In science, a theory is a coherent set of beliefs about how some phenomenon works that constrains your expectation about what you will observe to some subset of what you might observe. In the humanities and in most of social science, and apparently in nursing, it is the other way round: a theory is a coherent set of beliefs about how some phenomenon works that constrains your actual observations to lie within what the theory says they will be. This is why there are so many theories of the same thing, and no-one seems to care whether any of them are true, or even think that is a sensible question to ask.

This is the best formulation of this class of criticisms of the social sciences that I have ever read.