The question ‘is man an animal” misses the point. It is based on the presumption that animals are mechanical, soulless beings with no inherent existence or purpose of their own, outside the larger physical ecology of life. But the question “is man an animal” implies a hope that man is above the material, a ridiculous hope if animals are not, another implication of the question. Either both man and animals are material, or they are both spiritual.
In the case that both humans and animals are material, it shouldn’t matter whether men kill each other, in any way except the sociological. For if the presumption is true, then the only purpose the individual serves is that of what gave birth to him: society and race. In the alternative case both men and animals are spiritual, in which case both types of individuals serve at least some purposes beyond the sociological or physical.
The argument might then be interjected that it might as well be the ‘spiritual’ purpose of animals to provide for the sustenance of humankind. But doesn’t this point also imply that, being spiritually equal, it might as well be the ‘spiritual’ purpose for Africans to serve as indentured slave labour for Americans, or for a rape victim to fulfil her assailant’s pleasure, or for anything we can think of? The argument is inherently a conservative one because it takes the current modus operandi of society as a given: we are meant to eat animals. But the argument falls short of reason because, although we are ‘meant’ to eat animals, we are not meant to do many similar things to each other.
It does seem to be the case that humans are primarily spiritual beings and secondly physical beings, temporarily tied to bodily existence. It follows that animals are the same. It also follows, that if our instinct to provide for ourselves at as little expense of others as possible, then this should be extended to animals. Seeing as the idea that humans need to eat meat is proven to be false and increasingly unsupported, as spiritual beings we should protect each other and follow the perfectly viable lifestyle of getting food from elsewhere.
 We tend to separate ourselves from animals on account of the outwardly observable differences: the ability to cognise and express as delicately as us. Their lifestyles do not require the same intellectual capacity as do ours neither, variably, do they require the same ability to express emotions.