A man should keep his little brain attic stocked with all the furniture that he is likely to use, and the rest he can put away in the lumber-room of his library, where he can get it if he wants it.

Healthy scepticism is the basis of all accurate observation.

It is more than possible; it is probable.

I have wrought my simple plan If I give one hour of joy To the boy who’s half a man, Or the man who’s half a boy.

What one man can invent, another can discover.

It is a mistake to confound strangeness with mystery.

Life, my dear Watson, is infinitely stranger than fiction; stranger than anything which the mind of man could invent. We could not conceive the things that are merely commonplace to existence. If we could hover over this great city, remove the roofs, and peep in at the things going on, it would make all fiction, with its conventionalities and foreseen conclusions flat, stale and unprofitable.