and the Problem of Strong Closure
by Sophie Gibb
Closure is the central premise in one of
the best arguments for physicalism—the
argument from causal overdetermination.
According to Closure, at every time at which
a physical event has a sufficient cause, it has
a sufficient physical cause. This principle is
standardly defended by appealing to the fact
that it enjoys empirical support from numerous
confirming cases (and no disconfirming
cases) in physics. However, in recent literature
on mental causation, attempts have been
made to provide a stronger argument for it.
This essay argues that, insofar as these attempts
are successful, they actually establish
a far stronger closure principle. Worryingly,
the acceptance of this stronger principle
presents a new problem for the most popular
form of physicalism, that of nonreductive
physicalism. The problem shall be referred
to as the 'Problem of Strong Closure.'