Until well into the nineteenth century it was almost possible to regard logic as a subject that had sprung fully formed from the head of Aristotle. By this was meant, of course, deductive logic, and it would be too much to expect him to have given birth to nondeductive logic as well. If anything, one would expect the founder of deductive logic to have spent his time emphasizing the distinction between deductive arguments and all “mere persuasions.” The case is almost the exact opposite.
