 Abelard also referred to this distinction as the distinction between personal and impersonal readings of a modal sentence, the de re sense corresponding to the personal reading and the de dicto sense to the impersonal reading because when the expression ‘necesse est’ or ‘possibile est’ is used at the beginning of a sentence, it lacks a personal subject. Abelard states that this distinction is related to Aristotle’s distinction between per divisionem and per compositionem in the Sophistici Elenchi (4, 166a23–31). What is new is Abelard’s contention that modal discussions should proceed by distinguishing the different possible readings of modal sentences, moving on to consider their quantity, quality, and conversion as well as their equipollence and any other relations holding between them on these different readings. Abelard’s program thus became the standard operating procedure in medieval treatises on logic.