A favourite piece of advice [by William Gull] to his students was, “never disregard what a mother says;” he knew the mother’s instinct, and her perception, quickened by love, would make her a keen observer.

A formative influence on my undergraduate self was the response of a respected elder statesmen of the Oxford Zoology Department when an American visitor had just publicly disproved his favourite theory. The old man strode to the front of the lecture hall, shook the American warmly by the hand and declared in ringing, emotional tones: “My dear fellow, I wish to thank you. I have been wrong these fifteen years.” And we clapped our hands red. Can you imagine a Government Minister being cheered in the House of Commons for a similar admission? “Resign, Resign” is a much more likely response!

Between men of different studies and professions, may be observed a constant reciprocation of reproaches. The collector of shells and stones derides the folly of him who pastes leaves and flowers upon paper, pleases himself with colours that are perceptibly fading, and amasses with care what cannot be preserved. The hunter of insects stands amazed that any man can waste his short time upon lifeless matter, while many tribes of animals yet want their history. Every one is inclined not only to promote his own study, but to exclude all others from regard, and having heated his imagination with some favourite pursuit, wonders that the rest of mankind are not seized with the same passion.

Error is often nourished by good sense. … The meaning is, that the powers of the understanding are frequently employed to defend favourite errors; and that a man of sense frequently fortifies himself in his prejudices, or in false opinions which he received without examination, by such arguments as would not have occurred to a fool.

I had made considerable advance ... in calculations on my favourite numerical lunar theory, when I discovered that, under the heavy pressure of unusual matters (two transits of Venus and some eclipses) I had committed a grievous error in the first stage of giving numerical value to my theory. My spirit in the work was broken, and I have never heartily proceeded with it since.
[Concerning his calculations on the orbital motion of the Moon.]

The one [favourite fictional scientist] I can think of is Conan Doyle’s Professor Challenger, but he was a very irascible character and not a good role model.

We all pay an involuntary homage to antiquity – a “blind homage,” as Bacon calls it in his “Novum Organum,” which tends greatly to the obstruction of truth. To the great majority of mortal eyes, Time sanctifies everything that he does not destroy. The mere fact of anything being spared by the great foe makes it a favourite with us, who are sure to fall his victims.