Schematically, we might propose it as follows:
1. An object, act, inaction, or state of affairs (X) has moral value (V) if and only if normal human beings are disposed, under the appropriate conditions (C), to respond to it (R) with feelings of moral approval or censure
I add the "normal" qualifer to indicate “non-idealized.” This distinction is made to contrast the view being described here from an “ideal observer” theory.
So does "1" entail circularity?