The evidence is clear and overwhelming that both the detection of deception and often its propagation have been major forces favoring the evolution of intelligence. It is perhaps ironic that dishonesty has often been the file against which intellectual tool for truth have been sharpened.
Robert Trivers, The Folly of Fools: The Logic of Deceit and Self-Deception in Human Life, New York, 2011, p. 5
Freud had saddled Western culture with the bizarre notion that the least considered utterances were always, magically, the truest—that reflection added nothing, and the ego merely censored or lied. It was an idea born more of convenience than anything else: he’d identified the part of the mind easiest to circumvent—with tricks like free association—and then declared the product of all that remained to be ‘honest’.
Greg Egan, Distress, London, 1995, pp. 82-83