The Soul of 'Shropshire'

Paul Grice writes:

"When I was an Oxford undergraduate, there was a contemporary of mine whose
name I cannot remember; it was the name of some English county, so let us
call him "Shropshire". His career at Oxford did not last very long; an
unsurprising fact -- given that, at an early philosophical tutorial, he
claimed that the immortality of the soul is proved by the fact that, if you
cut off a chicken's head, the chicken will run round the yard for a quarter
of an hour before dropping. [...] I have an 'expansion' of Shropshire's
argument. It runs as follows."

"If the soul is not dependent on the body, it is immortal.
If the soul si dependent on the body, it is dependent on that part of the
body in which it is located.
If the soul is located in the body, it is located in the head.
If the chicken's soul were located in its head, the chicken's soul would be
destroyed if the head were rendered inoperative by removal from the body.
The chicken runs round the yard after head-removal.
It could do this only if animated, and controlled by its soul.
So the chicken's soul is not located is, and not dependent on, the
chicken's head.
So the chicken's soul is not dependent on the chicken's body.
So the chicken's soul is immortal.
If the chicken's soul is immortal, _a fortiori_ the human soul is immortal.
So the soul is immortal."
H. P. Grice, Aspects of Reason.
Clarendon Press, Oxford, 2001, p. 11.