I've never understood why the mind-body dichotomy is considered coherent.
The mind body dichotomy, quickly stated, is the idea that there is a nonphyiscal phenomena, called the mind, whose attributes and behavior are distinct from the body. A practical consequence on, say, a doctor is that he must determine whether a cause is physical or mental.
I suppose it all comes down to definitions - i never saw the mind as much more than software running on the brain, with the body as a host of attached peripherals. I'd built up this model long before I'd read anything about the MBD, and immediately thought, "why is it a dichotomy? The mind is the behavior of the brain. if it's mental, it's also physical. I can understand how that's a little unhelpful, but it's no big mystery."
What I find even a bit immature is this: the body, while distinct from the brain, is intimately integrated with the models the mind generates to interact with the world. that means that, fundametally, the mind _is_ the body - at least, in part.
so i suppose I'm taking issue with the word 'dichotomy'. the practical problem still stands - does a doctor treat the physical aspect, orr the mental?
since the two are intimately tied, I think the answer must be "both". a physical issue may have mental repercussions, and a mental issue can cause real physical problems.
for the former, think of amputees with phantom limbs. for the latter, consider someone who has phantom back pain, causing rsi's on his major joints from comensating for his pain.
in both cases, it's incumbent on a doctor to clear away the symptoms as best as he can before focusing on the real causes - it's best to have as much of the bullshit out of the way when getting down to business.
still, the concept of the mind is a tricky one, but i believe i can describe a theroetical emergence in a plausible manner:
the mind started out as a simple decision maker. this was the fish brain. all it could do is figure out: eat, kill, both, or run.
as we grew more complex, so did the mind. new featues included goal searching ("i'm hungry; let me look for one of those things that made me less hungry before"), prediction ("that thing over there looks as though it could eat me; i'd better stay clear"), agent detection, ("that odd shadowy thing over there could be a predator"), and feedback ("hey, here's a scenero that i've formed with my predictive models; what do you think?")
i believe that between feedback, predictivity, and agent detection, we form the basis for what we internally experience as 'mind'.
but i'm probably just imagining it ^_^