epiphenomenalism

Epiphenomenalism is a philosophical theory on the mind–body problem in philosophy of mind. It holds that subjective mental events are completely dependent for their existence on corresponding physical and biochemical events within the human body, but do not themselves influence physical events. According to epiphenomenalism, the appearance that subjective mental states (such as thoughts and intentions) are causally effective themselves and directly influence physical events is an illusion generated by brain regions such as the prefrontal cortex, with consciousness itself being a by-product of physical states of the world. For instance, the emotion of fear seems to make the heart beat faster, but according to epiphenomenalism the biochemical secretions of the brain and nervous system (such as the stress hormone adrenaline)—not the subjective experience of fear itself—is what causes the rapid rise in heartbeat. Because mental events are a kind of overflow that cannot cause anything physical, yet have non-physical properties, epiphenomenalism has traditionally been viewed as a form of property dualism. In contemporary thought, there are a number of epiphenomenalistic questions that arise within a broadly materialist monism.

== Development == During the 17th century, René Descartes argued that animals are subject to mechanical laws of nature. He defended the idea of automatic behavior, or the performance of actions without conscious thought. Descartes questioned how the immaterial mind and the material body can interact causally. His interactionist model (1649) held that the body relates to the mind through the pineal gland. La Mettrie, Leibniz, and Spinoza all in their own way began this way of thinking. The idea that even if the animal were conscious nothing would be added to the production of behavior, even in animals of the human type, was first voiced by La Mettrie (1745), and then by Cabanis (1802), and was further explicated by Hodgson (1870) and Thomas Henry Huxley (1874).