(Cross-posted at M-Phi)
In a recent paper, the eminent psychologist of reasoning P. Johnson-Laird says the following:
[T]he claim that naïve individuals can make deductions is controversial, because some logicians and some psychologists argue to the contrary (e.g., Oaksford & Chater, 2007). These arguments, however, make it much harder to understand how human beings were able to devise logic and mathematics if they were incapable of deductive reasoning beforehand.
This last claim strikes me as very odd, or at the very least as poorly formulated. (To be clear, I side with those, such as Oaksford and Chater, who think that deductive reasoning must be learned to be mastered and competently practiced by reasoners.) It looks like a doubtful inference to the best explanation: humans have in fact devised logic and mathematics, which are crucially based on the deductive method, so they must have been capable of deductive reasoning before that. Something like: birds had to have fully formed wings before they could fly – hum, I don’t think so… Instead, the wing analogy suggests that there must be some precursors to deductive reasoning skills in untrained reasoners, but the phylogeny of the deductive method (and to be clear, I’m speaking of cultural evolution here) would have been a gradual, self-feeding process.