History of Western Philosophy - Bertrand Russell [333]
Kant encountered this argument by maintaining that 'existence' is not a predicate. Another kind of refutation results from my theory of descriptions. The argument does not, to a modern mind, seem very convincing, but it is easier to feel convinced that it must be fallacious than it is to find out precisely where the fallacy lies.
The cosmological argument is more plausible than the ontological argument. It is a form of the First-Cause argument, which is itself derived from Aristotle's argument of the unmoved mover. The First-Cause argument is simple. It points out that everything finite has a cause, which in turn had a cause, and so on. This series of previous causes cannot, it is maintained, be infinite, and the first term in the series must itself be uncaused, since otherwise it would not be the first 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 essence can be known independently of experience—such at least is Leibniz's view. The apparent greater plausibility of the cosmological as opposed to the ontological argument is therefore deceptive.
The argument from the eternal truths is a little difficult to state precisely. Roughly, the argument is this: Such a statement as 'it is raining' is sometimes true and sometimes false, but 'two and two are four' is always true. All