“The ability to speak does not make you intelligent.”

“Language is courage: the ability to conceive a thought, to speak it, and by doing so to make it true.”

“Good writing does not succeed or fail on the strength of its ability to persuade. It succeeds or fails on the strength of its ability to engage you, to make you think, to give you a glimpse into someone else's head.”

“The measure of intelligence is the ability to change.”

“Intelligence is the ability to adapt to change.”

“The ability to speak exactly is intimately related to the ability to know exactly.”

“Before I go on with this short history, let me make a general observation – the test of a first-rate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function.”

“Intelligence does enable you to deny facts you dislike.”

“Intelligence is not the ability to store information, but to know where to find it.”

“Intelligence is the ability of a species to live in harmony with its environment.”