Contemporary philosophers and scientists remain largely resistant to attributing humanlike capacities to non-human animals, particularly great apes, for reasons that are not based on compelling empirical or theoretical grounds. Mental faculties such as reason, agency, and theory of mind are widely seen as differing in kind from functionally analogous abilities in other extant species. This dissertation appraises the current state of the animal minds literature by means of a critical genealogy charting the development of skepticism about animal cognition throughout the history of philosophy. In doing so, this project addresses the sedimentation of epistemic, linguistic, ontological, and methodological impasses that continue to shape debates over human uniqueness and limit comparative discussions of human and animal cognition.