It may perhaps be maintained, that with time and patience, one might train a rather stupid plough-boy to understand the differential calculus. This might be done with the help of an inward desire on the part of the boy to learn, but never otherwise. If the boy wants to learn or to improve generally, he will do so in spite of every hindrance, till in time he becomes a very different being from what he was originally. If he does not want to learn, he will not do so for any wish of another person. If he feels that he has the power he will wish; or if he wishes, he will begin to think he has the power, and try to fulfil his wishes; one cannot say which comes first, for the power and the desire go always hand in hand, or nearly so, and the whole business is nothing but a most vicious circle from first to last. But it is plain that there is more to be said on behalf of such circles than we have been in the habit of thinking. Do what we will, we must each one of us argue in a circle of our own, from which, so long as we live at all, we can by no possibility escape. I am not sure whether the frank acceptation and recognition of this fact is not the best corrective for dogmatism that we are likely to find. We can understand that a pigeon might in the course of ages grow to be a peacock if there was a persistent desire on the part of the pigeon through all these ages to do so. We know very well that this has not probably occurred in nature, inasmuch as no pigeon is at all likely to wish to be very different from what it is now. The idea of being anything very different from what it now is, would be too wide a cross with the pigeon’s other ideas for it to entertain it seriously. If the pigeon had never seen a peacock, it would not be able to conceive the idea, so as to be able to make towards it; if, on the other hand, it had seen one, it would not probably either want to become one, or think that it would be any use wanting seriously, even though it were to feel a passing fancy to be so gorgeously arrayed; it would therefore lack that faith without which no action, and with which, every action, is possible.