Routledge History of Philosophy Volume IV

232 RENAISSANCE AND SEVENTEENTH-CENTURY RATIONALISM
thing: though there is a way of dividing it into parts in thought, the atom cannot
actually exist in parts (cf. Op. Omn. VI, 160; I, 268).
Matter coexists with the void. The existence of motion is supposed to be a sign
of this, as Gassendi has already been quoted as saying in a passage on the
indicative sign. The existence of relatively soft bodies is another sign of the
existence of a void, or, more specifically, of the existence of a void enclosed by
compound bodies. In the void there are no privileged directions and positions,
and in particular no central point toward which a body like a stone might move if
it were put into the void. A stone would move in any direction it is propelled or
attracted to move, in a straight line with uniform velocity. The Aristotelian
doctrine that there are natural positions for different substances is rejected. So is
the Epicurean idea that atoms naturally move ‘down’ in straight lines unless
deflected by an arbitrary swerve.
Gassendi has arrived at ‘the primary units’ of the material world. He thinks
that the primary units are a very large number of atoms with a large number of
different shapes. In Book IV of the Syntagma, on causation, he insists on viewing
the primary units as active, rather in the way that the troops in an army are, once
the general has given his orders (ch. 8, Brush, 418). All motion of matter is local
(Op. Omn. I, 338), even gravitation, which is effected by a kind of hooking
together of particles between bodies. Different atoms are endowed with different
kinds of mobility, as well as different shapes, and these are capable of producing
everything else observed in the physical world. Motion is at the root of effects
rather than form; causation in nature is efficient rather than formal (Op. Omn. I,
283). Gassendi takes qualitative differences to be the joint effect of the primary
qualities of atoms and their effects on our senses (Book 5, ch. 7). The variety in
biological creation he traces to God’s production in the beginning of ‘the seeds,
so to speak, of all things capable of generation, in other words, that from selected
atoms he fashioned the first seeds of all things, from which later the propagation
of species would occur by generation’ (Book 3, ch. 8, Brush, 401).
Having discussed the nature of atoms and indicated in a general way how their
possibilities of combination can explain the existence of big classes of
substances, his next task, if we are to go by the passage about teaching physics
that we quoted earlier from Part Four of Institutio Logica, is to ‘inquire into the
precise nature and pattern of the various combinations responsible for the
formation of the sun, the moon and the other heavenly bodies, and in the same
way the earth and all the many inanimate, animate and sentient beings…’. This is
indeed how he proceeds in the subsequent sections of the Syntagma. We can pass
over the astronomy and his treatment of terrestrial inanimate objects and come at
once to the area where the atomistic explanation is extended to psychology, only
to be curtailed in the interest of theological orthodoxy.
This occurs toward the beginning of Section III, Part 2, of the Syntagma, in the
book De anima. Gassendi discusses the animating principle in non-human as
well as human creatures. He thinks it is a highly mobile corporeal substance, a
flame-like tissue of very subtle atoms (Op. Omn. II, 250) spread throughout the