 Influenced by the new ideas about logical modality, William of Ockham (Summa logicae), John Buridan (Tractatus de consequentiis, Summulae de Dialectica) and some other fourteenth-century authors could formulate the principles of modal logic much more completely and satisfactorily than did their predecessors. Questions of modal logic were discussed separately with respect to modal propositions de dicto and de re; modal propositions de re were further divided into two groups depending on whether the subject terms refer to actual or possible beings. It was thought that logicians should also analyze the relationships between these readings and, furthermore, the consequences having various types of modal sentences as their parts. Ockham, Buridan and their followers largely dropped thirteenth-century essentialist assumptions from modal syllogistic. They regarded the Aristotelian version as a fragmentary theory in which the distinctions between different types of fine structures were not explicated and, consequently, did not try to reconstruct Aristotle’s modal syllogistic as a consistent whole by one unifying analysis of modal propositions; they believed, like some modern commentators, that such reconstruction was not possible. (For fourteenth-century modal logic, see King 1985; Lagerlund 2000; Thom 2003; Knuuttila 2008, 551–567; Read 2021.)