“Perhaps by this time the 14th century was not quite sane. If enlightened self-interest is the criterion of sanity, in the verdict of Michelet, “no epoch was more naturally mad.””

“It was van Gogh's madness that prevented him from working; the paintings themselves are ineffably sane, if sanity is to be defined in terms of exact judgment of ends and means and the power of visual analysis.”

“Madness is tonic and invigorating. It makes the sane more sane. The only ones who are unable to profit by it are the insane.”

“My name is Stephen Leeds, and I am perfectly sane. My hallucinations, however, are all quite mad.”

“The theory of games was first formalised by Von Neumann & Morgenstern (1953) in reference to human economic behaviour. Since that time, the theory has undergone extensive development… Sensibly enough, a central assumption of classical game theory is that the players will behave rationally, and according to some criterion of self-interest. Such an assumption would clearly be out of place in an evolutionary context. Instead, the criterion of rationality is replaced by that of population dynamics and stability, and the criterion of self-interest by Darwinian fitness.”

“From time to time, I do consider that I might be mad. Like any self-respecting lunatic, however, I am always quick to dismiss any doubts about my sanity.”

“In a mad world, only the mad are sane!”

“Worse than madness. Sanity.”

“Collective madness is called sanity..”

“In an age of madness, to expect to be untouched by madness is a form of madness. But the pursuit of sanity can be a form of madness, too”