Many people think that each kind of animal has its own language – including apes, dolphins, bees, and ants. It’s true that all animals, including humans, transmit information by relaying useful data back and forth to one another, or by making mental associations with present or stored stimuli so as to act. Engaging in a communicative linguistic performance, however, entails having mental states insofar as beliefs, desires, intentions, hopes, dreams, fears, and the like are communicated from one being to another. So, a bee isn’t really speaking to another bee when doing his “bee dance” to transmit information about where pollen is located outside the hive. Even apes that have been taught sign language aren’t necessarily speaking – using language – to their trainers; they may be merely associating stimuli with stored memories and transmitting information. As far as we know, bees and apes don’t have experiences of joy, suffering, or regret to communicate.

[W]e can […] come to know the human soul’s mode of existence, on the basis of its activity. For insofar as it has an activity [viz., intellective cognition] that transcends material things, its existence, too, is raised above the body and does not depend on it. On the other hand, insofar as it is naturally suited to acquire immaterial cognition from what is material, the fulfilment of its nature clearly cannot occur without union with the body; for something is complete in its nature only if it has [in itself] the things that are required for the activity that is proper to its nature. Therefore, since the human soul, insofar as it is united to the body as a form, also has its existence raised above the body and does not depend on it, it is clear that the soul is established on the borderline between corporeal and separate [i.e., purely spiritual] substances.