As noted before, on the surface we are doing psychology, not philosophy, because we seem to be concerned with cause not reasons or justification. This is wrong because we are concerned ultimately with the consequences, the meaning, the significance of what we now know to be the cognitive psychology of human agents. We are concerned with the implications of this psychology, not of the specific content. If you ignore human psychology, human capacities and limitations then you are doing something other than human philosophy. There may be a more generic philosophy of agents, but we can’t do it yet.
Human philosophy is exhausted by the possibilities of human cognitive psychology. If there is no ghost in the machine then we are left with only the mechanics of the machine and that is the end of it. Once you reject the ghost you must acknowledge the limits. This has not yet been done, it is what we are trying to do. We cannot escape with the normative escalation because this is still subject to the theory of limits. The desirable must include or is limited by the possible. Similarly the theory of philosophy as meaning, as referents of universal terms, of conceptual analysis, all must be based on what are cognitive capabilities really are.
The dogmas of meaning are probably especially important to consider here. The idea that meaning is essential to language, that meaning is what is important, what is to be analyzed or discovered ignore the fact that meaning is a theoretical term that has no known experimental referent in cognitive psychology. Meaning is what we say its all about, what it is really, however, is process. Meaning has become the cover term, the mask, the mystery for and about our cognitive functions, the modern philosophical equivalent of coloricfluid or the physicist’s ether.
What is the case, what ought to be the case. The universe of possible discourse outside the area of purely formal systems like logic or mathematics is pretty well exhausted by these two possibilities.