Doctrine that some item under investigation is a mere by-product of some process and has no causal influence of its own.
In particular, the claim that the mind is not a separate entity from the body, that conscious phenomena are mere by-products of cerebral or neural processes and have no causal effects on those processes.
One objection to this is the difficulty it has in explaining rational trains of thought: if a thought occurs only because a suitable stage has been reached in a purely mechanical process in the brain, why should the thought be logically related to one before it?
K Campbell, Body and Mind (1970); offers 'new' epiphenomenalism;
Compare also: J Bricke's discussion in Mind (1975)