The author criticizes, from an epistemological point of view, the "naturalist argument" which underlies a number of current propositions bearing on second language learning, be it in "natural" or in formal contexts. In the first section, he contests Piaget's (1957) interpretation of Comenius' Didacta Magna (he is presented as "one of the precursors of the genetic principle in developmental psychology"), because it completely occults what Comenius borrows from Aristotle's "practical syllogism"as it has been reinterpreted by the christian tradition. In a second section, it is shown how Krashen's "Acquisition/Learning Hypothesis" follows not only from the "two brain theory", as it was formulated in the 1970s, but also from certain "naturalist" presuppositions which have been widely accepted by the Western language teaching tradition, and which can be found in most of the recent "acquistion studies". Finally, in a third section, the author proposes the idea (based on Bruner, 1987; Jolibert, 1987 and Bronckart, 1996) that the learning of a language depends on a form of "social learning" at least as much as on a genetically inherited neurobiological device, about which we still have little knowledge, in spite of recent progress on the part of the cognitive sciences.
