Semitic templates systematically encode two dimensions of verb meaning: (a) agency, the thematic role of the verb’s external argument, and (b) voice. The assumption that this form-meaning correspondence is mediated by syntax allows the parallel compositional construction of the form and the meaning of a verb from the forms and the meanings of its root and template. The root and its arguments are optionally embedded under a light verb v which introduces the agent (Hale and Keyser 1993; Kratzer 1994). But (...) this is only the unmarked case, which, in Semitic, is encoded by the simple templates. Two dimensions of markedness are introduced by two additional types of syntactic heads: (a) agency heads, which modify agency and are morphologically realized as the intensive and causative templates, and (b) voice heads, which modify voice and are morphologically realized as the passive and middle templates. Causative and middle morphemes are thus accounted for within a unified system, which, first, explains their affinity in language in general (both are found crosslinguistically as markers of transitivity alternations), and which, moreover, sheds new light on problems in the interface of semantics and morphology. One problem is the impossibility, mostly ignored in linguistic theory, of deriving the semantics of middle verbs from that of the corresponding transitive verbs. The second is explaining the identity found crosslinguistically between middle and reflexive morphology. The third is determining the grammatical function of the causee in causative constructions. (shrink)