This discussion-paper aims to present a concrete, albeit untested, hypothesis regarding how second-language learning lessons could prove useful in diagnosing essential signs of confusion, misunderstanding, or of any other kind of cognitive blunder which affects the scientific knowledge of late primary-education students (aged 10-12). In opposition to the somewhat rigid means of evaluation normally employed in content-oriented subjects such as History, Biology, etc. -exams, tests and written assignments which are carried out, as a rule, in the children's native language-, this paper defends that the accuracy of the students' knowledge may also, though not only, be evaluated by paying attention to their creative discourse; furthermore, to the creative discourse they produce in a second-language. In fact, such discourse would fulfill a similar role to the one held by free-association in psycho-analytic therapy. In this case, however, the teacher's attention would not focus on pupils' unconscious thoughts or desires, but on any sign of ignorance or misunderstanding revealed in this imaginative use of language. Accordingly, story-telling activities, wishful expressions, descriptions of ideal societies, ideal animals, ideal families, etc., could all offer a viable side-road to access the child's conceptual knowledge in relation to scientific contents. Children's acquaintance with the basic aspects of the social and natural sciences, as dictated by their education curriculum, could be further analyzed in this way.