Interactionist Dualism Defended II

Koksvik is especially concerned with the argument that interactionist dualism can't work because for it to do so would violation the law of the conservation of energy (supplemented perhaps by the law of the conservation of angular momentum).

The idea behind this argument is that IF my thoughts cause me to do something I wouldn't otherwise do, then they must do so by exerting energy. Energy after all is that which does work, that which which moves matter around.

Thus, if interactionism is true, energy is leaking into the phenomenal world from some trans-phenomenal source. Surely this would violate that law.

If we're going to say, "so much the worse for the law then!" we can do so. Laws sometimes have to be modified and sometimes abandoned. Still, these leaks of energy into the phenomenal world should be in principle detectable, and anyone arguing for interaction should be able to make a case that they exist, that the law is violated, before arguing for a view of the world that requires abandoning that law.

So runs the argument. What does Koksvik say about it?

He cites and elaborates on a claim by Karl Popper, in The Self and Its Brain (1977): "One possibility that would suit us extremely well would be that the law of the conservation of energy would turn out to be valid only statistically. If this is the case, it might be that we have to wait for a physical fluctuation of energy before World 2 [the mental world] can act upon World I [the physical world], and the timespan in which we prepare for the 'free-will movement of the finger' may easily be enough to allow for such fluctuations to occur."

The wording in the brackets, intended to paraphrase Popper, is Koksvik's, not mine.

Koksvik then distinguishes three different interpretations of Popper's words. The most important of the three is this one, that C of E is both valid and exact, energy is exactly conserved over time, but deviances can occur at any given instance.

"The increase in total energy that this movement [of the finger] may otherwise have caused would then not obtain, given the opposite fluctuation that was already manifest," writes Koksvik.

Thus, the C of E as properly understood is not violated. Further, the brief apparent violations (or the actual violations of an overly strict reading of the law) have not been detected due to a levelling out effect inherent in how the interactions work -- the non-detection should not surprise us.