Routledge History of Philosophy Volume IV

122 SCIENCE AND MATHEMATICS UP TO DESCARTES
elaborately, but still vaguely, in terms of what we may call differential pressures
from the vortices.
Compared with Newton on this and other issues, Descartes appears a
qualitative rather than a quantitative scientist, and this ties in with another
important methodological difference. Newton, at least rhetorically within the
context of justification, was a strong inductivist.
In experimental philosophy we are to look upon propositions inferred by
general induction from phenomena as accurately or very nearly true,
notwithstanding any contrary hypotheses that may be imagined, till such
time as other phenomena occur, by which they may either be made more
accurate, or liable to exceptions. 47
For Descartes and his followers, however, hypotheses played a crucial role. The
general structure of matter and the general laws of motion could be reached
purely by deduction, but this process could not proceed unaided to unique
explanations of particular phenomena.
When I wished to descend to [effects] that were more particular, so many
different ones were presented to me that I did not think it possible for the
human mind to distinguish the forms or species of bodies that were on
Earth from an infinity of others which could have been there if it had been
the will of God to put them there, nor consequently to relate them to our
use without coming to the causes by means of the effects and employing
several particular experiences. Following this, in passing my mind again
over all the objects which were ever presented to my sense, I indeed dare to
say that I have not remarked there anything that I could not explain
suitably enough by the principles that I have found. But I must also admit
that Nature’s power is so ample and so vast and that my principles are so
simple and so general that I hardly remark any particular effect without
immediately recognising that it can be deduced in many different fashions,
and that my greatest difficulty is usually in finding upon which of these
fashions it does depend. And for this I know no other expedient than to
seek once again some experiences which are such that their outcome will
not be the same if it is in one of the fashions that one must explain it as it will
be if it is in the other. 48
In this way Descartes gives a reasonably clear, if not unproblematic, expression
of what is often referred to as a hypothetico-deductive methodology, of a kind
which was employed by many notable scientists of the later seventeenth century.
Descartes was not alone in producing a mechanical philosophy— one need
only think of the work of Pierre Gassendi and of Thomas Hobbes—but it was his
system together with later developments and modifications that was most
generally influential. And when Aristotelian natural philosophy began at last to