This paper shows that low-level generalisations in argument structure constructions are crucial to understanding the concept of alternation: low-level generalisations inform and constrain more schematic generalisations and thus constructional meaning. On the basis of an analysis of the causative alternation in English, and more specifically of the theme, I show that each construction has its own schematic meaning. This analysis is conducted on a dataset composed of 11,554 instances of the intransitive non-causative construction and the transitive causative construction. The identification (...) of lower-level generalisations feeds into the idea that language acquisition is organic and abstractions are formed only gradually from exposure to input. So far, most of the literature on argument structure constructions has focused on the verb itself, and thus fails to capture these generalisations. I make up for this deficit through an in-depth analysis of the causative alternation. (shrink)