ABSTRACT
Medieval people with an interest in learning would have known that dialectic was the art of effective argumentation. An argumentation was successful if it moved someone from doubt to conviction about the truth or falsity of some proposition. Greater familiarity with dialectic would have shown its differences both from science and from rhetoric. The job of the scientist was to demonstrate necessary truths about the natures of things. The task of the orator was to persuade an audience to pursue or to avoid a particular course of action. The function of the dialectician was to investigate critically any significant opinion that was controversial and that fell beyond the scope of science or rhetoric. Thus, dialectic was useful in everyday reasoning about human affairs whether personal, political or religious. It was essential to the conduct of commercial, legal and medical proceedings. As a critical discipline dialectic guided discovery of the premises of science as well as those of oratory. Finally, dialectic influenced education by offering principles and methods for instruction, exercise and examination.
