Epiphenomenalism

Interactionism, Epiphenomenalism, and Dual-Aspect Monism can be classified by the causal roles they ascribe to matter and consciousness. Directed arrows indicated causal influence, and the $\approx$ symbol indicates an underlying substrate with two aspects.

Epiphenomenalism is the claim that consciousness arises from material states or processes but does not itself have causal effect. The term is based on the concept of a causal epiphenomenon, which is an event that is caused by other events but is itself a causal dead-end. Epiphenomenalism almost always describes a realist view of consciousness. QRI rejects Epiphenomenalism.

Critiques

The most common criticism of epiphenomenalism is that it is self-defeating because the causal inefficacy of consciousness makes it impossible to study. Specifically, epiphenomenalism denies any connection between our professed beliefs about consciousness, which are determined entirely by physical causes, and consciousness itself. Thus, Epiphenomenalism logically implies that one of the following (or a combination of both) is true:

1. We are mistaken about what consciousness is like (e.g., a state we think is blissful is actually unpleasant).
2. We are correct about what consciousness is like, but due to luck rather than necessity.

In The Conscious Mind, philosopher David Chalmers argues that humans can have genuine knowledge about the nature of consciousness that is compatible with its causal inefficacy because knowledge is not solely based on material states. Even if one accepts this argument, however, it applies only to beliefs about consciousness (as opposed to verbal reports) and only to conscious states that are experienced in the moment, since beliefs about past states depend on either memory or reports from other people, both of which are physical phenomena.

Another common critique of Epiphenomenalism is based on Occam's razor, since the causal disconnect between consciousness and matter necessitates the existence of additional laws governing consciousness. Thus, a universe in which epiphenomenalism is true is not maximally simple.