A banker is a fellow who lends you his umbrella when the sun is shining, but wants it back the minute it begins to rain.

— Mark Twain

A big leather-bound volume makes an ideal razor strap. A thing book is useful to stick under a table with a broken caster to steady it. A large, flat atlas can be used to cover a window with a broken pane. And a thick, old-fashioned heavy book with a clasp is the finest thing in the world to throw at a noisy cat.

— Mark Twain

A clear conscience is the sure sign of a bad memory.

— Mark Twain

A consciously exaggerated compliment is an offense.

— Mark Twain

Action speaks louder than words but not nearly as often.

— Mark Twain

Adam is fading out. It is on account of Darwin and that crowd. I can see that he is not going to last much longer. There are a plenty of signs. He is getting belittled to a germ—a little bit of a speck that you can't see without a microscope powerful enough to raise a gnat to the size of a church.('The Refuge of the Derelicts' collected in Mark Twain and John Sutton Turkey, The Devil's Race-Track: Mark Twain's Great Dark Writings (1980), 340-41. - 1980)

— Mark Twain

Adam was but human—this explains it all. He did not want the apple for the apple's sake, he wanted it only because it was forbidden. The mistake was in not forbidding the serpent; then he would have eaten the serpent.

— Mark Twain

Adam was the only man who when he said a good thing knew that nobody had said it before him.

— Mark Twain

A dog is her Hand the dog; a woman is died Frau the won[an]; a horse is was Ford, the horse; now you put that dog in the Genitive case, & is he the same dog he was before? No sir; he is was Under; put him in the Dative case & what is he? Why, he is them Hand. Now you snatch him into the accusative case & how is it with him? Why he is den Hun den? ... Read more But suppose he happens to be twins & you have to pluralize him – what then? Why sir they’ll swap that twin dog around tho’ the four cases till he’ll think he’s an entire International Dog Show all in his own person. I don’t like dogs, but I wouldn’t treat a dog like that. I wouldn’t even treat a borrowed dog that way.

— Mark Twain

Advertisements contain the only truths to be relied on in a newspaper.

— Mark Twain