Knowledge signifies things known. Where there are no things known, there is no knowledge. Where there are no things to be known, there can be no knowledge. We have observed that every science, that is, every branch of knowledge, is compounded of certain facts, of which our sensations furnish the evidence. Where no such evidence is supplied, we are without data; we are without first premises; and when, without these, we attempt to build up a science, we do as those who raise edifices without foundations. And what do such builders construct? Castles in the air.

There is but one honest limit to the rights of a sentient being; it is where they touch the rights of another sentient being.

Love of power more frequently originates in vanity than pride (two qualities, by the way, which are often confounded) and is, consequently, yet more peculiarly the sin of little than of great minds.

We are on the earth, and they tell us of heaven; we are human beings, and they tell us of angels and devils; we are matter, and they tell us of spirit; we have five senses whereby to admit truths, and a reasoning faculty by which to build our belief upon them; and they tell us of dreams dreamed thousands of years ago, which our experience flatly contradicts.

Credulity is always a ridiculous, often a dangerous failing: it has made of many a clever man, a fool; and of many a good man, a knave.

It is in vain that we would circumscribe the power of one half of our race, and that half by far the most important and influential. If they exert it not for good, they will for evil; if they advance not knowledge, they will perpetuate ignorance. Let women stand where they may in the scale of improvement, their position decides that of the race.

Truth is but approved facts.