Modality De Dicto and De Re

Publisher Summary This chapter proposes to consider the origin and the value of a technical distinction that was much used by mediaeval logicians in their discussion of the subject that contains some importance for logic as well as for the history of logic. In “De Interpretatione,” Aristotle tries to determine the rules of opposition between statements of various kinds and, in particular, to say what counts as the contradictory of what. When logicians undertake to set up a theory of necessity and possibility that could be fully explicit and well articulated, they sometimes unfortunately fail to realize that fragments of discourse appear simple because they are familiar may not be really basic for the purpose they have in mind. It is true that Aristotle had no single word like modern “proposition” to cover premises, conclusions, theorems, suggestions, hypotheses, theories, beliefs, tenets, and dogmas. Unfortunately in Aristotle's theory of modal syllogisms, the comparatively simple doctrine is complicated by a development that has worried many succeeding logicians.