term. There is therefore an uncaused cause of everything, and this is obviously God.
In Leibniz the argument takes a somewhat different form. He argues that every particular thing in
the world is "contingent," that is to say, it would be logically possible for it not to exist; and this is
true, not only of each particular thing, but of the whole universe. Even if we suppose the universe
to have always existed, there is nothing within the universe to show why it exists. But everything
has to have a sufficient reason, according to Leibniz's philosophy; therefore the universe as a
whole must have a sufficient reason, which must be outside the universe. This sufficient reason is
God.
This argument is better than the straightforward First-Cause argument, and cannot be so easily
refuted. The First-Cause argument rests on the assumption that every series must have a first term,
which is false; for example, the series of proper fractions has no first term. But Leibniz's argument
does not depend upon the view that the universe must have had a beginning in time. The argument
is valid so long as we grant Leibniz's principle of sufficient reason, but if this principle is denied it
collapses. What exactly Leibniz meant by the principle of sufficient reason is a controversial
question. Couturat maintains that it means that every true proposition is "analytic," i.e., such that
its contradictory is self-contradictory. But this interpretation (which has support in writings that
Leibniz did not publish) belongs, if true, to the esoteric doctrine. In his published works he
maintains that there is a difference between necessary and contingent propositions, that only the
former follow from the laws of logic, and that all propositions asserting existence are contingent,
with the sole exception of the existence of God. Though God exists necessarily, He was not
compelled by logic to create the world; on the contrary, this was a free choice, motivated, but not
necessitated, by His goodness.
It is clear that Kant is right in saying that this argument depends upon the ontological argument. If
the existence of the world can only be accounted for by the existence of a necessary Being, then
there must be a Being whose essence involves existence, for that is what is meant by a necessary
Being. But if it is possible that there should be a Being whose essence involves existence, then
reason alone, without experience, can define such a Being, whose existence will follow from the
ontological argument; for everything that has to do only with