It is said (I do not know with what truth) that a certain Hindu thinker believed the earth to rest upon an elephant. When asked what the elephant rested upon, he replied that it rested upon a tortoise. When asked what the tortoise rested upon, he said, "I am tired of this. Suppose we change the subject." This illustrates the unsatisfactory character of the First-Cause argument.
"Is There a God?" (1952)