We may now turn to the third question we set ourselves: What makes us believe In general and roughly, the answer to this question is—the vital impulse. We believe because we want to, because we have a constitutional trend toward belief. This follows from the fact that belief is a form of action, and we are driven by a passion to act. I have said this is constitutional; it is the very inwards of our vitals; there is nothing that so sums up the meaning and essence of life as the passion to do. A living organism is more than a tense spring; it is a spring growing constantly tenser and fretting to unleash its own forces. This vital tension makes all consciousness motor, and makes every idea a discharging force with inevitable consequences in overt act or intraorganic disturbance. To apply a suggestion to an active mind is like applying anything to a baby's mouth. Both alike show an instinctive tendency to close on whatever offers, be it sealing-wax or sweetmeat. We see this plainly in the workings of a savage mind. For a savage to conceive anything vividly is to believe it. Some such indiscriminate appetency of belief offers the only sufficient explanation for the vast higgledy-piggledy mass of superstition that belongs to primitive peoples.
This is, I take it, what Bain meant when he said that the chief fact of belief was primitive credulity. We are all naturally and primarily credulous; skepticism is a later development and comes from the sort of experience that makes sadder but wiser men of us. It is in life itself, in its appetency, its passion to act, that we find the prime cause of belief, which is, in fact, merely a gratification of this vital desire. As the sponge needs no other justification for absorbing nitrogen from the sea water than its own nutritive instinct, we need no other excuse for believing than the instinct of activity.
Yet this is but one side of the matter, and plainly enough the rougher, more general side of it. I eat because I want to, is but an imperfect answer to the question why I eat, and even the addition that I eat because the vital processes demand satisfaction that can be provided only by food, still leaves the matter much beclouded. In putting down belief as the gratification of a vital desire, we have only found the big, crass motive for believing. To answer fully the question, why we believe, demands that we go further. We must be prepared to find here, too, that the ground is an organic, constitutional one. The first reason for believing at all is because we are alive, not dead, and crave action, not torpor. The reason why we believe as we do, and the sort of things we do believe, is because we have the sort of constitution we have. We have seen already that, of the myriad sights the sun makes, only a slight proportion affect our retina; we have learned that of all the thousandfold possible excitants
