“you are your body, you persist as your body persist”
Body Thesis: People are their bodies
Body Criterion: x = y iff x’s body = y’sbody
Objections to Body Criterion & How Thompson Rebutted
“Blue is gone. But his body its still here, which means blue isn’t identical with his
▯Blue is here. His body is here. He’s just dead. There’re dead people. People who
die just become dead people at the time of their deaths.
Case 1: scena io
Transplants brain in B’s body into R’s body & destroys B’s body
▯I’m Brown. I want what I wanted…
Intuitively, many would say:
but survivor’s body isn’t B’s body, its R’s body ▯ R’s body with B’s brain
Is this right? If so, body criterion must be rejected, thus body thesis.
Case 2: reasoning over #1
When B’s brain transplants into R’s body, a drug will reconfigure it to R’s psychology
In #1, the brain is irrelevant. We think survivor= Brown not due to the brain
transplant, but the presupposition that the brain carries the psychology.
In #2, the transplanted brain doesn’t carry Brown’s psychology ▯ we aren’t
inclined to think that the survivor is Brown.
▯brain isn’t driving bswitching belief; rather its movement of psychology.
R’s psychology reconfigured to match with B’s & B’s body destroyed.
▯I am Brown.
Many would think survivor= Brown b/c they think transplanting B’s psychology
is necessary and sufficient for B to switch body. Same as #1
Is this right? If so, body criterion is rejected, so its body theory. 2
Thompson’s Reply to Body Switching
Alternative to Body Criterion
Mental Criterion: x = y iff x’s psychology is connected with y’s in the right way
If one has the same psychology of Queen Victoria. Is that person Q. Vic?
No ▯mental criterion is rejected.
Case 4: lead to think bodyswitching is not possible
Reprogram D&R to have same psychology as B before he died
▯D&R are Brown.
According to mental criterion, D&R are both Brown, but they can’t both be
Brown cause they aren’t the same person, they’re distinct entities
▯MC is rejected
Since D&R can’t be Brown, B hasn’t survived. So if B hasn’t survived in R in this
case, he couldn’t have survived in #3 either.
Thompson’s Argument to Bodyswitching
1. If MC is true, then x=y iff x’s mind is appropriately connected to y’s mind [def of
2. B’s mind is appropriately connected to both postopind of R B postopind of D B
3. If MC is true, then Brown = both the person associated with R & the
person associated with postopB 
4. If Brown= both of these people, then these people are identical with one another.
[Transitivity of identity]
5. If MC is true, then the person associated withpostoB = the person associated
with postoB 34]
6. The person associated with postoB ≠