A well-worn adage advises those who set out upon a great enterprise to count the cost, yet some of the greatest enterprises have succeeded because the people who undertook them did not count the cost.

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

Irrationally held truths may be more harmful than reasoned errors.

My experience of the world is that things left to themselves don't get right.

Learn what is true in order to do what is right.

Science ... warns me to be careful how I adopt a view which jumps with my preconceptions, and to require stronger evidence for such belief than for one to which I was previously hostile. My business is to teach my aspirations to conform themselves to fact, not to try and make facts harmonize with my aspirations.

The child who has been taught to make an accurate elevation, plan, and section of a pint pot has had an admirable training in accuracy of eye and hand.