philosophy really has produced some of the most monstrous egos in human history. i often point to the prefaces of the german idealists: here is what humanity has been waiting for since it awoke to consciousness; here is the culmination of our species. or nietzsche: "why i am a destiny". one of the most charming things about g.e. moore is his extreme, astonishing humility.
here are some bits of his autobiographical sketch, written for the "library of living philosophers" volume on his work (1942). (the llp exists still; it has produced great volumes on, e.g. rorty and danto under randy auxier's editorship.)
"I do not know that Russell owed to me anything except mistakes."
On his early paper "The Nature of Judgement": "I am sure the article must have been full of confusions."
On a revision of Principia Ethica: "Of course, even with all this alteration, there still remained an immense deal that was wrong with it; but I did not see that clearly at the time, though I constantly felt vaguely dissatisfied."
"When I got to know [Wittgenstein], I soon came to feel that he was much cleverer at philosophy than I was, and not only cleverer, but more profound, and with a much better insight into the sort of inquiry which was really important and best worth pursuing, and into the best method of pursuing such inquiries. . . . [The Tractatus] is a book which I admired and do admire extremely. There is of course a good deal in it which I am not able to understand."
Of his student F.P. Ramsey: "I felt distinctly nervous in lecturing before him: I was afraid he would see some gross absurdity in things which I said, of which I was quite unconscious."
believe it or not, i think it is partly things like this (which i think are honest expressions of his own self-assessment), and moore's whole anti-genius persona, that have led him to be underestimated. in particular moore has been one of many people who have been blown away by wittgenstein's super-genius performance, and moore's reputation has suffered partly by comparison to wittgenstein. and though moore should have had a much higher opinion of his own work, it is so sweet that he did not.