This chapter argues that the problems that centre round reason, rationality, and intelligence are complex and elude easy, in some cases, any resolution. It examines the different approaches that have been adopted, reflecting different interests, different methodologies, and different starting assumptions. It begins where some of the modern debate started, namely with Lévy-Bruhl's proposal of a pre-logical mentality. Some comments are presented on the controversies that stemmed from that, on the question of apparently irrational beliefs, and on the conjecture that reasoning ability is unevenly distributed across modern cultures.
Keywords: reason, rationality, intelligence, pre-logical mentality, informal logic