It is profitable also to watch Darwin’s attitude towards argument, the direct interchange of view by those who take different sides of a case and are at once eager to advance their own and to detect the flaws in their opponent’s. It is very evident that he was not a quick and natural arguer, as was Huxley, for instance. His son says: ‘He used to say of himself that he was not quick enough to hold an argument with any one, and I think this was true. Unless it was a subject on which he was just then at work, he could not get the train of argument into working order quickly enough.’[71] And Darwin confesses the same thing with his unfailing, charming naïveté, in a letter to Hooker: ‘I am astonished at your success and audacity. It is something unintelligible to me how any one can argue in public like orators do. I had no idea you had this power.’[72] Arguments haunted him, agitated him, disturbed him. Active discussion was apt to be followed by a broken night, filled with the things that might and should have been said and were not. Even of a conversation quite remote from his scientific interest he says: ‘Your slave discussion disturbed me much; but as you would care no more for my opinion on this head than for the ashes of this letter, I will say nothing except that it gave me some sleepless, most uncomfortable hours.’[73] The gift I have before suggested, of getting outside of your own position and judging it as another would, while it benefits the results of argument, is most hampering in the process, since one finds oneself stating one’s adversary’s case sometimes more forcibly than he does himself. Darwin often repeats the principle I have quoted earlier, of recognizing and recording objections, and he sums up his method in regard to his main theory: ‘I have for some time determined to give the arguments on _both_ sides (as far as I could) instead of arguing on the mutability side alone.’[74] Yet in spite of all the strain and effort of argument, he liked it and believed in it. In the concluding chapter of the ‘Origin’ he says: ‘This whole volume is one long argument.’[75] It certainly is. Elsewhere he says of a personal conversation: ‘I was particularly glad of our discussion after dinner; fighting a battle with you always clears my mind wonderfully.’[76] To get the mind clear, to illuminate and elucidate the complicated tangles of thought and theory, that was always the object, and if verbal battles helped it on, they were welcome.