Our character is determined more by the absence of certain experiences than by the experiences we have undergone.
It is worth mentioning, for future reference, that the creative power which bubbles so pleasantly in beginning a new book quiets down after a time, and one goes on more steadily. Doubts creep in. Then one becomes resigned. Determination not to give in, and the sense of an impending shape keep one at it more than anything.
It is my earnest desire that some of you should carry on this scientific work and keep for your ambition the determination to make a permanent contribution to science.
If you haven’t the strength to impose your own terms upon life, you must accept the terms it offers you.