The paper examines an alleged distinction claimed to exist by Van Gelder between two different, but equally acceptable ways of accounting for the systematicity of cognitive output (two “varieties of compositionality”): “concatenative compositionality” vs. “functional compositionality.” The second is supposed to provide an explanation alternative to the Language of Thought Hypothesis. I contend that, if the definition of “concatenative compositionality” is taken in a different way from the official one given by Van Gelder (but one suggested by some of his (...) formulations) then there is indeed a different sort of compositionality; however, the second variety is not an alternative to the language of thought in that case. On the other hand, if the concept of concatenative compositionality is taken in a different way, along the lines of Van Gelder's explicit definition, then there is no reason to think that there is an alternative way of explaining systematicity. (shrink)