Do all theorems contribute equally in the context of a more geometrico exposition? In this paper it is suggested that Proclus’ account of seemingly useless theorems, as found in his In Euclidem, points to a negative answer to this question. In the first part, I reconstruct Proclus’ theory of seemingly useless theorems. Although not purely constructive, the latter facilitate the refutation of objections, limit argumentative diversity and promote interdisciplinarity (i.e., connections between different sciences). The second part discusses these functions in (...) relation to three concrete examples in the Elements of Physics, thus indicating that this theory crucially informed Proclus’ own practice in his two Elementationes. Finally, I conclude with certain broader remarks about the literary genre of Elementatio. (shrink)