The Adam Smith problem refers to a claimed inconsistency between the Theory of Moral Sentiments and the Wealth of Nations, regarding the portrayal of human nature in these two books. Previous research predominantly resolved the claimed inconsistency by uncovering virtuous, less selfish character traits in the Wealth of Nations. This article voices caution. I acknowledge – on methodological grounds – fundamental differences regarding the portrayal of human nature in Smith’s behavioral ethics, i.e. the Theory of Moral Sentiments, as compared with (...) Smith’s economic research. The key argument is that Smith’s two books address different research problems and hence do not, need not and cannot adopt the same view of human nature – for methodological reasons, so my argument. Adam Smith scholarship overlooked that Smith himself in considerable degrees understood “economic man” as a heuristic abstraction. I connect to the philosophies of science of Imre Lakatos and Karl Popper. (shrink)