An obstinate man does not hold opinions, but they hold him; for when he is once possessed with an error, it is, like a devil, only cast out with great difficulty.

Spare the rod and spoil the child.

They say the test of [literary power] is whether a man can write an inscription. I say, "Can he name a kitten?" And by this test I am condemned, for I cannot.

The wish to spread those opinions that we hold conducive to our own welfare is so deeply rooted in the English character that few of us can escape its influence.

If [science] tends to thicken the crust of ice on which, as it were, we are skating, it is all right. If it tries to find, or professes to have found, the solid ground at the bottom of the water it is all wrong. Our business is with the thickening of this crust by extending our knowledge downward from above, as ice gets thicker while the frost lasts; we should not try to freeze upwards from the bottom.

Flying. Whatever any other organism has been able to do man should surely be able to do also, though he may go a different way about it.

It is not sufficiently considered in the hour of exultation, that all human excellence is comparative; that no man performs much but in proportion to what other accomplish, or to the time and opportunities which have been allowed him.