These two notions being granted, it can be said that statements of "ought" are measured by their "prescriptive" truth, just as statements of "is" are measured by their "descriptive" truth; and the descriptive truth of an "is" judgment is defined by its correspondence to reality (actual or in the mind), while the prescriptive truth of an "ought" judgment is defined according to a more limited scope—its correspondence to right desire (conceivable in the mind and able to be found in the rational appetite, but not in the more "actual" reality of things independent of the mind or rational appetite).