Online research in philosophy

Nearly 30 years have passed since Donald Davidson first presented his ar- gument against the possibility of psychophysical laws in “Mental Events”. The argument applies to intentional rather than phenomenal properties, so whenever I refer to mental properties and to psychophysical laws it should be understood that I mean intentional properties and laws relating them to physical properties. No consensus has emerged over what the argument actually is, and the subsequent versions of it presented by Davidson show significant differences. But many have been inclined to agree with the spirit of the argument and with its conclusion.

The paper discusses Ted Honderich's ?Hypothesis of Psychoneural Correlation?, one of the three fundamental ?hypotheses? of his Theory of Determinism. This doctrine holds that there is a pervasive system of psychoneural laws connecting every mental event with a neural correlate. Various questions are raised and discussed concerning the formulation of the thesis, Honderich's concepts of ?mental? and ?physical?, and the possible grounds for accepting the thesis. Finally, Honderich's response to Donald Davidson's well?known arguments for psychophysical anomalism is discussed.

The paper argues against systematic overdetermination being an acceptable solution to the problem of mental causation within a Humean counterfactual theory of causation. The truth-makers of the counterfactuals in question include laws of nature, and there are laws that support physical to physical counterfactuals, but no laws in the same sense that support mental to physical counterfactuals.

The objective probability of every physical event is fixed by prior physical events and laws alone. (This thesis is sometimes expressed in terms of explanation: In tracing the causal history of any physical event, one need not advert to any non-physical events or laws. To the extent that there is any explanation available for a physical event, there is a complete explanation available couched entirely in physical vocabulary. We prefer the probability formulation, as it should be acceptable to any physicalist, though some reject the explanation formulation.) (3) Causal Exclusion.

The following framework of theses, roughly hewn, shapes contemporary discussion of the problem of mental causation: (1) Non-Identity of the Mental and the Physical Mental properties and states cannot be identified with specific physical properties and states. (2) Causal Closure (Completeness) of the Physical The objective probability of every physical event is fixed by prior physical events and laws alone. (This thesis is sometimes expressed in terms of explanation: In tracing the causal history of any physical event, one need not advert to any non-physical events or laws. To the extent that there is any explanation available for a physical event, there is a complete explanation available couched entirely in physical vocabulary. We prefer the probability formulation, as it should be acceptable to any physicalist, though some reject the explanation formulation.) (3) Causal Exclusion There is at most one complete and wholly independent explanation for any given event or sequence of events.

In common with other forms of nonreductive materialism, emergent materialism of this sort is accused of trying to have its cake and eat it. Ontological physicalism, it is said, necessarily implies reductionism which rules out the idea that there are irreducible emergent mental properties and laws. For according to such physicalism, everything is composed of physical constituents whose behaviour is governed by the laws of physics and mechanics. It follows that, in theory at least, every particular mental process is describable and explainable in purely physical terms, without recourse to mental descriptions. Description in terms of emergent properties and laws seems superfluous. Nothing save the complexity of the task prevents us from describing and explaining everything that exists or happens in purely physical terms.

The paper defends Humean approaches to autonomous mental causation against recent attacks in the literature. One important criticism launched at Humean approaches says that the truth-makers of the counterfactuals in question include laws of nature, and there are laws that support physical-to-physical counterfactuals, but no laws in the same sense that support mental-to-physical counterfactuals. This paper argues that special science causal laws and physical causal laws cannot be distinguished in terms of degrees of strictness. It follows that mental-to-physical counterfactuals are supported—or not supported—by laws in just the same way as are physical-to-physical counterfactuals.

In our everyday discourse, we distinguish without fail between minds and bodies or between the mental and the physical. Yet, in philosophy there is a tendency to get rid of this divide. Roughly, the naturalist wants to reduce or to identify the mental with the physical in order to provide a unified basis for scientific research. The idealist, in contrast, sticks to the mental as a precondition of grasping the physical. The physical then tends to turn into mere mental representations. These attempts to overcome the divide, however, are not very promising. While the first tries to assimilate the mental to the physical, the second takes the opposite approach with the result that either the mental or the physical goes by the board. Fortunately, there is a third option: the realist maintains that the mental exists along with the physical.