Online research in philosophy

In his recent work, Dretske offers a new account of what it is for a mental state, in particular, a sensory experience, to be conscious. According to Dretske’sproposal, subject S’s experience of object O is conscious if and only if it makes S aware of O. This proposal is argued to be open to only two serious interpretations. The first takes it to mean that S’s experience of O is conscious if and only if it constitutes S’s awareness of O, whereas the second takes it to mean that S’s experience of O is conscious if and only if it causes S’s awareness of O. It is argued that neither is a plausible way to understand the nature of state consciousness, because the constitutive interpretation implausibly denies the existence of unconscious veridical experiences, whereas the causal interpretation implausibly casts S’s veridical experience of O, rather than O or a certain external event involving O, as the relevant cause of S’s awareness of O.

Minimally, causal realism (as understood here) is the view that accounts of causation in terms of mere, regular or probabilistic conjunction are unsatisfactory, and that causal phenomena are correctly associated with some form of de re necessity. Classic arguments, however, some of which date back to Sextus Empiricus and have appeared many times since, including famously in Russell, suggest that the very notion of causal realism is incoherent. In this paper I argue that if such objections seem compelling, it is only because everyday expressions concerning causal phenomena are misleading with respect to certain metaphysical details. These expressions generally make reference to the relations of events or states of affairs, but ignore or obscure the role played by causal properties. I argue that on a proposed alternative, an analysis in terms of causal processes, more refined descriptions of causal phenomena escape the charge of incoherence. Causal necessity is here located in the relations of causal properties. I distinguish this view from the recent process theories of Salmon and Dowe, which are disinterested in causal realism.

In an influential article published in 1982, Bas Van Fraassen developed an argument against causal realism on the basis of an analysis of the Einstein-Podolsky-Rosen correlations of quantum mechanics. Several philosophers of science and experts in causal inference -including some causal realists like Wesley Salmon- have accepted Van Fraassen’s argument, interpreting it as a proof that the quantum correlations cannot be given any causal model. In this paper I argue that Van Fraassen’s article can also be interpreted as a good guide to the different causal models available for the EPR correlations, and their relative virtues. These models in turn give us insight into some of the unusual features that quantum propensicies might have.

There are two broad classes of empirical theories of consciousness, which I will call the biological and the functional. The biological approach is based on empirical correlations between experience and the brain. For example, there is a great deal of evidence that the neural correlate of visual experience is activity in a set of occipetotemporal pathways, with special emphasis on the infero-temporal cortex. The functionalist approach is a successor of behaviorism, the view that mentality can be seen as tendencies to emit certain behavioral outputs given certain sensory inputs. The trouble with behaviorism is that it did not allow that mental states were causes and effects, but functionalists do allow this. They characterize consciousness in terms of its causal role: the causal influence on it from inputs and other mental states, and its causal efficacy with respect to other mental states and behavior. The central idea of functionalism is a proposal about the concept of consciousness, but scientific functionalists have filled the view in with empirical details—the idea is that a representation is conscious if it is broadcast in a global neuronal workspace. (See the article by Dehaene in Dehaene, 2001.) The functional approach says consciousness is a role, whereas the biological approach says consciousness is a realizer of that role. For example, one could take solubility to be a role—dissolving in certain circumstances—or, as with the biological view of consciousness, the physico-chemical configuration that has that role. The..

Daniel Wegner argues that our feelings of conscious will are illusory: these feelings are not causally involved in the production of action, which is rather governed by unconscious neural processes. I argue that Wegner's interpretation of neuroscientific results rests on two fallacious causal assumptions, neither of which are supported by the evidence. Each assumption involves a Cartesian disembodiment of conscious will, and it is this disembodiment that results in the appearance of causal inefficacy, rather than any interesting features of conscious will. Wegner's fallacies illustrate two take-away points to heed if making claims about the causal structure of agency.

Quantum mechanical theories of consciousness are contrasted to classical ones. A key difference is that the quantum laws are fundamentally psychophysical and provide an explanation of the causal effect of conscious effort on neural processes, while the laws of classical physics, being purely physical, cannot. The quantum approach provides causal explanations, deduced from the laws of physics, of correlations found in psychology and in neuropsychology.

Causal closure arguments against interactionist dualism are currently popular amongst physicalists. Such an argument appeals to some principles of the causal closure of the physical, together with certain other premises, to conclude that at least some mental events are identical with physical events. However, it is crucial to the success of any such argument that the physical causal closure principle to which it appeals is neither too strong nor too weak by certain standards. In this paper, it is argued that various forms of naturalistic dualism, of an emergentist character, are consistent with the strongest physical causal closure principles that can plausibly be advocated.

b>: Replacing faulty nineteenth century physics by its orthodox quantum successor converts the earlier materialist conception of nature to a structure that does not enforce the principle of the causal closure of the physical. The quantum laws possess causal gaps, and these gaps are filled in actual scientific practice by inputs from our streams of consciousness. The form of the quantum laws permits and suggests the existence of an underlying reality that is built not on substances, but on psychophysical events, and on objective tendencies for these events to occur. These events constitute intrinsic mind-brain connections. They are fundamental links between brain processes described in physical terms and events in our streams of consciousness. This quantum ontology confers upon our conscious intentions the causal efficacy assigned to them in actual scientific practice, and creates a substance- free interactive dualism. This putative quantum ontology has previously been shown to have impressive explanatory power in both psychology and neuroscience. Here it is used to reconcile the existence of physically efficacious conscious free will with causal anomalies of both the Libet and Einstein-Rosen-Podolsky types.

Epiphenomenalism is the view that mental events are caused by physical events in the brain, but have no effects upon any physical events. Behavior is caused by muscles that contract upon receiving neural impulses, and neural impulses are generated by input from other neurons or from sense organs. On the epiphenomenalist view, mental events play no causal role in this process. Huxley (1874), who held the view, compared mental events to a steam whistle that contributes nothing to the work of a locomotive. James (1879), who rejected the view, characterized epiphenomenalists' mental events as not affecting the brain activity that produces them "any more than a shadow reacts upon the steps of the traveller whom it accompanies".

Some philosophers argue that Descartes was wrong when he characterized animals as purely physical automata – robots devoid of consciousness. It seems to them obvious that animals (tigers, lions, and bears, as well as chimps, dogs, and dolphins, and so forth) are conscious. There are other philosophers who argue that it is not beyond the realm of possibilities that robots and other artificial agents may someday be conscious – and it is certainly practical to take the intentional stance toward them (the robots as well as the philosophers) even now. I'm not sure that there are philosophers who would deny consciousness to animals but affirm the possibility of consciousness in robots. In any case, and in whatever way these various philosophers define consciousness, the majority of them do attribute consciousness to humans. Amongst this group, however, there are philosophers and scientists who want to reaffirm the idea, explicated by Shadworth Holloway Hodgson in 1870, that in regard to action the presence of consciousness does not matter since it plays no causal role. Hodgson's brain generated the following thought: neural events form an autonomous causal chain that is independent of any accompanying conscious mental states. Consciousness is epiphenomenal, incapable of having any effect on the nervous system. James (1890, 130) summarizes the situation.