The position in philosophy of mind known as “epiphenomenalism” is fallacious, even nonsensical, and thus should be rejected.
The epiphenomenalists hold “that mental events are caused by physical events in the brain, but have no effects upon any physical events.” Their view is a mix of “property dualism” with “physicalism”. I’ll define “property dualism” as meaning “the position in which mental and physical properties exist, and that mental properties come into being from some physical substances (brains, for example).” And “physicalism” as “the position in which everything that exists is the result of the laws which are valid for the physical world.”
In their view, the aspects of our mind — our thoughts, knowledge, emotions, desires, feelings of pain, and volition, these things which we think influence and guide our physical actions and latter mental states — are only useless by-products of physical processes. The only things that are causally effective are physical processes and interactions. (See the Stanford Encyclopedia of Philosophy entry and Wiktionary entry on Epiphenomenalism.)
This position results in a fundamental change in how we’re supposed to understand causal relationships. As I’m typing this sentence, it’s not because I’m trying to make a point, but exclusively because of neurons firing off and other brain processes. When one studies (studies?) for an exam, the activity is caused only by physical events in the brain: conceptual knowledge and the connections of logic are only illusions, according to the epiphenomenalist view.
Arguments for Epiphenomenalism
So what are the arguments and evidence in favor of this position, one might ask?
Strictly speaking, there are none. (While arguments have been offered which use the position to address problems in the philosophy of mind, such as the “No-Gap Argument,” I’m referring specifically to arguments which report observable facts and makes inferences accordingly. If I’m mistaken, please do point them out.)
From what I’ve gathered, epiphenomenalism is only a development from the “physicalist” position in the philosophy of mind. No positive evidence has ever been offered to establish the position’s validity. As Sven Walter notes in his entry on “Epiphenomenalism“:
Arguments in favor of a philosophical theory typically focus on its advantages compared to other theories–that it can explain more phenomena or that it provides a more economical or a more unifying explanation of the relevant phenomena. There are no arguments for epiphenomenalism in that sense.
Arguments against Epiphenomenalism
Regardless of this lack of argument, the position (1) commits the fallacy of “self-exclusion” and (2) is internally inconsistent.
(1) The epiphenomenalist claims, as knowledge, that brain events produce mental events, and that the latter are causally inefficacious–presumably, this also includes beliefs. In effect, he’s claiming that he’s previously witnessed the evidence and logically established that his viewpoint is true (i.e. that he believes he has knowledge). While at the same time, his position as an epiphenomenalist implies that his beliefs and observations have nothing to do with the fact that he’s now advocating that position, as such advocacy would be the exclusive result of brain events (recall that only physical processes are causally effective, on his view). By his own theory, he’s being made to believe and produce epiphenomenalist “word sounds” by brain activity, which make his claim to knowledge meaningless.
In a paper on an Objectivist perspective on psychology, Dr. Edwin Locke notes that determinists, as a result of their own theory, can’t even claim something along the lines of “I’m being made to emit these word sounds in favor of determinism” as objectively true knowledge, since their position eliminates all claims of knowledge. In the same vein, the epiphenomenalist position reduces all claims to meaninglessness.
In light of this, to continue to hold that the position of epiphenomenalism is genuine knowledge is to commit the “self-exclusion” fallacy. Epiphenomenalism commits the fallacy of “self-exclusion” because the position would invalidate itself (i.e. would be self-contradictory), unless it excludes itself from the scope of the its own claim; such a move is unwarranted, and thus fallacious, because the scope of the claim does include the epiphenomenalist’s doctrine.
Simply put, the epiphenomenalist position amounts to: “all claims are meaningless by-products of the brain–except for this one, which (somehow) is real knowledge.”
(2) Regarding epiphenomenalism’s internal inconsistency, I largely agree with the argument presented by Titus Rivas and Hein von Dongen in their paper “Exit Epiphenomenalism: A Demolition of a Refuge.” Here is my own formulation of the “logical inconsistency argument”:
(i) Epiphenomenalism is a form of dualism, which holds (roughly) that the mental and physical are ontologically distinct from each other (i.e. that physical things have properties different from mental things). The position thus has a concept of “mental,” “consciousness,” “thought,” and so forth.
(ii) Due to epiphenomenalism’s acceptance of dualism, and its own explicit position about mental events, its view is that the concepts of consciousness (or “mental things” or “mental units”; e.g. thoughts, volition) refer to actual parts of reality–specifically the epiphenomena of brain activity which are not reducible to such activity (thus leaving us with a non-reducible–yet causally impotent–mental existence).
(iii) The only way to establish that these concepts of mental units refer to something real is through introspection, i.e. by becoming aware of our own conscious experiences (i.e. mental units). This introspective evidence thus serves as the base for epiphenomenalism’s concepts of consciousness. Such introspection, however, is a causal effect by one’s consciousness on the concept-formation process when one attempts to form such concepts of consciousness.
(iv) Epiphenomenalism is thus logically inconsistent. It presupposes that there is a valid reason for accepting the existence of conscious experience (namely introspection), and yet its explicit position makes the ability to figure out anything about these experiences impossible; this is because introspection, according to the epiphenomenalist claim, would itself be a causally impotent by-product of brain processes, and thus useless.
Epiphenomenalism is incoherent, and thus untenable. Due to the contradictions which result from applying the position to its advocates’ claims to knowledge, or from checking what the position presupposes in comparison to what it advocates explicitly, epiphenomenalism should be judged as “nonsensical” and discarded for some other theory.