Routledge History of Philosophy Volume IV

GLOSSARY 403
premiss (premise):
procatarctic:
Pyrrhonism:
qualities, primary and
secondary:
rationalism:
reductio ad absurdum:
reductionism:
(plural, ‘premisses’ or ‘premises’). The proposition
or propositions from which the conclusion of an
argument follows.
see ‘cause, procatarctic’.
a form of ancient scepticism (q.v.), revived in the
Renaissance when the writings of the Pyrrhonist
philosopher Sextus Empiricus (fl. c. 200 AD) were
published in the 1560s. Unlike some sceptics, the
Pyrrhonists did not say that nothing can be known; in
their view, such an assertion was as dogmatic as the
assertion that something can be known. Rather, they
proposed that we should suspend judgement about all
claims to knowledge when these go beyond
appearances.
these terms express a distinction drawn by some
philosophers between (a) the qualities which a
physical object really has (its ‘primary’ qualities: e.g.
extension and solidity) and (b) the qualities which it
does not really have, but is perceived as having, and
which can be explained in terms of the primary
qualities. These are its ‘secondary qualities’: e.g.
colour and sound.
(a) in one sense of the term, rationalism has a relation
to religious belief. A rationalist in this sense is
someone who tries to eliminate from such beliefs
everything that does not satisfy rational standards.
This may lead to a total rejection of religion; however,
rationalism is compatible with religious belief of a
sort, as in the case of deism (q.v.). For example,
Voltaire was a deist, but would normally be regarded
as a rationalist in sense (a) of the term, (b) The
philosophical sense of the term ‘rationalism’ is
different. In this sense, rationalism is the thesis that it
is possible to obtain, simply by reasoning from
propositions which cannot rationally be denied, the
knowledge of necessary truths about what exists.
Spinoza combined both sorts of rationalism, but by
no means all rationalists in sense (a) are rationalists
in the second sense.
a means of proving a proposition by showing that the
assumption of its falsity leads to an absurdity, in the
sense of a logical contradiction.
a reductionist tries to minimize the number of basic
entities that are recognized in our conceptual