Nature. As the word is now commonly used it excludes nature's most interesting productions-the works of man. Nature is usually taken to mean mountains, rivers, clouds and undomesticated animals and plants. I am not indifferent to this half of nature, but it interests me much less than the other half.

Any fool can tell the truth, but it requires a man of some sense to know how to lie well.

The public buys its opinions as it buys its meat, or takes in its milk, on the principle that it is cheaper to do this than to keep a cow. So it is, but the milk is more likely to be watered.

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.

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.

Cat-Ideas and Mouse-Ideas. We can never get rid of mouse-ideas completely, they keep turning up again and again, and nibble, nibble-no matter how often we drive them off. The best way to keep them down is to have a few good strong cat-ideas which will embrace them and ensure their not reappearing till they do so in another shape.

Justice is my being allowed to do whatever I like. Injustice is whatever prevents my doing so.