The great question which, in all ages, has disturbed mankind, and brought on them the greatest part of their mischiefs ... has been, not whether be power in the world, nor whence it came, but who should have it.

Nobody is made anything by hearing of rules, or laying them up in his memory; practice must settle the habit of doing, without reflecting on the rule; and you may as well hope to make a good painter, or musician, extempore, by a lecture and instruction in the arts of music and painting, as a coherent thinker, or a strict reasoner, by a set of rules, showing him wherein right reasoning consists.

We are all a sort of chameleons, that still take a tincture from things near us: nor is it to be wondered at in children, who better understand what they see, than what they hear.

It is of great use to the sailor to know the length of his line, though he cannot with it fathom all the depths of the ocean.

Mathematical proofs, like diamonds, are hard and clear, and will be touched with nothing but strict reasoning.

If by gaining knowledge we destroy our health, we labour for a thing that will be useless in our hands.

There cannot any one moral rule be proposed whereof a man may not justly demand a reason.