Animalism holds that we are animals. This is a pretty common-sense view. We are clearly mammals, and mammals are animals.
However, there is a common objection: cerebrum transplants. As the objection goes, if your cerebrum is transplanted from your skull to a different skull (or to a supportive vat), you follow the cerebrum, while the animal stays with the lower brain and the rest of the body. So you are not the animal.
Let me say something that will sound silly: This objection is guilty of biologism about animals. The biologism here consists in the claim that we should take how biologists think about the continuity of animal life to be normative for how we should think about the identity of animals. You might think it’s obvious that we should engage in biologism about animals. But biologists are not metaphysicians, and the question of the metaphysical identity over time of animals does not really enter into the empirical investigations biologists engage in.
On what I think is the correct metaphysics of animals, the identity of an organism over time is grounded in the persistence of the animal’s soul or form, a metaphysical feature of the animal which is largely beyond the interest of contemporary biologists. Moreover, the animal’s form is responsible for its teleological structure, which defines what the animal’s flourishing is, and what is and is not central to that flourishing. It is plausible—though not necessary—to think that the form tends to remain with those components of the animal that are more central to its flourishing as the kind of thing it is.
In the case of homo sapiens, central to its flourishing is the exercise of the excellences of intellect and will. And the cerebrum is more directly involved in these exercises than any other part of the body, so it is plausible to think that the human animal goes with the cerebrum in a transplant.
Biologistically speaking, it is tempting to think of the intellect and will as subserving the animal functions of homeostatic maintenance, growth and reproduction. But that is a mistake. In a human, the functioning of the intellect and will is more central to flourishing than the animal functions.
This may seem discontinuous from other animals. Some will be happy with the discontinuity and some will think it’s a reductio ad absurdum of the view. But I think there is less discontinuity than seems to be the case. Think of dogs. It seems that their social life, with one another and with humans, constitutes more of their flourishing than their performance of the functions that define biological life. The social life presumably evolved because it promoted nutrition, growth and reproduction, but the social life appears more valuable. Given the likely ties between this social life and the cerebrum, it would not surprise me if dogs went with their cerebra in a cerebrum transplant.
The questions here are ones of value, and we should avoid biologism about value, even in non-human animals.
