Leaving aside that I know humans to possess souls, I don't think it is an unreasonable claim to make that there is a real thing called a "human". I'm more than the sum of my matter: I'm me, I'm a person. You could replace each of my atoms, one by one, and T-sub-1 (Taliesin after the changes) wouldn't be importantly (and therefore, I conclude, substantially) different from T-sub-0 (Taliesin before the changes). I would survive the eradication of all my matter. Perhaps you object to the existence of things other than atoms, which would certainly be tenable, though it run directly contrary to an everyday perception of the world. However, I think we can agree that at least humans, and perhaps all animals, are discrete things. Even if you deny that, you're stuck with the problem that our entire social and legal structure rests on the presumption that humans are real and irreducible things, so that in matters of morality and common parlance, it makes good sense to continue to presume it.