Page:On an Evolutionist Theory of Axioms.djvu/24

 not only be caused by the want of a use for them, but also by the operation of various processes, among which, for instance, are diseases, and how can it be known that some such process has not destroyed our capacity for thinking the contradictory of axioms?

But the most important difficulty is this.

The objector can hardly have reflected on the real consequences of his hypothesis. It would throw a doubt, as we have seen, on every principle however simple, self-evident, and certain it may appear, and therefore it would leave nothing even to found itself upon.

It would throw doubt also upon experience which is supposed to be our most direct access to reality, for owing to the limitation of the nervous structures to one kind of function, our minds may be misrepresenting the object.

How deep this unconscious scepticism has gone will appear still better from another aspect of the theory.

'For logical intuitions' it is said 'there is no warrant assignable other than that assignable for all intuitions accepted as certain: namely, the impossibility of thinking the opposite. Unless it be alleged that the consciousness of logical necessity has a different origin and a higher origin, it must be admitted that the consciousness of logical necessity is just as much a product of past experiences as is every other consciousness of necessity.'

It follows then, from what we have seen, that these logical intuitions must share the uncertainty of axioms. But among them we find included the principle of the syllogism, the law of excluded middle, the principle of contradiction. They are in fact those simple laws or forms of thought to which thought must conform to be thought at all. Thought therefore cannot throw any doubt on them without committing suicide.

As Aristotle has said:—