Nicolas Steno’s criticism of "L’Homme" played a major role in the early reception of Cartesianism: from the late 1660s, the "Discourse on the Anatomy of the Brain" has never ceased being used in order to discredit Descartes’s philosophy. And yet, the anatomical works of Nicolas Steno are themselves informed by Cartesian method. This paradox has led to the depiction of Steno either as a repentant Cartesian or a non-Cartesian mechanist. In this paper, I clarify such problematic labels by studying the different kinds of relationships between anthropology and anatomy that L’Homme may have used to justify. In particular, I show how Descartes’ clock analogy was used to defend two different conceptions of the articulation between anatomical observations and functional hypotheses. The confusion between those two conceptions explain the contradictory claims about the place of anatomy in Descartes’ natural philosophy.