The word 'law' has a rather subtle double-meaning.
I will split it into the law-qua-theory and the 
law-qua-governing-principle.
A law-qua-theroy is one scientist's formulation of the
way a general class of events is interelated,
such as Newton's (as opposed to Einstien's) law
of gravity. A law-qua-governing-principle
refers to an out-there
aspect of reality, which laws-qua-theory attempt
to encapsulate. Laws-qua-governing-principle
underpin the accuracy of the law-qua-theory in 
predicting future events.
The law-qua-theory is analogous to the map,
the law-qua-governing-principle to the territory.

It is common to think of laws-qua-governing-principle
as having a determining effect, as 
requiring that, given a certain set of physical
circumstances, only one outcome is possible.
However a law-qua-governing-principle can govern
without determinining, by stipulating that a
range of outcomes is possible , and anything else
impossible. This is rather like the rules of chess wich
stipulate only certain moves as permissible, but do
not constrain the player into having only one permissible
move (it would not be much of a game if they did!).
It is also like the laws of a free society which tell
citizens what they must not do, but do not stipulate what they must.
The above is not merely speculative, either: if quantum mechanics
is as correct as it seems to be, the fundamental 'laws' of the
universe are of a governing-but-not-determining nature.
If they are, this does not, as is often mistakenly supposed,
undermine the predictive abilities of physical science, 
since it is still possible to confirm theories
by probablistic, statistical methods.

When causal determinists are not being simply dogmatic,
they appeal to science to demonstrate that the universe
is governed by laws. Such laws cannot be laws-as-theory,
mere maps, since maps do not guarantee that the future is fixed.
They must be laws-as-governing-principles, and *determining*
ones at that. This means they are faced with two problems:
that of showing that laws-as-governing-principles are constraining
to the point of being determining, despite what quantum 
mechanics says; and that of explaing what kind of entity, 
ontologically speaking, they actually are.
They are surely not spatio-temporal entities composed of 
matter-energy; the law of gravity is not itself some kind
of material body floating about in space. Thus, determinists must
be commited to a belief in immaterial non-spatio termporal entities
of some kind, which is rather unfortunate for them, since suspicion
about such kinds of entities often underpins their scepticism about
the volitional powers of the mind. 


Peter D. Jones 28/5/02. (24/8/04).