be his own. Nevertheless he cherished through his life the hope of discovering a kind of
generalized mathematics, which he called Characteristica Universalis, by means of which
thinking could be replaced by calculation. "If we had it," he says, "we should be able to reason in
metaphysics and morals in much the same way as in geometry and analysis." "If controversies
were to arise, there would be no more need of disputation between two philosophers than between
two accountants. For it would suffice to take their pencils in their hands, to sit down to their
slates, and to say to each other (with a friend as witness, if they liked): Let us calculate."
Leibniz based his philosophy upon two logical premisses, the law of contradiction and the law of
sufficient reason. Both depend upon the notion of an "analytic" proposition, which is one in which
the predicate is contained in the subject--for instance, "all white men are men." The law of
contradiction states that all analytic propositions are true. The law of sufficient reason (in the
esoteric system only) states that all true propositions are analytic. This applies even to what we
should regard as empirical statements about matters of fact. If I make a journey, the notion of me
must from all eternity have included the notion of this journey, which is a predicate of me. "We
may say that the nature of an individual substance, or complete being, is to have a notion so
completed that it suffices to comprehend, and to render deducible from it, all the predicates of the
subject to which this notion is attributed. Thus the quality of king, which belongs to Alexander the
Great, abstracting from the subject, is not sufficiently determined for an individual, and does not
involve other qualities of the same subject, nor all that the notion of this prince contains, whereas
God, seeing the individual notion or hecceity of Alexander, sees in it at the same time the
foundation and the reason of all the predicates which can be truly attributed to him, as e.g.
whether he would conquer Darius and Porus, even to knowing a priori (and not by experience)
whether he died a natural death or by poison, which we can only know by history."
One of the most definite statements of the basis of his metaphysic occurs in a letter to Arnauld:
"In consulting the notion which I have of every true proposition, I find that every predicate,
necessary or contingent, past, present, or future, is comprised in the notion of the subject, and I
ask no more.