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Connecting causal closure and its backing in a non-reductive manner

Chapter 2: Kim’s causal exclusion argument against non-reductivism

2.2 A summary of Kim’s exclusion argument

2.3.3 The empirical/inductive argument for closure

2.3.3.2 Connecting causal closure and its backing in a non-reductive manner

The other way of matching the language of the conservation and no energy premises with the conclusion is to include a few further premises concerning the possible ways physical systems can be affected by anything. This is how Gibb (2010) reformulated and supplemented the argument. The inclusion of further premises is necessary if one wants to make the inference from the premises to the conclusion valid.

First, it is plausible that a physical system can be changed by physical energy or momentum transference from without. Note two things: according to the conservation

premise this transference can only start from without the affected system, from a more extended system and if the whole physical realm is one conservative system then from without this system no physical energy flow is possible. Even if there is something outside the physical realm that realm cannot contribute physical energy to the physical realm as that would violate the conservativeness of physical energies. In other words, nothing in the physical realm/system happens because something outside of it changes the amount of energy or momentum inside the realm.

However, there is a second plausible way a physical system can be changed. The energy and/or momentum distribution of the system can be changed from without. Note that redistribution is a good general description for the normal evolution of any closed physical system that behaves in line with the conservation of energy principle and basic dynamical laws. In all such systems energy and momentum gets redistributed as a result of the system’s evolution in time. But normal evolution should not count as an interesting change introduced into the distribution of energy or momentum as usually when talking about vital or mental causation we are talking about interventions originating from without the physical system causing redistribution. So, the third premise to include says that there are (at least) two ways to affect a physical system:

AFFECTABILITY: The only ways that something could affect a physical system is by (1) affecting the amount of energy or momentum within it or by (2) redistributing the amount of energy or momentum within it.

We still owe an answer to the question of what kind of things could bring about changes in the distribution of energy or momentum. This question should be treated with much caution. It is plausible that it is brought about, caused by the transference of energy or

momentum. According to the conservation principle, in that case, the impulse should come from without the physical system in question. If our system is the physical realm as a whole, then the existence of such impulses is inconsistent with the conservation premise. If the system in question is a subsystem of the physical realm then this could happen in accordance with the conservation premise. So, it seems that what the fourth premise should say is this:

REDISTRIBUTABILITY: Redistribution of energy and momentum cannot be brought about without supplying energy or momentum.

Accepting these four premises provides us with an argument for the causal closure of the physical that appears to be valid. However, following Gibb (2010), I don’t want to commit myself to the sufficiency of this argument, the only real commitment I would like to make is that these four premises are required for the argument from conservation to work.

CONSERVATION: Every physical system is conservative, or it is part of a larger conservative system.

NO-ENERGY: There is no non-physical energy

AFFECTABILITY: The only way that something non-physical could affect the physical is by (1) affecting the amount of energy or momentum within it or (2) redistributing the amount of energy or momentum within it.

REDISTRIBUTABILITY: Redistribution of energy and momentum cannot be brought about without supplying energy or momentum.

--- CLOSURE: Therefore, the causal closure of the physical is true

Now that we have a compact argument that seems to work let’s turn to the examination of the new premises. The present formulation of the redistribution premise would be supported by the acceptance of a physical theory of causation, but as we already saw that would make the conservation premise redundant, so we need independent support. It is important to mark that the premise concerning redistribution says something dubious. I have already mentioned that redistribution can result from the normal evolution of a closed physical system without the introduction of extra energy, so the premise seems to say more than it should, it should allow for further possibilities.

In most possible closed physical systems, a kind of uninteresting or default redistribution occurs without impulses from the outside. This process is driven by basic physical laws. While the closed system runs its course, it evolves from an initial state towards others states or an end state. This evolution of the system can be expressed as a pattern of redistributions of energy and momentum in time where earlier distributions determine later distributions or states. There is exchange of relevant properties/quantities between components of the system, but there is no change in total amounts. This default redistribution does not require energy or momentum from the outside it is simply a reflection of the internal evolution of the physical system in question.