Descriptive versus normative propositions

Propositions are standardly said to be “descriptive” if they talk about the way the universe is, and “normative” if they talk about the way the universe should be. To say that an apple pie should be divided equally between Alice and Bob, or that it would be just to divide the apple pie equally, is not to argue that the pie is in fact currently divided equally. Likewise, to observe that Alice currently gets 60% of the pie and Bob is getting 40% of the pie, is not to argue that the apple pie should be divided unequally. Statements about how an apple pie ought to be divided, or that it’s good or just for a pie to be divided a certain way, or that it is better to divide a pie one way or another, are all “normative” statements. How much apple pie there is, how much it weighs, how the pie was made, where the pieces are currently going, how the pieces of apple pie are being digested, and so on, are all “descriptive” statements.