John Gray said this quote

“ Modern humanism is the faith that through science humankind can know the truth- and to be free. But if Darwin's theory of natural selection is true this is impossible. The human mind serves evolutionary success, not truth. To think otherwise is to resurrect the pre-Darwinian error that humans are different from all other animals. (...) There is no mechanism of selection in the history of ideas akin to that of the natural selection of genetic mutations in evolution.(...) Among humans, the best deceivers are those who deceive themselves: 'we deceive ourselves in order to deceive others better'. A lover who promises eternal fidelity s more likely to be believed if he believes his promise himself; he is no more likely to keep his promise.(...) In a competition for mates, a well-developed capacity for self-deception is an advantage. ”