Reduction and Elimination in Philosophy and the Sciences

determination thesis; it fails as a refutation of that thesis.
Physical determination is a very strong negative thesis: it
claims that there do not exist any two possible worlds that
match with respect to the non-nomic details but have different
laws of nature. So one way to argue against it is
simply to try to describe a pair of possible worlds that constitute
a counter example. This strategy is employed by
Michael Tooley (1977, pp.669-672) and also is used in
Carroll (1990). I will consider the so called mirror argument
against Physical Determination here.
The argument begins with a possible world, U1, that
consists of five X-particles and five Y-fields. When each
particle enters its Y-field it acquires spin up. All of the
particles move in a straight line for all of eternity. But close
to the route of one particle there is a mirror on a swivel.
(Call this particle “particle b”). The mirror is in such a
position (call it “position c”) that it does not get in the way
of the trajectory of particle b. It seems plausible that the
following is a law in U1:
(L) All X-particles subject to Y-fields have spin up.
Now consider U2, a world that is just like U1 except that
particle b does not acquire spin up upon entering the
Y-field. Hence, L is not true at U2. Now, U1 and U2 do not
pose a problem for the MRL view because the worlds differ
in their particular matters of fact. The problem stems from
considering what would have occurred in each of the
worlds had the mirror been in position d, stopping particle
b from entering the field. Consider the nearest possible
world to U1, U1*; here, it seems reasonable to say that L is
a law because the worlds only differ in that the mirror
blocks the particle from entering the field. Now consider
the closest world to U2, U2*, where the mirror blocks the
particle. It seems that although L is true in U2* it is an accident
because had the mirror not been in the way L would
be false. U1* and U2* are identical in their particular matters
of fact; yet it seems that L is a law at U1* but not at
U2*. Hence, laws do not supervene on particular matters
of fact. Therefore, Physical determination is false.
I guess there is one reasonable response to the
Mirror Argument given by Humeans. The Humean just
retorts that any counterintuitiveness is not a strike against
Physical determination, for such intuitions presuppose an
anti-determinationist vantage point. Helen Beebee offers
this sort of response to the Mirror Argument. She writes:
As a friend of supervenience, I have no desire to
find a way of grounding the ‘fact’ that L is a law in
U1*, but not in U2*, since I think L is a law in U2*
and not an accident. This commits me to the apparently
unacceptable claim that the position of the mir
Assessing Humean Supervenience — Amir Karbasizadeh
ror in U2 affects what the laws of nature are, since I
am committed to the truth of the counterfactual ‘if
the mirror had been in position d, L would have
been a law.’ But I truly see no harm in that … As I
said earlier, part of the Humean creed is that laws of
nature depend on particular matters of fact and not
the other way around; it is no surprise to the
Humean, then, that by counterfactually supposing
the particular matters of fact to be different one
might easily change what the laws of nature are too.
The intuition that’s really doing the work in this
counterexample, then, is the intuition that laws are
not purely descriptive … But to describe the example
in those terms is not to describe it in neutral
terms but to describe it in terms which explicitly presuppose
an anti-Humean starting point …
At first blush at least, it is clear why the Humean would feel
compelled to assert this. After all, there is a sense in which
they are being told that their view is false simply because it
doesn’t say the laws govern. The Humean thinks the anti-
Humean position is in the grip of an intuition which is ultimately
incorrect.
7. Conclusion
I have considered Humean Supervenience and its two
components and their plausibility. I conclude that the first
component of Humean Supervenience namely Separability
is untenable. However, I see no reason not to believe in
the second component of it.
Literature
Albert, D. Z., 1992, Quantum Mechanics and Experience. Harvard
University Press.
Beebee, Helen., 2000, “The Non-Governing Conception of Laws of
Nature”, Philosophy and Phenomenological Research, LXI, No.3.
Carroll, John., 1994,.Laws of Nature Cambridge: Cambridge University
Press.
Lewis, D., 1973, Counterfactuals, Cambridge: Harvard University
Press.
-----------, 1983, “New Work for a Theory of Universals, Australasian
Journal of Philosophy, 61: 343-377.
-----------, 1986, Philosophical Papers, Volume II, New York: Oxford
University Press.
Roberts, John., 1998. “Lewis, Carroll and Seeing Through the
Looking Glass” Australasian Journal of Philosophy 76(3).
Tooley, M.,1977, “The Nature of Law”, Canadian Journal of Philosophy,
7: 667-98
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