A more accurate title of this blog entry would be, ‘Property Dualism is (or may as well be) Substance Dualism unless you go for Panpsychism and only for the purpose of assessing theories against Ockham’s Razor’.
First, Ockham’s Razor is more compelling in the form that, one should not multiply types of entities beyond necessity. We can imagine many examples of interactions between particles in which the behaviour of one token particle is explained in our best physics by a collision with two other token particles. It is obviously better to accept this explanation than to propose a new type of particle that would explain the interaction as occurring only between two token particles.
Second, unless crazy Panpsychism is accepted, property dualism leads to two types of entities (purely physical and physical/mental hybrid entities) instead of the one type (purely physical) of physicalism. Substance dualism similarly leads to two types of entities (purely physical and purely mental entities).
So, property dualism is no better off, as a parsimonious theory, than substance dualism, except in the much weaker sense of not multiplying token entities… unless one is a Panpsychist… and crazy.
I don’t think this is right anymore. It’s multiplying tokens that should be avoided.
If I were forced to choose I would prefer Descartes’ original Res Cogitans, the unextended point from which observation is possible, to the idea of a mystical companion to ordinary matter. Descartes’ supernatural soul can enjoy the geometry of experience whereas the ghostly property that is the special property of “property dualism” has all the same problems of regression and being impossibly instantaneously present as the ‘matter’ that is so loved by materialists.
How can Ockham’s razor apply to two such different approaches? Substance dualism attempts to explain our experience whereas property dualism seems to be largely an imaginary answer to the shortcomings of materialism such as the difficulty in identifying voltage changes in C fibres with the feeling called pain.
If I were not forced to choose I would choose neither.