Actually, the prevalent, nihilist definition of man as an "animal" is very repugnant. One could say, reasonably, if one concurrs with the current scientific evidence (as I do) that Man is EVOLVED from animals, but to call man an animal is to subvert the very meaning of an animal, and obscenely denigrate humanity.
The ancient Greeks and early Christians referred to that force which gives motility to animals and humans as the soul, recognizing that there were principles common to that motility. However, the souls of animals and men are not identical, but are divided into two types, animal and rational. Please note that "animal" is an adjective; just like a "church" is properly called a "church building" (unless you actually do mean an assemby of people), an "animal" was understood to mean an "animal soul."
Animal souls are defined as inherently amoral, being motivated purely by instinct, whereas rational souls are capable of using reason to select an action in opposition to an instinctive response. Since Freud and Nietszche, mainstream society has rejected even the existence of rational thought, holding that it is, instead, instinct overly complicated to the point of complete dysfunction.
Nonetheless, the labelling of someone as an "animal" was never meant to assert that he shares morphological and genetic similarities with members of the a given phylogenic kingdom. Rather, it was said to deny the possibility of salvation or reasonable thought, because THAT is what animal literally denotes.
OK, then humans are either rocks or plants.