By "definitional question," I mean questions like what is knowledge, what is justice, what is love, etc - questions that relate to the definition of certain abstract concepts.
Take the question, what is knowledge, for example. I'm having trouble articulating what is it exactly that philosophers are arguing about when this question comes up?
For example, some philosophers advocate for the classical JTB theory of knowledge, while others argue against it. And I understand this. But what confuses me is what aspect of reality are philosophers measuring these theories against to determine their truth? What thing out in the world that we call knowledge are philosophers analyzing and saying, "yeah the theory ABC seems to better get at the nature of this thing than theory XYZ"?
My initial thoughts regarding my questions were that philosophers were interested in what concept people seemed to be getting at when they talk about knowledge, or justice, or love, etc.
My concerns with this line of thinking were (1) this seems to frame much more of a psychological question than a philosophical one, and (2) this still doesn't seem to get at what philosophers are actually interested in. They aren't just interested in what people seem to think, but what they ought to think, which leads me back to my question of what this ought implies? What thing are philosophers pointing to and saying, "you ought to believe my theory because it better corresponds to the nature of this thing."
I think my question can be most succinctly put this way. Sure theories like JTB, or retributive justice might be coherent and consistent. But what ultimately makes them true? The fact that they might correspond to certain intuitions? The fact that they seem to capture what many people mean when they talk about these concepts?
And I have the same confusion regarding other similar kinds of questions I listed. Could someone shed some light on where I'm going wrong here?