In this essay I consider whether the theory of organic chemistry is reducible to the theory of quantum chemistry. Using philosophical machinery developed by James Woodward, I characterize the understanding provided by both theories. Then I argue that there are systematic reasons to suspect that quantum chemistry is incapable of supporting some of the significant explanations, predictions, and applications underwritten by an understanding of theoretical organic chemistry. Consequently, even should quantum chemistry be ‘reducible to’ quantum physics in some suitable sense, (...) there are good reasons to doubt that many of the significant results of organic chemistry could be reproduced by quantum chemistry alone. (shrink)