Aristotle, like Plato, drew a strong line of demarcation between matters in which you can have, and those in which you cannot have, certainty; in other words, between the region of opinion and the region of science. Syllogistic reasoning is applicable both to certainties and probabilities, and as such it had been formally drawn out in the ‘First Analytics.’ Its application by means of Dialectic to matters of opinion had been set forth (in anticipation of the natural order of treatment) in the ‘Topics;’ and now Aristotle proceeded in his ‘Second Series of Analytics’ to write the logic of science, and to exhibit the syllogism as the organ of demonstration.
The attitude of Science is of course different from that of Dialectic. In Dialectic two disputants are required, one of whom is to maintain a thesis, while the other by questioning is to endeavour to draw from him some admission which shall be repugnant to that thesis. In Science, on the other hand, we are not to suppose two disputants, but a teacher and a learner. Thus the ‘Second Analytics’ begin with the words—“All teaching and all intellectual learning arises out of previously existing knowledge.” This points at once to a characteristic of Aristotle’s view of Science. In modem times we associate Science most commonly with the idea of the inductive accumulation of knowledge; and thus we talk of “scientific inquiry;” but Aristotle thinks of Science as deductive and expository, and identifies it with “teaching.” If we look at the specimens of scientific reasoning which he gives us in this book, we shall find that a large proportion of
