Interactionism

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

Interactionism is the philosophical claim that matter and consciousness are two distinct substances that causally influence each other. In other words, the human mind operates in a way that is not fully determined by the laws of physics, and the same might be true for other conscious systems. QRI rejects this view.

Prior to the advances of modern neuroscience, interactionism used to be an influential position among philosophers and likely the dominant position among the general population due to its compatibility with the religious conception of a non-material soul. Nowadays, it is a minority view among philosophers, though it may still be a popular view among lay people.

As of today, no phenomena known in the neuroscience literature require mind-specific laws to be explained. This fact is often cited as evidence against interactionism, which predicts the existence of such laws. On the other hand, our understanding of the brain remains incomplete, and the bulk of the remaining mystery pertains to the implementation of higher cognitive functions. The slow rate of progress in understanding such functions can be considered evidence for interactionism, though it is equally well explained by the Electromagnetic Hypothesis, which is consistent with Dual-Aspect Monism.

A different argument pertains to the usefulness of interactionism in resolving the Mind-Body Problem. If the causal effects of consciousness are lawful and merely fall outside the current set of physical laws, one can define an extended set of laws that includes those specific to consciousness. With this construction, Interactionism reduces to a version of dual-aspect monism plus a rejection of Physicalism.