The Brain Transplant Argument

[Philo]

Animalism is the thesis that each of us is numerically identical to a human animal (e.g., you are identical to the human animal reading this post right now), and that each of us persists just in case the biological functions that sustain the life of the human animal we are identical to continue. Since the persistence conditions for animals in general are biological and not psychological, according to animalism the continuation of our mental lives is irrelevant to our persistence. This is a minority view among philosophers writing about personal identity.

The following argument, called the Brain Transplant Argument (BTA), has been advanced against animalism (its reconstruction here is taken from Paul Snowdon, "Personal Identity and Brain Transplants"):

(1) It is not absolutely impossible that our brains should be transplanted into new receptacles while retaining their intrinsic functions. (The intrinsic functions are the processes that characteristically occur in the brain, and which are assumed to sustain a mentally endowed subject.)

(2) Amongst the brain’s intrinsic functions is that of sustaining a subject with thoughts, apparent memories, beliefs, (etc.), and so such a rehoused and functioning brain will sustain a subject of experience who has psychological links to the donor subject.

(3) The total system, of which the rehoused brain is a functioning part, is not the self-same animal which donated it.

(4) The resulting subject sustained by (or realized by) this system would be the same subject (or person) which that brain previously sustained.

Do you think that BTA shows that animalism is false?

[Phil153]

Man that's some bad prose. Does the writer speak English? Does he have a tumor?

Clarifications needed: "numerically identical"
"just in case"
"the human animal we are identical"?
"persistence conditions"
"persistence"

They seem to be playing with the definition of persistence - basically saying that if the majority of an organism's cell continues to survive and be functional, then the "person" does too. But the leading paragraphs don't define their terms well enough to be able to critique the theory.

[ QUOTE ]
Do you think that BTA shows that animalism is false?

[/ QUOTE ]
No. The whole question is so poorly written and defined that you can't respond to it.

[Philo]

[ QUOTE ]
Man that's some bad prose. Does the writer speak English? Does he have a tumor?

Clarifications needed: "numerically identical"
"just in case"
"the human animal we are identical"?
"persistence conditions"
"persistence"

They seem to be playing with the definition of persistence - basically saying that if the majority of an organism's cell continues to survive and be functional, then the "person" does too. But the leading paragraphs don't define their terms well enough to be able to critique the theory.

[ QUOTE ]
Do you think that BTA shows that animalism is false?

[/ QUOTE ]
No. The whole question is so poorly written and defined that you can't respond to it.

[/ QUOTE ]

Good questions. To clarify:

"numerically identical": If a and b are numerically identical then a and b are one and the same thing. For example, Mark Twain and Samuel Clemens are numerically identical.

"just in case" is shorthand for the biconditional "if and only if," which expresses a relationship between a and b in terms of necessary and sufficient conditions.

Thinking of a and b as events now, "if a, then b" means a's happening is sufficient for b's happening, and b's happening is necessary for a's happening.

So, "a if and only if b" (or "a just in case b") means that if a happens then b will happen, and if b happens then a will happen.

"persistence": to persist is to continue to exist over time. If an object O existed yesterday and also exists today, then that object O has persisted from yesterday to today (and hence the object O today is numerically identical to the object O of yesterday). The "problem of personal identity" is the problem of figuring out what our persistence conditions are, i.e., what constitutes our continued existence over time as the numerically same entity.

So, to say that I persist (or continue to exist) 'just in case' the human animal that I am identical to continues to exist is to say that I will continue to exist if that human animal continues to exist, and that if that human animal continues to exist then so will I.

Since the continued of existence of biological organisms in general does not seem to require psychological continuity (or even the continuation of psychological capacities), the animalist claims that my persistence does not require the continuation of my psychological life. BTA tries to show that this claim is false.

[furyshade]

half the time in this forum i can't tell if what i'm reading is too complex for me to understand or just too poorly written

[Kaj]

If you take out the processor of your computer, is the rest of your computer no longer still your computer? If you put that processor in another computer is it now the previous computer or a different computer? Who cares what you call it. It's one organ in a new body, and the old organs and the rest are in the old body. The whole "what is 'me' and what isn't 'me'" question is the busywork of shallow philosophers.

