 Philosophical engagement on the nature of belief, concepts, perception, mental representation, non-conceptual content, rationality, and reasoning deals both with the question of whether animals have capacities related to thought, and with questions about the nature of these capacities. Though there are a lot of contemporary discussions on these topics, this corresponds to a rather recent turn of events, since philosophy of mind has, for the most part, historically dealt only with human forms of thought. This was not out of lack of interest, but the result of the conviction that only humans were capable of thinking. Descartes, for instance, famously argued that animals’ lack of language gives us a good reason to think that they do not have any form of thought or rationality.