Towards the end of The Human Condition, Hannah Arendt discusses the vicissitudes of the various forms of the active life and poses the triumph through the modernity of the animal laborans (worker) whose activity is related to the physical reproduction and material of the species, of the necessities of life. This was coupled with the triumph of life as ideal. In that discussion he says:
The only thing that could now be potentially immortal, as immortal as the body politic in antiquity and as individual life during the Middle Ages, was life itself, that is, the possibly everlasting life process of the species mankind (VI, 45: 321 2nd Edition Chicago University Press).
The concern for immortality is one of the ways search of to build meaning to lives that know killers in the world. The only thing that can be kept as ideal for those who perceive themselves as just one more of the beings that lives to the needs of the reproduction of life is life itself.
Now, we know that as a species, immortality is rather precarious. The common destiny of the species is extinct. Under the idea of looking for the life as an ideal maximum potential immortality of the species is insufficient (in the same way that what is the possible immortality of their own particular lineage). It is most good of all life, the biosphere in its completeness, that it might be that you could approach immortality.
Then, following that point of view there is no other thing more than to suggest that all life is equal and that the defence of the special dignity of human beings, or even of the fact that human beings grant themselves a special concern. As other animals are concerned the reproduction and of the necessities of life, how would it be possible to have something separate to humans? Against this speciesism, then the animalism where all life (at least animal) remains at the same level.
Here it is interesting that this conclusion is not required from a purely naturalizante. If human beings are a species like any other, then -as any other species- ‘naturally’ would worry more of their kind than others. And your ‘right’ to dominate other species would be based, if you use only a perspective naturalizante, in the fact that it effectively has more power than the other species exert on him (Spinoza uses a similar argument, and behold, a thinker highly consistent with the premises of your argument).
It is not there, then, from a perspective of animal rights. But from the argument of Arendt that we have drafted the conclusion animal rights is clear and obvious: Yes, only immortal life can give meaning and value to existence, the only life that can handle the load is all life without distinction of species. But, of course, that is a concern typically ‘human’ (well it may not be exclusive to us as a species, but does not apply to all the living). A argument to tell us that what is human from the point of view of particular human beings can be better than the life of the pig, but from the point of view of the pig that is not clear requires a certain point of view. McFarlane continued the argument as above with:
Again, the point here is that the priority of human suffering vis-à-vis other forms of suffering can only be maintained either on the basis of a metaphysical conception of humanity or on the basis of prejudice, usually called speciesism, both of which ought to have no place in modern sociology (Relational Sociology, Theoretical Inhumanism, p 48, paper inside the compilation Conceptualizing Relational Sociology, in Powell and Dépelteau, eds, Palgrave, 2013).
The argument may be correct, but can only be understood and discussed between living things with the capacity for symbolic, of which -until now – the only case that is clearly humans are. It would be sheer presumption of mine to assume that the pig in question (who well may be to raise a series of claims about his intelligence or sensitivity) could understand this disquisition.
In summary, the animalism would be understood then as a consequence, a result more consistent with a vision that it poses to life as the highest value and the work -understood as allowing for the reproduction of that life – as the activity par excellence.
If this were so then, by the way, it would also be a hope that is useless. If our current understanding of things is correct the entire universe will suffer death and nothing is immortal. But of course, to think sub specie aeternitatis it is always complex, and human beings find it difficult to think in the scales of the universe. It may well be, then, that the future of animalism was relatively flattering.