tmoody@sjuvax.UUCP (T. Moody) (08/05/85)
(p --> q)
I posted a recent article entitled "Indeterminism." I meant for the
title to be "Soft Indeterminism" which, in case anybody read it, would
make more sense.
Rich Rosen has asked whether there is any evidence of acausal activity
in the human brain. Well, the diameter of a synaptic vesicle is about
400 angstroms. The brain activity in which we are interested is
electron transfer across synaptic gaps, via these vesicles. At this
scale, this activity is subject to quantum indeterminacy (if you
prefer, neural activity has a significant Brownian component). Thus,
even though the relatively large scale, protein-type interactions
within a single neuron are subject to classical causation, the
interactions between neurons are not *entirely* explainable in
classical terms.
It seems to me that there are two possible responses to this news:
(1) One may conclude that the claim that the human brain is a
deterministic system is just false. All further claims purported to
follow from this claim are then unsupported.
(2) One may argue that quantum acausality is merely apparent; there
are deeper deterministic causal mechanisms that physics just doesn't
know about yet.
Claim (2) is often called the "hidden variables" interpretation of QM.
Needless to say, this issue is somewhat distant from the original free
will debate. Still, the disputants need to recognize that this is a
significant factor, one that cannot be brushed off (some of them do
recognize this).
As I pointed out in "Indeterminism", claim (1) does not win the day
for the libertarian (metaphysical, not political, okay?), but it does
contradict hard determinism. Therefore, anyone who wants to stick
with hard determinism MUST digress and show that quantum indeterminism
is merely apparent (i.e., defend "hidden variables").
Personally, I think that the evidence against the "hidden variables"
interpretation -- insofar as I am able to understand it -- is
approaching conclusiveness. I can recommend an excellent book (by a
physicist) on this subject: *In Search of Reality* by Bernard
d'Espagnat.
If anybody out there wants to digress in this direction, let's do it.
Todd Moody {allegra|astrovax|bpa|burdvax}!sjuvax!tmoody
Philosophy Department
St. Joseph's U.
Philadelphia, PA 19131 "Big Bucks in Philosophy!"