"This is the secret of C's portability: it is the best representation of an abstract computer that we have. Of course, the abstraction is done over the set of real computers, not some imaginary computational devices." -- Alexander Stepanov

One can certainly quibble over the historical accuracy of this, but I think Stepanov describes a worthwhile principle. My sesnse is that a lot of clinical psychology is still trying to abstract over imaginary brains (often by boiling away all the nuance and ambiguity from some ancient philosopher's musings) instead of the set of real brains.