The indirect influence of their theories has at times been considerable; but their direct influence on human thought is, and has always been, very slight.

For the plain average man, who cannot rid himself of the suspicion that the professional thinker is a professional word-juggler, has a philosophy of his own which was formulated for him by an unphilosophical people, and which, though it is now beginning to fail him, was once sufficient for all his needs.
At the present moment there are two schools of popular thought in the West.

For many centuries there was only one.

For many centuries men were content to believe that the outward and visible world--the world of their normal experience--was the all of Nature.

But they were not content to believe that it was the "all of Being." The latter conception would have said "No" to certain desires of the heart which refuse to be negatived,--desires which are as large and lofty as they are pure and deep: and in order to provide a refuge for these, men added to their belief in a natural world which was bounded by the horizon of experience (as they understood the word), the complementary belief in a world which transcended the limits of experience, and in which the dreams and hopes for which Nature could make no provision might somehow or other be realised and fulfilled.
With the development of physical science, the conception of the Supernatural has become discredited, and a materialistic monism has begun to dispute the supremacy of that dualistic philosophy which had reigned without a rival for many hundreds of years.