“From year to year, and from age to age, we see [biologists] at work, adding no doubt much to the unknown, and advancing many important interests, but, at the same time, doing little for the establishment of comprehensive views of nature. Experiments in however narrow a walk, facts of whatever minuteness, make reputations in scientific societies; all beyond is regarded with suspicion and distrust.”

“From a long view of the history of mankind, seen from, say, ten thousand years from now, there can be little doubt that the most significant event of the 19th century will be judged as Maxwell's discovery of the laws of electrodynamics. The American Civil War will pale into provincial insignificance in comparison with this important scientific event of the same decade.”

“We have no quarrel with the Freudians, but we do not put the same stress on sexual matters as they do. Sex is very important, but if it were the single most important thing in life, it would all be much simpler, and I doubt if mankind would have worked so hard to live far beyond the age when sex is the greatest joy.”

“When we no longer look at an organic being as a savage looks at a ship, as at something wholly beyond his comprehension; when we regard every production of nature as one which has had a history; when we contemplate every complex structure and instinct as the summing up of many contrivances, each useful to the possessor, nearly in the same way as when we look at any great mechanical invention as the summing up of the labour, the experience, the reason, and even the blunders of numerous workmen; when we thus view each organic being, how far more interesting, I speak from experience, will the study of natural history become!”

“I don't wish to treat you like an inferior: that is (correcting himself), I claim only such superiority as must result from twenty years' difference in age and a century's advance in experience.”

“The most important thing to remember about depression is this: you do not get the time back. It is not tacked on at the end of your life to make up for the disaster years. Whatever time is eaten by a depression is gone forever. The minutes that are ticking by as you experience the illness are minutes you will not know again.”