Epiphenomenalism[I] is a brand of dualism in which mind and matter are two different manifestations of existence, but holding mind to be ontologically inferior to matter, and there is some form of logical flow – not necessarily causality per se – from matter to mind.
The term as used in the late 19th century provides another analogy through its definition: a secondary symptom of a disease, one that parallels the disease but does not contribute to it. The fallacy of assuming that if x follows y then x is caused by y, is called “post hoc ergo propter hoc” (i.e. “after this, therefore because of this”).
An implication of mind’s secondary title is that even our (mental) volitions to action do not cause action, but are rather manifestations of (what can be called by analogy) the physical (e.g. neurological) volition.
One of the first descriptions of epiphenomenalism comes from the Swiss, Charles Bonnet, saying that “the soul is a mere spectator of the movements of its body” (1775). Later (the British) Shadworth Hodgson, “States of consciousness are not produced by previous states of consciousness, but both are produced by the action of the brain” (1865). (Nb. The ‘flow’ of consciousness is deceitful, and each datum of consciousness can be delineated by virtue of the matter that caused it). Thomas Huxley refers to the case of a French soldier who falls into apparent trances in which he can commit complex behaviours but is unresponsive to stimuli like pain (i.e. observations suggest non-consciousness; c. 1874). (Huxley’s point is that consciousness is independent of behaviour; Huxley believed in an epiphenomenal theory).
Brian McLaughlan specifies two strands of epiphenomenalism. One is event- or token-epiphenomenalism (whose faithful includes Huxley); physical events are causes but mental events cannot be causes. The other is called property- or type-epiphenomenalism; an event is a cause by virtue of its physical, but never its mental, properties. [I’m struggling to see the virtue of this differentiation. Property-epiphenomenalism seems to be predicated upon property- (cf. substance-) dualism in the first place, and that this is the reason for the difference.
Arguing for epiphenomenalism: one argues from the philosophical corner, because one is forced to allow this position since one’s other beliefs introduce the requirements by which one ends up here. In the 18-19th centuries, it was built upon the fields of two other discordant theories: dualism and scientific naturalism (or mechanism). Dualism is the result of observations that conclude that mind and matter are too different to be considered in a unified manner. So too, scientific pursuits abandoned vitalism, and so there was nothing but inert, mechanical materialism. Despite science’s independence of non-materialism, dualism insists upon it, and thus as a sort of compromise results in epiphenomenalism.
Another train of arguments results at this conclusion after beginning from the debate about mental causation.
[I] This journal entry is based on the “Epiphenomenalism” entry in the Internet Encyclopedia of Philosophy (IEP).
