"Empirical" is derived from ancient Greek, basically meaning, "experience", (from which the word "experiment" is also derived).

"Science" is derived from Latin meaning, "knowledge".

I think the problem arises when psychologists think they can mimic the methodology of the "hard" sciences without considering the possibility that just because that methodology works successfully for things like physics, chemistry, etc. doesn't necessarily mean that's the best methodology for other subjects, (e.g., psychological knowledge).

That is, just because a saw is good for cutting wood doesn't mean it'll be good for pounding in a nail.

Making a metaphysics out of method, and all that...

I think an empirical science (in the modern sense of that term) of "pure" behavior is reasonable, (in the sense of "behavior" being a function of change in the organism - environment relationship that is mediated physiologically).

I'm quite a bit more skeptical of such methodology for the study of "mind", (whatever that is!), which I think requires something different in terms of methodology, (e.g. a phenomenological approach...perhaps?).

I've come to wonder if we could differentiate between an "extraverted empiricism" and an "introverted empiricism" --- "extraverted" and "introverted" referring to the direction in which we oriented our attention --- with modern science utilizing "extraverted empiricism", while psychology, (at least the study of the "mind"), might ultimately require some sort of "introverted empiricism".

Just some thoughts off the top of my head.  

Have a good one,
Jason Bessey