This text examines Thomas Hobbes's critique of René Descartes regarding the nature of reasoning and the mind. Hobbes posits that reasoning is nothing more than the connection and chaining of names through the verb 'is.' According to this nominalist perspective, reason does not provide insight into the inherent nature of things; instead, it merely manipulates names based on arbitrary linguistic conventions. The crucial implication of Hobbes's argument is a strictly materialist conclusion: if reasoning depends on names, names on imagination, and imagination on the movement of physical organs, then the mind itself is nothing but motion within certain parts of an organic body. This thesis represents a radical rejection of Cartesian dualism and an attempt to provide a mechanistic explanation of cognitive processes. By grounding epistemology in linguistic conventionalism, Hobbes reduces the mental sphere to physical interactions and sequences of signifiers, significantly impacting the understanding of human consciousness in early modern philosophy.