The study of the complication of motives that prompts a man like Darwin, and many others, to reveal and establish a great scientific discovery in spite of violent opposition is profoundly curious and profitable. It seems to me that a main element in these motives, with the scientist, as with the artist and the politician and the actor and the preacher and the athlete alike, is ambition. As Darwin himself expresses it: ‘The action of unconscious selection, as far as pigeons are concerned, depends on a universal principle in human nature, namely on our rivalry, and desire to outdo our neighbors. We see this in every fleeting fashion, even in our dress.’[410] And again: ‘Man is the rival of other men; he delights in competition, and this leads to ambition which passes too easily into selfishness.’[411] The concrete essence of ambition is the desire for fame, to have one’s efforts, one’s powers, one’s achievement, one’s ego, recognized, appraised, established by the applause and commendation of one’s fellow-men. And surely this desire in itself is a natural and even a laudable one, leading, as it does, to most useful and enduring accomplishment. The drawback is that the thirst for glory is so enticing, so overmastering, that it seduces men into strange and dubious methods of obtaining it. Glory, or notoriety, is got so often by base means, the trickster and the charlatan can so often snatch its rewards and laurels from honest labor and even from genius divinely endowed, that sincere and earnest spirits are impelled to disclaim the pursuit altogether, and to insist, perhaps with genuine self-deception, that fame as a motive hardly enters into their struggle at all. This contention is maintained the more easily, since it is evident that other motives, and those most powerful, do enter in. There is the restless, ever active disposition of human nature to be doing something, almost no matter what. To work, to create, to achieve, is to live. Nothing else can properly be called life. To have done great things, to be doing them, makes you feel that you exist, and why should you vex yourself with what other men think of them? Then for the scientist there is the sheer delight of adding one grain of truth to the slow accumulation of the centuries, as for the artist there is the splendid sense of having created something beautiful. You know it, you feel it: what do the others matter? And there is further the rich reward of believing, or hoping, that you are doing even a little to help or to enlighten your fellow-men, whether they are ever aware of it or not. Few things are more soothing or cheering to the soul than that. So that there have been thinkers and there have been artists who have said, and perhaps sincerely thought: ‘I care not if some other man gets the credit of my work altogether. So the work is done, and I have done it, and know that I have done it, and it endures, and is worthy to endure, what