the epiphenomenalist does is to erect tacitly into a creed as
to the nature of all reality what in fact is only the program of the sciences
dedicated to the study of the material world - the program, namely, of explaining
in terms of physical causes everything that happens to be capable of being so
explained.
The upshot is then that the epiphenomenalistic conception of the relation
between brain and mind not only is not known to be true, but even arbitrarily
disregards positive empirical facts which appear to invalidate it. Hence the
consequence that would follow if that conception were true - namely that no mental
activities or experiences can occur after the brain has died - is itself not known
to be true. That is, so far as goes anything that epiphenomenalists have shown
to the contrary, after-death mental life - at least of certain kinds - remains
both a theoretical and an empirical possibility.
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