“Let me add, however, that in every idea of genius or in every new human idea, or, more simply still, in every serious human idea born in anyone's brain, there is something that cannot possibly be conveyed to others, though you wrote volumes about it and spent thirty-five years in explaining your idea; something will always be left that will obstinately refuse to emerge from your head and that will remain with you for ever and you will die without having conveyed to anyone what is perhaps the most vital point of your idea.”