>> Compatibilism (the thesis that free will and determinism are com-
>>patible, ie. that both can be simultaneously true) is crud. If we
>>define determinism as:
>>
>> `The theory that the state of a system at some time and the rela-
>> tions governing the time development of the system determine, un-
>> ambiguously, the state of the system at any later time. (In time
>> reversal invariant theories, the state of the system at some time
>> and the relations governing time development give the state of the
>> system at _any_ time.)'
>
>This definition presupposes that "the state of a system at some time"
>has meaning. According to relativity, the notion of simultaneity is
>dependent upon the observer. Keep in mind that the "system" of concern
>is the complete universe. Given the meaninglessness of "at some time"
>this definition is, at best, a convenient simplification, but it has no
>real substance.
What exactly is your point here? If "the state of a system at some time"
does _not_ have meaning, then determinism does not have meaning (which would
also mean that any negatively defined indeterminism does) and voluntarism
has some major obstacles cleared out of its way. Including compatibilism.
Which would make my day, but not, I think, yours.
Anyway things are by no means this simple. The success of various
deterministic theories and predictive systems that we have indicates that
we can _do_ things with the notion of "the state of a system at some time".
Furthermore if `system' is defined locally (so as not to violate
any prohibitions against superluminal influences) the definition stands just
fine, and enables the interaction of different `systems' to be
deterministically described. (The old `surface of a light cone' trick.)
Even if considered in the most atomistic and local terms, therefore,
the argument I described still stands, and it is your objection that `has no
real substance.'
>> And further is we define voluntarism (the thesis that we have `free
>>will') as:
>>
>> `The theory that a person is free with respect to same act if they
>> both can perform it and refrain from performing it.'
>
>In most cases, a person cannot "both" perform and refrain from performing,
>since one often excludes the other. Perhaps you should be using the
>word "either". But, in any case, the statement depends on the uncertain
>semantics of "can".
At the risk of being repetitve _that_ is precisely the point. `Both' is
exactly the correct word (remember I am defining the traditional version of
a doctrine, not defending it) since that makes clear the presence of
multiple possible outcomes. One clearly _must_ exclude the other, otherwise
there would be only one future, and hence no `decision' or `possibility.'
Also what I offer is a _definition_ not a `statement.' It does not `depend'
on any `uncertain sematics' at all. It does involve a committment to
one possible version of the semantics of `can', and the question as to
whether the definition describes a possible feature of the world depends
upon the tenability of that committment, which is not a matter which I in
any way deny.
>> The question, therefore, is _which_ of the two is true.
>
>This insistence on either/or, this belief in the existence of some
>absolute truth, is at the heart of your problem. There is no reason,
>other than religious belief, to suppose that the real world works this
>way. Rather than asking for the absolute truth, you should be asking
>about which is a useful interpretation of the available evidence.
>Compatiblism maintains that determinism and free will are both useful
>and compatible interpretations.
Wow! This final paragraph is so mind boggling that all I can do is ask a few questions and hope for subsequent illumination. I can identify no `point' to which I can be expected to reply/respond.
(1) Please tell me _which_ religious belief you are thinking of (or do you
maintain that they all involve some kind of `principle of non-contradiction',
which is certainly not my experience.)
(2) I want to have lunch. I have x$ there are two different kinds of food
available at the canteen, each of which costs x$. The question, therefore,
is _which_ of the two I can buy. What has this to do with religion? I
think (in my fundamentalist mania) that when two courses of action are
mutually exclusive, that only _one_ can be followed, that when two
propositions are mutually exclusive that at most _one_ can be true. To
quote _Dire Straits_:
`Two men say they're Jesus:-
_One_ of them must be wrong.'
- `Industrial Disease' from _Love over Gold_.
What is your objection?
(3) `Useful' for _what_? You mention `useful' twice.
(4) What is the `evidence' if not the effects of the way the world _really_
is? What is an `interpretation' of that evidence if not an attempt to make
sense of it in a way (pending your explanation of `useful') the sucess of
which is related to the accuracy of the fit with the way the world is?
(5) Following from (4) what is a model which _does_ fit properly if not the
