Routledge History of Philosophy Volume IV

400 GLOSSARY
modus tollens:
monad:
monism:
naturalism:
naturalism, ethical:
necessity, hypothetical:
affirming and the mind which affirms. Spinoza
adapted the modal terminology to his monistic (see
‘monism’) metaphysics.
‘the mood that denies’. An inference of the form ‘If
p, then q; but not q; therefore not p’. This is contrasted
with ‘modus ponens’ (‘the mood that affirms’), which
has the form ‘If p, then q; but p; therefore q’.
in classical Greek, ‘monas’ meant a unit. Leibniz used
the term to refer to his simple, non-extended
substances, each of which is genuinely one.
a term which usually refers to the doctrine that there
is one and only one substance, and that particular
things are not substances but are forms of the one
substance. However, during the twentieth century the
term has been used in such a way as to be compatible
with the existence of several substances, provided that
these are of the same kind. For example, ‘neutral
monism’ is the theory that minds and bodies are not
substances of fundamentally different kinds; to talk
of minds and bodies is to group in different ways
certain basic entities which are all of the same kind
and of which no one is either mental or physical.
as a view about what exists and how it is known,
naturalism is the thesis that everything that exists or
happens is that which is studied by the sciences,
whether natural or human; there is no place for
supernatural beings such as God. The term is also used
in place of ‘ethical naturalism’ (q.v.).
the thesis that ethical concepts can be defined in terms
of statements of fact, such as ‘That is morally good
which produces the greatest happiness of the greatest
number’.
an Aristotelian concept (see Physics, II, 9), used by
Leibniz in his attempt to reconcile the freedom of the
human will with his thesis that everything has a cause.
Something has hypothetical necessity if it is
necessary, given that such and such is the case. Thus,
the present state of the world is hypothetically
necessary in that it follows, in accordance with the
laws of nature, from any given preceding state.
Hypothetical necessity is opposed by Leibniz to
‘logical’ or ‘metaphysical’ necessity, which is the
necessity possessed by a truth whose denial would
involve a contradiction.