What is Epiphenomenalism?
Property P is epiphenomenal with respect to property Q if exemplifications of the former are causally inefficacious with respect to exemplifications of the latter, yet there is some link between the two. Of interest to, e.g., psychologists and philosophers of mind, is the claim that mental properties are epiphenomenal with respect to physical properties. Our question here is:
Is consciousness epiphenomenal with respect to behaviour?Historically
: The exemplification of some physical properties causes the exemplification of mental properties, but no exemplifications of mental properties cause anything further-most especially, they do not cause exemplifications of physical properties; or, neither causes the other. period.???
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interactionism
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epiphenomenalism
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parallelism (no causal connections)
apologies to Richard Taylor
More recently
: Mental properties are related to physical properties by some means other than causation, and it is not the case that an occurrence of a state/event causes the occurrence of any other state/event in virtue of the first state's mental properties.
Meaning epiphenomenalism
: If Ella breaks a glass by singing a sentence, it is the frequency of her utterance that is responsible, not the meaning of that utterance.
Angledness
Epiphenomenalism?:Imagine two machines that sort wire models of two-dimensional closed geometrical figures, sorting rectangles into their own bin. One machine operates by counting the number of angles on the item (say, it envelops it and counts points of sharp contact), and the other counts the number of sides (perhaps it counts the number of times it must change direction when tracing the circumference). Feed each machine a wire rectangle. The first registers it as rectangle because of the number of its angles, and the second because of the number of its sides. The angledness of the item is epiphenomenal to its winding up in the "rectangle" bin, in the case of the second machine.
Whenever two distinct properties are co-instantiated, the "epiphobic" can worry about epiphenomenalism.
For example, take the following popular view:
Mental properties (including consciousness) supervene on physical properties:
Let A be the set of mental properties, and B the set of physical ones. A supervenes on B just in case: Necessarily, for each x and each property M in A, if x has M, then there is a property P in B such that x has P, and necessarily, if any y has P, it has M.
This formal definition is intended to capture the idea that mental properties depend on and are determined by physical properties.
M
(imagine four "arrows" running from the type M to each of the types P)
P1------P2------P3------P4
Supervenience of types
m
(imagine an "arrow" running from this instance of an M property to this instance of a P-property (in this case, of type P2))
p2
Supervenience of a token