1. Changes in the Concept of Matter. Given the
range of materials on concepts of matter from, say,
Nicolas of Cusa (1401-64) to Isaac Newton (1640-
1727) it is useful to try to summarize, roughly, while
recognizing the inevitability of exceptions, what dis-
tinguishes the modern view from that of the preceding
period. The chronological account that follows there-
after can then be selective and merely illustrative.
The medieval universe, whether described by Plato-
nists or Aristotelians, was hierarchically ordered, e.g.,
in the astronomical distinction between celestial and
terrestrial spheres, the biological order of rational,
animal, and vegetable souls, and the alchemical divi-
sion of nobler and baser materials; and almost univer-
sally the greater the material component of any nature,
the lower in the hierarchy it fell. This view was sup
planted by an effort to account for all of physical
nature by one homogeneous matter operating
throughout by one set of mechanical laws. There were
no doubt some elements of coincidence in the mutual
reinforcement given to this rejection of hierarchy by
the growing success of Copernicus, Gilbert, Kepler,
Descartes, and Newton in applying the principles of
terrestrial mechanics to celestial movement on the one
hand, and the emphasis of the Protestant Reformers
on the absolute and unmediated sovereignty of God
over every creature on the other. Perhaps a majority
of the working “natural philosophers” of the early
modern period felt that double motivation.
It is relatively easy to detect in the Middle Ages
a pattern of transition from the early Platonic syntheses
(patristics), to an Aristotelian system of sciences (thir-
teenth century onwards), to late medieval analysis and
critique (especially from the fourteenth century on-
wards); and the increasingly “atomistic” modes of
thought even went so far in Nicolas of Autrecourt (fl.
1340), a philosopher-theologian of the Ockhamist
school, as the claim that the hypothesis of Lucretius
was preferable to that of Aristotle. The Church was
able to repress heretical speculation in Nicolas, but
increasingly in the Renaissance the whole range of
ancient methods and systems (Platonic corpus by
Ficino's translation, 1463-69; Lucretius by 1417) was
again available—the Platonic conception of parts as
dependent aspects of wholes, the Democritean under-
standing of wholes as collections of independent parts,
and the Aristotelian distinction of essential from acci-
dental in the experientially given. All these resources
were exploited by various thinkers and in various mix-
tures, but it was the long-neglected possibilities of
atomism that were most revolutionary. As the “closed
world,” centered first on the earth and then on the sun,
became observationally and conceptually untenable,
atomism's postulate of an “infinite universe” seemed
scientifically confirmed.
The enthusiasm for “corpuscular philosophy,” found
in some guise or other in all the most productive
thinkers of the time, meant that quantitative or “pri-
mary” properties such as extension, duration, and ve-
locity—properties the mathematical statement of
which corresponded in fairly direct fashion to what
was actually experienced—became the basis of causal
explanations. The old “substantial forms” and “sensible
species,” which were incapable of such equivalent
mathematical statement, were rejected as “occult
qualities,” unverifiable and redundant, and as “second-
ary” properties resulting from the action of the “pri-
mary” ones but having no status other than that of
“appearance” in the mind. It further followed that
teleological explanations, certainly in terms of the ends
inherent in the natures of particular macroscopic spe-
cies, and, more cautiously, in terms of the general
welfare of nature as a whole, were increasingly rejected
as unphilosophical. The “great book” of the universe,
said Galileo, “is written in the mathematical language—
triangles, circles, and other geometrical figures, without
whose help it is impossible to comprehend a single
word of it...” (
Il saggiatore, sec. 6).
What substituted for patterns of behavior immanent
in the forms of a hierarchy of beings from enmattered
elements, plants, and animals to immaterial “Intelli-
gences” and God were “laws of nature,” usually con-
ceived as externally imposed upon matter at its crea-
tion by God. Descartes in some ways carried this
tendency further than anyone else. He first correctly
formulated the principle of inertia in terms of rest or
uniform rectilinear motion. Making sheer geometrical
extension the essence of material body, and postulating
a law of the conservation of motion (whatever the
directional variations), he found it necessary to intro-
duce force or causal agency (as contrasted with inertial
transfer of motion) at only one point, God's creative
and sustaining fiat. Thinkers such as Spinoza, Male-
branche, Leibniz, and Newton were unwilling to cen-
tralize physical causality in exactly the Cartesian way,
but the occasionalism of Malebranche, the pre-
established harmony of Leibniz, and even the monism
of Spinoza show Descartes' influence or the same influ-
ences that persuaded him. Cum deus calculat fit
mundus (“As God calculates so the world happens”),
and the confidence that the laws of nature would be
relatively few and rationally ordered was sustained by
the belief in their origin in one supremely rational
mind.
While, therefore, there was a revival of atomistic
and mechanistic modes of thought in the sixteenth and
seventeenth centuries, there was a difference, and it
also helps to account for their wider influence in mod-
ern times. Given the sociological position of the insti-
tutional churches, early science would certainly have
had a far more stormy reception if it had not been
disposed to use God as the ready-to-hand Deus ex ma-
china in many a difficulty, or supposed difficulty, where
it turned out to be convenient to think of the machina
ex deo. Thus most—not all—of the champions of cor-
puscular philosophy held that God had first created
the atoms; that the laws by which they were governed,
however mechanical, were directed to providential
ends; and that human consciousness represented a sub-
stance as real as, though radically different from, phys-
ical matter.
In metaphysical terms this very often meant that
materialistic themes were combined with Platonic as
in Descartes, Spinoza, and Leibniz. An interesting case
in point is on the question of the infinite divisibility
of matter, denied by ancient atomism, maintained by
Descartes and his active school. This was a traditional
Platonist doctrine, for such diffuseness at the lower
extremity of the “chain of being” was the appropriate
dialectical contrary to the absolute and spiritual Unity
at its head. It seems clear that Descartes could ignore
the atomists' argument that existence must finally have
its irreducible units, because his matter or extension
was an imperfect grade of substance (less perfect than
thinking substance, for example) which existed only on
the continuing sufferance of God. When Leibniz re-
vived the argument that there could be no plura entia
without the final unum ens (“no multitude without
units”), but this time on behalf of the psychical monads
of which he conceived matter to be composed, he was
as he himself realized, both more atomistic and more
scholastic.
These generalizations may now be supplemented
with a fuller description of the theories of matter of
two thinkers, one of the sixteenth, one of the seven-
teenth century, illustrative, though something more
than typical, of their ages: Giordano Bruno and Isaac
Newton.
