I think you have a real point here. Standard dictionary definitions don't simply "report" usage. Both philosophical and standard dictionary definitions "explain" (as you put it) or "interpret" (as I might put it) the meanings of words. And both the authors of standard dictionaries and philosophers may be reasonably described as advancing "arguments" for their interpretations. There are, of course, different methods of argument at play in the production of philosophical and standard dictionary definitions; and philosophers and the authors of standard dictionaries interpret words in different ways, in the light of different audiences and different histories. In short, the contexts of usage with which philosophical definitions and standard dictionary definitions are concerned is generally different (though sometimes overlapping). The word, "valid," for example, is used differently and means something different in the contexts of ordinary conversation and the formal language of deductive logic. ...

Well, there's "important" and there's "important," but I'd say that the most important difference is in the sorts of logical things one can do with each kind of thought. There are many different forms of argument that depend upon what logicians call fully "distributing" their terms. So, from "All people are animals" we can reason quite easily to Anna Nicole was an animal. But from the fact that "That cat is a pet that belonged to Anna Nicole" we can't reason to the idea that "All cats were pets that belonged to Anna Nicole." In fact, you might say that to a large extent, the sciences are concerned with general ideas, rather than concrete ideas, as you describe them. There are, of course, poetic differences, too, that might sometimes be important. Perhaps the most important thing about concrete ideas is that they refer to the existential particularities of one's own life in a way that general ideas don't. Or perhap better, general thoughts are important to one individually only to the extent that...

Yes, issues of speech, morality (and politics) can be rather agitating. Perhaps one way of getting at the issue here is to ask what you mean by "should" when you say "should just do so" and what your friend means by "shouldn't" (and "held against") when he asks with regard to speaking improperly, "shouldn't it not be held against me"? The reason I ask is that philosophers distinguish between what might be called (1) "instrumental" uses of the word "should" and (2) "moral" uses of the word. So, for example, one might say, "To support the load presented by the trucks and cars that drive over it, you should use materials of such and such strength when building the bridge." Or, similarly, "In order to secure your investments, you shouldn't invest in that firm." Or, "In order to cure that disease, you should prescribe this medicine." All these are instrumental uses of the word "should." They're instrumental because they talk about the means that ought to be employed to achieve a certain end. ...