Dualism went out of style a long time ago, but identity theory also lost favor in the late 1960s early 70s. There are a lot of good arguments against mind-brain identity theory, and specifically "type physicalism" and "reductionism", but the two criticisms that absolutely shattered this way of thinking were Hilary Putnam's multiple realization argument and Donald Davidson's anomalous monism argument. The former essentially postulates that any given mental state is "multiply realizable" by a variety of physical/biological structures thereby creating it impossible to identify a mental state with a physical state (think of how many neurological configurations can cause pain, and not just in humans but in other creatures as well). Davidson's argument basically shows that laws cannot connect mental kinds with physical kinds which is thought to entail the irreducibility of mental kinds to physical kinds. This all gave way to a functionalist perspective on the mind-body problem which is still circulating in various forms today. See
http://en.wikipedia.org/wiki/Functio...phy_of_mind%29 for a good summary of functionalism. If you're interested in learning more about this subject, check out Jaegwon Kim who is considered one of the forefront thinkers in this area. Some of his books such as Supervenience and Mind and even Mind in a Physical World, though great contributions to the Philosophy of Mind, are highly technical. "Philosophy of Mind," also by Jaegwon Kim, is much more digestable. Lastly, it seems the debate on the mind-body problem nowadays focuses almost entirely on mental and physical properties as opposed to mental and physical events. Acknowledging that a mental event can have both mental and physical properties, such as my desire to respond to this post has both the property of being a desire as well as the physical property of being a certain neural configuration in my brain, I tend to side with Jackson and Pettit who argue that there is room for the mental in physical world if the instantiation of a mental property PROGRAMS for the instatiation of a physical property (which can be any number of physical property instantiations, hence the theory is nonreductive) which then kicks off the causal chain of me clicking reply and writing this post.