6. Conservation laws and closure
One purported strong indication against mind-body or mental-physical dualism is that the physical world appears to be causally closed. The total of energy and total momentum appear to be conserved whenever they have been measured in modern physics. There does not seem to be any room for minds to make a difference to evolution of the physical world. We should first note, with Meixner , that there is little or no experimental evidence to prove this within living bodies and especially within brains. The universal application of conservation laws is an assumption of the physical sciences, not a result as it is commonly presented. Arguments for causal closure have turned out to depend on some assumption that is almost identical to the result to be proved  .
Suppose that physicists found that energy and momentum were not conserved in some instances. How would they react? First, they would note that the laws apply only to isolated systems, so they would examine whether the object really was isolated or not, and whether they should look for something further (like a hidden planet) that was producing the effects. Secondly, they would generalize the conservation laws so the new law was satisfied but not the old one. It used to be thought, for example, that total mass and total energy were separately conserved, but, after many subatomic experiments showing the annihilation and creation of massive particles, those separate laws were quietly dropped in favor of a general law of conservation of mass-energy in combination. If, therefore, the non-conservation of energy and/or momentum were found in certain biological or psychological processes, science as we know it would not collapse. Either the influence from other kinds of beings would be ascertained, or a further generalization of the conservation laws would be sought. The only novelty in the proposals here, is that these ‘other kinds of beings’ would not be ‘physical’ in the traditional way.
 U. Meixner, "Physicalism, Dualism and Intellectual Honesty," Dualism Review, vol. 1, no. 1, pp. 1-20, 2005.
 U. Mohrhoff, "The Physics of Interactionism," J. Consciousness Studies, vol. 6, pp. 165-184, 1999.
 W. Hasker, "How Not to be Reductivist," PCID, vol. 2.3.5, pp. 1-16, 2003.
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