A definition is the enclosing a wilderness of idea within a wall of words.

There should be asylums for habitual teetotalers, but they would probably relapse into teetotalism as soon as they got out.

You cannot have a thing "matter" by itself which shall have no motion in it, nor yet a thing "motion" by itself which shall exist apart from matter; you must have both or neither. You can have matter moving much, or little, and in all conceivable ways; but you cannot have matter without any motion more than you can have motion without any matter that is moving.

Friends are like money, easier made than kept.

Youth is like spring, an over praised season more remarkable for biting winds than genial breezes. Autumn is the mellower season, and what we lose in flowers we more than gain in fruits.

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.

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.