[Phil153]

Thanks for the answers, it's clearer now. But the theory is still horribly confused and not at all stated clearly. To summarize:

1. "We" are identical to our biology (nihilism).
2. Persistence of an organism depends on whether its biological functions are sustained.
3. Therefore, our mental life has nothing to do with our persistence

The argument of Animalism basically begs the question by denying the existence of separate thing called "mental life" or identity, reducing everything to biology. It's also ill defined by not defining organism properly. Is it the majority of cells (how does that work for a fat person undergoing liposuction?) Is it certain cells?

Basically, animalism as a theory does not exist because it doesn't define itself.

So the only thing the "brain transplant" scenario shows is "organism" in animalism is poorly defined. It certainly doesn't refute it. You could define a version of animalism in which it's claimed that we are just the biology of our brains, and the rest of our body is just a support function. This would retain the core elements of the theory and get around the brain transplant refutation.

[Philo]

[ QUOTE ]
Thanks for the answers, it's clearer now. But the theory is still horribly confused and not at all stated clearly. To summarize:

1. "We" are identical to our biology (nihilism).
2. Persistence of an organism depends on whether its biological functions are sustained.
3. Therefore, our mental life has nothing to do with our persistence

The argument of Animalism basically begs the question by denying the existence of separate thing called "mental life" or identity, reducing everything to biology. It's also ill defined by not defining organism properly. Is it the majority of cells (how does that work for a fat person undergoing liposuction?) Is it certain cells?

Basically, animalism as a theory does not exist because it doesn't define itself.

So the only thing the "brain transplant" scenario shows is "organism" in animalism is poorly defined. It certainly doesn't refute it.

[/ QUOTE ]

I've only stated the central theses of animalism. I haven't given a full explication of the view nor have I given any reasons for believing it.

Thus I don't see how you can conclude from my post that animalism begs the question, since I've told you nothing about what arguments have been advanced in its favor, or that the theory doesn't really exist because it doesn't define itself, since I haven't given you a full explication of the theory.

Animalism doesn't deny the existence of the mental lives of human beings, it simply denies that the mental lives of human beings figure into the persistence conditions of human beings.

Animalism defers to biological science when defining what is essential to preserving the life of a biological organism.

Your last suggestion is interesting, because some animalists distinguish between whole-brain transplants, which include transplantation of the brain stem, and cerebrum-only transplants, which do not. Since the brain stem controls respiration, heartbeat, blood pressure, and digestion, and is also vital to basic attention, auditory and visual reflexes, and consciousness, the neurological functions of the brain stem are considered essential to sustaining the life of an animal.

The central theses of animalism are thus consistent with the "brain transplant intuition" (roughly, the intuition that I go where my brain goes), at least in the case of whole-brain transplants.

[Alex-db]

[ QUOTE ]
If you take out the processor of your computer, is the rest of your computer no longer still your computer? If you put that processor in another computer is it now the previous computer or a different computer? Who cares what you call it. It's one organ in a new body, and the old organs and the rest are in the old body. The whole "what is 'me' and what isn't 'me'" question is the busywork of shallow philosophers.

[/ QUOTE ]

Its more like replacing the processor, RAM, hardrive, graphics card, cache etc. - clearly a new pc in your analogy. Or if the old parts are put in a different case, clearly back to the original pc.

[tame_deuces]

The brain does not work separately from your body. Physically it is connected too it through the nervous system. And the body differectly interacts and affects the brain's function (and vice versa) through glands, sensation, perception too name only a few. So if you switch bodies you would be different. We could assume some similar sense of cognition is still there but simply from physical function alone your brain would operate differently from before.

[kerowo]

Does all philosophical discussion sound like wankery or just this one?

IF sci-fi brain transplants are possible
AND IF a person's conscious resides entirely in the brain
THEN that person would inhabit whatever body the brain was in

What is the refutation of this? That the new body wouldn't be the same person because they are in a new body? Even though the new body would have the same memories, personality, and beliefs as the original body? That's a tough argument to make.