“I have no hobby. As far as my activities beyond the bounds of my recognized profession are concerned, I take them all, without exception, very seriously. So much so, that I should be horrified by the idea that they had anything to do with hobbies—preoccupations in which I had become mindlessly infatuated in order to kill the time—had I not become hardened by experience to such examples of this now widespread, barbarous mentality.”