“Thus what remains to us for indicating the human being’s class in the system of living nature and thus characterizing him is nothing but this: he has a character that he himself makes, in that he has the faculty of perfecting himself in accordance with ends he takes for himself; whereby he can make himself, from an animal endowed with a capacity for reason (animal rationabilis), into a rational animal (animal rationale); and as such he first, preserves himself and his species; second; exercises, instructs and brings up his species for domestic society; and third, governs it as a whole that is systematic (ordered in accordance with rational principles) and fitted for society” (Ak 7:321-322).(borrowed from Allen W. Wood's paper here) Wood goes on to say that, "Following Rousseau, Kant identifies as the distinctive feature of humanity the faculty of self-perfection. Kant rejects the traditional definition of the human being as animal rationale, allowing only that the human being is an animal rationabilis (Ak 7:321). "
This, it seems, is similar to Buddhist statements of animals: that they lack the potential for awakening. Or is this not so? Is this a later development perhaps? What do the early (Pali) texts say about animals and the difference between us (human-animals) and them (non-human animals).