If definitions are clear and everyone agrees on them, then discussion can be about whether those definitions apply. Discussion is then about the real world. T

If definitions are clear and everyone agrees on them, then discussion can be about whether those definitions apply. Discussion is then about the real world. The definition of murder is pretty clear and widely agreed on; there is plenty of room for discussion about whether it was Smith or Jones who committed it. If definitions are unclear or people disagree on them, then discussion may either be about the definitions and not about the real world, or be incoherent.