Judgment internalism about evaluative judgments is the view that there is a necessary internal connection between evaluative judgments and motivation understood as desires. The debate about judgment internalism has reached a standoff some time ago. In this paper, I outline a new argument for judgment internalism. This argument does not rely on intuitions about cases, but rather it has the form of an inference to the best explanation. I argue that the best philosophical explanations of how we know what we desire require that judgment internalism is true, which gives us a good reason to believe that judgment internalism is true.