Just like inference from felt perception to an external world is illogical, right? Or the inference from the apparent logicality of certain statements to an external, objective reality to which that appearance refers, is also totally illogical, yes?
First of all I'd like to clarify a possible point of confusion: I deny that ethical and logical properties are directly sensed, leaving open the possibility that they refer to or reflect some aspects of reality.
Ordinary perceptions explain why you'd believe in moral perception even if there were no such thing; moral perception is superfluous in ethics and impotent elsewhere. So if we accept Occam's Razor as an axiom, then moral realism is illogical while ordinary perceptual realism is not.
Close examination of the notion of moral oughts quickly dispels this, I feel. When one says that one ought not to do something, one means something very different from having some attitude towards that thing. You have to sacrifice part of the meaning of the notion to jam it into a naturalistic explanation.
Close examination of the notion of heat quickly dispels physics, I feel. When one says that fire is hot, one means something very different from describing vibrational motion of particles. You have to sacrifice part of the meaning of the notion to jam it into a physical explanation.
Lemme hammer out the skeleton of this analogy. Attitudes explain morality just as vibrations explain heat. A theory of moral facts is as empty and obsolete as caloric theory in physics: these extraneous concepts get Razored away because the entire explanatory burden is already carried by familiar, scientifically demonstrable concepts (attitudes, and vibrations). However, one may routinely and correctly moralize or use the notion of heat without understanding the true nature of underlying phenomena.
Your argument is
ad populum, because you infer the truth of X from the fact that 'one' speaks as though X is true. Any number of people can believe X and speak as though X is true, when in fact they are all mistaken.
You have to at least assume belief in the genral reliability of your logical faculties in order to justify anything at all. The structure is built on logic, it does not justify logic. If there are such basically trustworthy faculties, why not admit conscience, which seems similar?
Occam's Razor. Ordinary sight/smell/etc. plus memory collectively explain the surface phenomena of logic and ethics. What evidence supports the hypothesis of direct perception?
The whole idea of "reliability of your logical faculties" presupposes the existence of logical perceptions which track real properties of the world. Logic is just a system for analyzing beliefs/statements; and using a system doesn't commit us to any perceptual explanation of that system. We happen to have wound up in a mental state containing that system, perhaps because it is a purely intellectual construct which suits our needs. Any acceptable explanation, of why we use logic, must be based on logic, but that's fine. Within the system we'd like to know how the system came about and what kind of system it is (in this case, perceptual or projected). Doubts about the reliability of logic do nothing for you, since they hurt the hypothesis of direct logical perception far more than they hurt logical projectionism.
