  Boole worked mainly with Aristotelian propositions in MAL, using the traditional division into categoricals and hypotheticals.  In LT this division was replaced by the similar but more general primary versus secondary classification, where the subject and predicate were allowed to become complex names, and the number of propositions in an argument became unrestricted. With this the parallels between the logic of primary propositions and that of secondary propositions became clear, with one notable difference, namely it seems that the secondary propositions that Boole considered always translated into universal primary propositions.