One great appeal of this new orthodoxy is the misunderstanding that is a modern development recently uncovered by science. In fact it dates back to presocratic philosophers like Pythagoras and Empedocles. It was Hippocrates however (460BC) who fully expressed our 'modern' position :
Men ought to know that from the brain, and from the brain only, arises our pleasure, joys, laughter, and jests, as well as our sorrows, pains, griefs and tears. Through it, in particular, we think see, hear and distinguish the ugly from the beautiful, the bad from the good, the pleasant from the unpleasant - On the Sacred DiseaseThe more recent and familiar form was introduced in 1956 by U.T Place and J.J.C Smart in their "Is Consciousness a Brain Process?". The authors proposed a scientific hypothesis that mental events are physical events in the brain. That is, Ψ(mental event like pain or taste) = Φ (corresponding physical event in the nervous system) in much the same way as Water = H2O. Place and Smart believed future developments in science would prove their hypothesis. Their position became known as the identity theory.
The challenge became explaining how "taste and "brain state" could refer to the same thing in purely materialistic terms. Consider water again. When we say water is h2o, we mean water consists of nothing but h2o molecules. The colour of water, it's taste, it's feeling, it's very appearance etc are all stripped from this account as secondary qualities depending upon a subjective mind.
If we accept the identity theory, it should be possible to explain the properties of Φ and have a complete account including taste, feeling, pain etc. That such things exist are brute facts. When we drink water, it has a certain taste. The problem is how to account for this taste. At the risk of belabouring the point, water is nothing but h2o molecules. The taste of water therefore is an interaction between h2o molecules and a human. But even if we list the properties of Φ, the effect that drinking water has on us, we cannot explain how the water tasted. This is what the identify theory requires: the subjective must be reunited with the objective within a materialistic framework.
The most popular attempt to resolve this difficulty is the 'double aspect' theory: experiences such as taste and the neural activity seen in the visual cortex in association with that experience are two aspects of the same item. But this is pure desperation as observers are still required to generate this double aspect.
Other attempts explain consciousness in causal terms. Water has taste because h2o molecules cause taste when they interact with the human nervous system. This approach is more sensible but still flawed.
Philosopher John Searle puts the analogy this way:
Water is to H2O molecules as conscious experience is to neural activity.Searle argues that large molecules of h2o are identical to the appearances we associate with water because such appearances are just large aggregations of h20 molecules. Similarly consciousness is identical to large aggregations of nerve impulses; nerve impulses cause consciousness.
The obvious problem is Searle claims nerve impulses are both identical to consciousness and that nerve impulses cause consciousness. This is logically impossible. We cannot claim A causes B and claim A is identical to B. To avoid this objection we are forced into accepting consciousness as an illusion produced by large aggregations of nerve impulses firing within our brain.
The post title asks "Are you your brain?". The orthodox answer is not 'yes' because the identity theory remains problematic, but rather 'your sense of self hood is an illusion caused by large aggregations of active nerve impluses'. I'll explore this position in another post.