5. Aristotle's Theory of Matter. Aristotle, like his
two famous predecessors, hoped to synthesize the valid
insights of rival predecessors, but the rivalry now more
immediately felt was between (Platonic) “dialecticians”
and (Democritean) “physicists.” In his hylomorphism
matter ceases to be one of the conceptual extremes
whose mixture produces the experienced world and
becomes rather the neutral substratum in which con-
trary properties succeed one another: “For my defini-
tion of matter is just this—the primary substratum of
each thing, from which it comes to be without qualifica-
tion and which persists in the result” (Physics 192a
31-32). The property of matter, therefore, was poten-
tiality, the indeterminate capacity for receiving alter-
native actualizing forms. Whatever was in the world
must be actual, and existent matter, therefore, was
always under some form, e.g., that of an element, plant,
or animal, but it was called “matter” by virtue of its
continuing and further potentialities. Form involved
at once a certain proportion of material parts and an
eduction of previously unactualized properties from
(or in) them.
The altered role for matter entailed modifications
in the concepts of space and time. For both Democritus
and Plato space had been a constitutive principle of
the empirical world—as the independently existing
arena for matter or as identical with it—but for Aris-
totle the form-matter substance was ontologically pri
mary, and space was relativized into the sum total of
its “places” (Physics iv. 1-5), a network of relations
of containing and being contained among material
substances. Similarly time had now to be conceived
neither as an accident of eternal atoms nor as the
ingredient of becoming in images (since Aristotle's
material substances were neither all eternal nor all
perishable), but again relationally in the “before's” and
“after's” of given “now's.” Finally the sense in which
Aristotle found “necessity” in material change was
neither that of mathematical determinism nor of re-
sistance to the aspirations of Mind; it designated rather
the potentialities without which a given actualization
could not take place (e.g., growth without food, a saw
without metal) on the hypothesis that nature or art
were tending towards such actualization.
These contrasts can be traced to those of method.
Aristotle is disposed to begin his analyses with the
proximate stuff of this object, in this place, now, seem-
ingly tending towards this end, because of his convic-
tion that the objects of sensory experience are those
most knowable to us. Sense neither radically embroi-
ders upon nor radically impoverishes the actual consti-
tution of such objects: the empirical world is part of
actuality and the part to whose potential for producing
form our cognitive potential for reproducing it most
closely corresponds. Prime Mover and prime matter
intrigued Aristotle as they have certainly intrigued his
interpreters, but scientific or philosophic method was
not conceived as mediation between them: they were
conceptual extremes to which expanding sciences had
finally come and they were conceivable only by anal-
ogy with the more familiar concepts of what lay be-
tween (Posterior Analytics 1. 2. 71b 32-72a 6; 12. 78a
13-21). The plurality of Aristotelian sciences is a con-
sequence of conceiving philosophy as something other
than emancipation from sensory deception: different
sciences were pursued for different kinds of useful or
interesting knowledge and at many formal levels. Mat-
ter
qua matter was unintelligible at the level of abstrac-
tion of that of which it is the matter (e.g., bone is not
itself an anthropological concept), but its own formal
properties might be investigated at a more elementary
level (e.g., in physiology or medicine). Of course Aris-
totle's particular pride was that by means of the actu-
ality-potentiality distinction he thought he had given
a consistent account of change, i.e., one in which non-
being did not have to be invoked as an explanatory
principle.
These three rival fourth-century cosmological theo-
ries have historically provided paradigm conceptual
schemes for the centuries that have followed. The
sharpness and pervasiveness of the contrasts almost
tempt one to think them, in broadest outline, exhaus-
tive. However the mixing of features in subsequent
theories, to say nothing of new concrete knowledge
discovered by the sciences and the modification of the
conceptual elements which these discoveries make
necessary, limit at least somewhat the extent to which
it is helpful to characterize a theory as “Platonic” or
“Aristotelian.”
