This paper characterizes the increase in ‘scientific understanding’ that resulted from the Ingold Revolution in organic chemistry. By describing both the sorts of explanations facilitated by Ingold’s Revolution and the sense in which organic chemistry was ‘unified’ by adopting these approaches to explanation, one can appreciate how this revolution led to a dramatic qualitative improvement in organic chemists’ understanding of the phenomena that they study. The explanatory unification responsible for this transformation in organic chemistry is contrasted with contemporary philosophical accounts (...) of unification and its relationship to both scientific understanding and explanation. (shrink)