No slavery can be abolished without a double emancipation, and the master will benefit by freedom more than the freed-man.

There are some men who are counted great because they represent the actuality of their own age, and mirror it as it is. Such an one was Voltaire, of whom it was epigrammatically said: "he expressed everybody's thoughts better than anyone." But there are other men who attain greatness because they embody the potentiality of their own day and magically reflect the future. They express the thoughts which will be everybody's two or three centuries after them. Such as one was Descartes.

The scientific imagination always restrains itself within the limits of probability.

No delusion is greater than the notion that method and industry can make up for lack of mother-wit, either in science or in practical life.

As a natural process, of the same character as the development of a tree from its seed, or of a fowl from its egg, evolution excludes creation and all other kinds of supernatural intervention.

Books are the money of Literature, but only the counters of Science.

The clergy are at present divided into three sections: an immense body who are ignorant; a small proportion who know and are silent; and a minute minority who know and speak according to their knowledge.