Routledge History of Philosophy Volume IV

230 RENAISSANCE AND SEVENTEENTH-CENTURY RATIONALISM
kind of thing can serve as its definition (canon 15). Completeness in ideas can be
achieved only within the limits allowed by our ways of forming ideas, which
Gassendi stipulates in the first few canons of the logic. All our ideas come from
the senses and are in the first place ideas of individual things. Mental operations
rather than the external world are responsible for our general, analogical and
chimerical ideas (canon 3). Finally, our ideas can only aspire to perfection or
completeness if we are aware of the way in which the senses deceive us and keep
in mind these sources of deception as we form ideas (canons 11–14).
The fourth set of canons in Gassendi’s logic have a different relation to the
physics. Instead of speaking of operations of the mind that physics illuminates,
they prescribe methods of ordering thought that regulate physics and other
sciences. Only the first four canons govern investigation in science; the
remaining ten are to do with teaching what one learns. Canon 4 reintroduces the
Epicurean criteria of truth: judgements are to be submitted to sense and reason
(IL, 160). Canon 1 recommends the use of signs as a way of finding the key or
middle term in the solution of questions. Canon 3 introduces the distinction
between analysis or resolution and synthesis or composition, suggesting that
whichever has been used to arrive at an answer, the other should be used to
check it.
When he comes to the precepts governing the presentation of one’s findings
for the purposes of instruction Gassendi produces by way of illustration a
description of how to teach physics that is hard not to take as a blueprint for the
next major part of the Syntagma. He is making the point that in the sciences, as
in the productive arts, it pays to teach as if you were explaining how something
was made; in the case of natural science, how the universe is made up from its
parts:
Thus a physicist who is giving instruction in the natural sciences places as
a model before our eyes, like the larger and smaller parts of a building,
only on an extended scale, the structure of nature or the machine of the
world, the sky, the earth, all that they contain, and analysing them into
their smallest possible components takes these as the primary units which
go to make up the whole. His next step 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…until he
has unfolded the entire panoply of the world like a man who has explored
and thoroughly inspected a house which someone else has built.
(IL, 162–3)
An order very similar to the one prescribed is apparent in the sections on physics
in the Syntagma.