We have perhaps forgotten that there was a time when we wanted to be told what an electron is. The question was never answered. . . . Something unknown is doing we don’t know what—that is what our theory amounts to. It does not sound a particularly illuminating theory. I have read something like it elsewhere: The slithy toves Did gyre and gimble in the wabe. There is the same suggestion of activity. There is the same indefiniteness as to the nature of the activity and of what it is that is acting.4
