Modern Physicalism. Meanwhile a totally different
issue has come to the fore and defined the freewill
question as it is now commonly understood. This is the
issue raised by the development of scientific materi-
alism. If the activity of the human person is geared
to the movements of a physical body, and if that body
is a system operating by rules of perfect and as it were
mechanical uniformity, how can the apparent freedom
of choice be real? Atomistic materialism had been a
school of Greek speculation but, as we have seen in
the case of Epicurus, carried no necessarily deter-
ministic implications. The parentage of scientific
determinism is rather to be found in astronomical
studies. It was an ancient and a medieval commonplace
that the movements of the heavenly bodies were math-
ematically exact and ideally predictable. Supposing the
“influences” of the stars upon the causality of earthly
events to be determinative, human actions will be
subject to fate. It was easy to refute the argument by
pointing out that the effect of astral influence was
highly general; different earthly agents reacted to it
variously, and men as they might choose (Aquinas,
Summa Theologica, prima, qu. cxv). But now the hy-
pothesis of the mathematical physicists was that earthly
bodies were composed of constellated atoms or of
vortices, of which the motions and mutual influences
were as mathematically exact and as predictable as
those of the stars. Physical fate seemed to have de-
scended from the skies, and so closed in upon us as
to leave no escape.
No conclusion could have been more unwelcome or
more out of tune with the times. The new science was
the expression of humanist self-assertion, of the resolve
of strong minds to make all events, however unpromis-
ing, subject to human calculation or control. The
method of physical enquiry was the voluntary inven-
tion of experimental tests and the forcing of them upon
Nature; besides, as Descartes pointed out in his Medi-
tations (i, iv, vi), it was only by a constant act of will
that one could hold the mathematico-physical hypoth-
esis itself in face of the contrary suasions of one's five
senses. What could be more preposterous, therefore,
than to make the will to intellectual world conquest
the prisoner or even the creature of the mechanism
it postulated? Descartes deserves the highest credit for
the firmness with which he held to both sides of the
duality of free mind or will and of determinate matter;
and for the honesty with which he admitted his in-
ability to construe the operative unity of the mind-
body person. There were thinkers who took the des-
perate course of denying free will, e.g., Hobbes or
Spinoza; they were violently disliked by their contem-
poraries.
The Cartesian position treated thought as the activ-
ity of a spiritual subject and found the immediate effect
of will in the formation of mental decisions. How the
clockwork body came to register or execute such deci-
sions was beyond comprehension; all one could study
on that side was the mechanism through which it did
so. For practical purposes such a division of the ground
was not inconvenient, and people could laugh at the
rage for consistency which led George Berkeley to rid
himself of dualism by reducing material objects to
“ideas,” thus making will or spirit the sole substance,
agent, or cause, subject only to the higher will of God.
It was a more serious matter when the proved fruit-
fulness of experimental physics began to suggest that
its methods and basic conceptions were the models for
all factual science, including psychology. It was then
not merely a matter of squaring a freely-choosing mind
with its mechanistically-conceived embodiment; it was
a matter of squaring an experienced exercise of free-
dom in the mind with a causal explanation of mental
experience in terms of invariant regularities. It was
David Hume who first rubbed the sore of this problem
in his Treatise of Human Nature (1739). His subtle
thought continues to exercise its spell on English-
speaking philosophers, and it is still widely held in
academic circles that an empiricist logic distilled from
the study of physical phenomena is binding upon all
thought about matters of fact; and that its applicability
to thinking and to behavior makes determinism in some
sense inescapable.
Solutions were bound to be attempted. Immanuel
Kant, in his two first Critiques, conceded to Newton
and to Hume that we are forced to think deterministi-
cally about both physical and mental processes, when
making them an object of study; but Kant also main-
tained that our need so to think is an inescapable
limitation of the human mind. Reality is not such, as
is shown by the fact that we know ourselves called
to exercise free and responsible choices in favor of the
moral law. How our power so to do fits in with the
actual order of nature lies (Kant thought) beyond our
comprehension; what we can understand is that the
very form of our cognitive processes prevents their
attaining the knowledge of things as they are in them-
selves. Kant's solution is a rational and systematic
agnosticism. His German successors attempted more
positive answers by advancing bold metaphysical
speculations concerning the subjective and the objec-
tive poles of existence (Fichte, Schelling, Hegel,
Schopenhauer).
Modern defenders of free will insist on the abstract
or diagrammatic character of our scientific knowledge
but do not need to go all the way with Kant's scientific
agnosticism. For the progress of the natural sciences
themselves has eased their task. The scientist's model
of physical reality is no longer the simple man-made
machine. Nature is seen as a complex of forces, which
by knotting themselves in combinations of increasing
elaborateness develop astonishing new properties of
joint action; and so a physical basis for free conscious-
ness becomes less starkly inconceivable.
