Finally, among these more impersonal elements of the scientific spirit, a high place should be accorded to the quality of being ready to admit one’s ignorance. In this age of universal ignorance, most people who think are more or less aware of their deficiency, but as we are naturally more appreciative of our own lack than of that of others, the first impulse is a desperate effort to conceal it. Perhaps of all states of mind one of the most hostile to the scientific spirit and most incompatible with it, is pedantry, and one of the most essential elements of pedantry is precisely this disposition to conceal one’s ignorance, to make the most determined attempt to hide from others the fact that we are as helpless and as groping and as uncertain as they are. This is apt to be the vice of the teaching profession, though so many teachers are gloriously exempt from it. The pedagogue is inclined to think, I believe quite wrongly, that if he once lets his scholars see that there is anything he does not know, they will lose confidence in him forever, whereas nothing establishes their confidence so much as to appreciate his willingness to enter into their difficulties and to admit that the difficulties are human and his own. At any rate, the true man of science begins by admitting the vastness of the regions that he has not entered and can never enter, the illimitable fields of knowledge that he has not the time or the training to explore. And no man was ever more notable in this admission than Darwin. There is the general recognition of the limits of human knowledge and human capacity for knowledge: ‘The more one thinks, the more one feels the hopeless immensity of man’s ignorance.’[137] There is the recognition of the hardening of the mental arteries, so to speak, by which our flexibility is so greatly impaired and against which we cannot guard enough: ‘nearly all men past a moderate age, either in actual years or in mind, are, I am fully convinced, incapable of looking at facts under a new point of view.’[138] Further, there is not only the sense of general intellectual impotence, but the admission that, even in one’s own special line, there is much that one must necessarily miss, much that must, if not invalidate one’s conclusions, at least render them dubious and incline one to the extremest modesty in asserting them. No doubt the peculiar nature of Darwin’s work, which obliged him to touch upon all sorts of very different scientific fields, accentuated this modesty of attitude, but no one can question that it was inborn: ‘There are so many valid and weighty arguments against my notions, that you, or any one, if you wish, on the other side, will easily persuade yourself that I am wholly in error, and no doubt I am in part in error, perhaps wholly so, though I cannot see the blindness of my ways.’[139] When one goes after the truth in that spirit, one is much more likely to find it, and at any rate to teach the world