Thinking is complex, slow and cognitively expensive and rationality
does not guarantee success. Rationality only attempts to maximize the
likelihood of success, which places it squarely on a par with natural
selection. De Sousa's excellent book sets out to investigate the
relationship between rationality and natural selection and answer the
question what is so good about thinking? Link:
http://metapsychology.mentalhelp.net/poc/view_doc.php?type=book&id=4347###