If you understand something in only one way, then you don't really understand it at all. The secret of what anything means to us depends on how we've connected it to all other things we know. Well-connected representations let you turn ideas around in your mind, to envision things from many perspectives until you find one that works for you. And that's what we mean by thinking!

It would be as useless to perceive how things 'actually look' as it would be to watch the random dots on untuned television screens.

The principal activities of brains are making changes in themselves.

We turn to quantities when we can't compare the qualities of things.

To say that the universe exists is silly, because it says that the universe is one of the things in the universe. So there's something wrong with questions like, "What caused the Universe to exist?"

A couple of hundred years from now, maybe [science fiction writers] Isaac Asimov and Fred Pohl will be considered the important philosophers of the twentieth century, and the professional philosophers will almost all be forgotten, because they're just shallow and wrong, and their ideas aren't very powerful.

A computer is like a violin. You can imagine a novice trying first a phonograph and then a violin. The latter, he says, sounds terrible. That is the argument we have heard from our humanists and most of our computer scientists. Computer programs are good, they say, for particular purposes, but they aren’t flexible. Neither is a violin, or a typewriter, until you learn how to use it.