Dear Nina, Jim and Rett,
Thanks for these details, which show how carefully we have to
consider before concluding the Theravada tradition is wrong.
A while back someone wrote to me saying that they couldn't accept
the commentaries because these said the heart was the physical basis
for mind. I include my reply below:

_____

> On the other hand, Buddaghosa CONFIRMS in Visuddimagga that the
> seat of the
> Mind is Heart. Now we know, this cannot be possible, through
> lots of
> knowledge we have gained on the functions of the heart and the
> brain and the
> associated central nervous system. If the heart is the seat of
> the
> consciousness, what happens during open heart surgeries where
> the heart is
> kept inactive for hours before activating by an electric shock
> at the end of
> the operation.
>
> On the other hand, what consciousness a person will have who
> receives a new
> heart from another dead person?
>

__________________________________________
Dear friend,

The visuddhimagga (viii, 111)says about hadaya-vatthu (heart
basis):
they describe the heart and then note that inside the heart
"there is hollow the size of a punnaga seeds bed where half a
pastata measure of blood is kept, with which as their support
the mind element and mind-consciousness element occur."
Note that it is not the heart itself that is the hadaya-vatthu
NOR is it the blood inside the heart but rather as the
Paramatthamanjusa (see vis.xiii note 5 ) says "the heart basis
occurs with this blood as its support".
You see the actual hadaya-vatthu is incredibly sublime - in
scientific measure it wouldn't even amount to a tiny fraction of
a gram. It might even be so refined as to be unmeasuarable by
scientific instruments.
This applies also to the other sense organs (pasada rupa). The
Atthasalini remarks that the very purpose of using the term
pasada is to dismiss the popular misconception of what we think
an eye or an ear is. (see karunadasa p45)The actual sensitive
matter in the eye and ear is very refined. If someone dies then
the ear-sense and eye sense (sotapasada and cakkhu-pasada ) are
immediately no longer produced (they are produced by kamma only)
yet one would not notice much outward change looking at the eye
and ear(at least for the first few minutes before decomposition
sets in). The same applies to the heart - the blood in the heart
would have the same volume after death and yet the hadaya-vatthu
is no longer present.


I think you accept that consciousness arises soon after
conception. The fetus at that stage is so tiny as to be
invisible to all but the most trained eye (if even that large).
yet consciousness is arising and passing away dependent on some
matter(rupa) somewhere. There is certainly no brain yet but
according to the commentaries the heart basis (hadaya-vattu )
,that extremely subtle, rupa is already present - conditioned by
kamma. This shows how extraordinarily subtle this type of rupa
is.
There is more that I could write about this. However, I think
one can see how heart transplants etc. make no difference to the
arising and passing of this subtle conditioned rupa.
.
What does the brain do then? It does something, it is like
wiring center needed for functioning of the body mind - Sure if
you pull out a few wires , just as with a computer, things
aren't going to work so well. One will always be confused about
these problems if one thinks in stories about people and hearts
and medicine and brain- Even detailed scientific explanations
cannot approach the nature of the true reality of the evanescent
conditioned phenomena we call life. There are only rupas and
namas arising and passing away, and just as with the tipitaka
the commentaries lead us to see this truth .
robert