THREE:On the other hand, a theory of reasoning based on the relations of concepts, instead of on the relations of judgments, necessarily leaves out of account the whole doctrine of hypothetical and disjunctive propositions, together with that of the syllogisms based on them; since the elements of which they are composed are themselves propositions. And this inevitable omission is the more remarkable because alterna381tive and, to a less extent, hypothetical arguments form the staple of Aristotles own dialectic; while categorical reasoning never occurs in it at all. His constant method is to enumerate all possible views of a subject, and examine them one after the other, rejecting those which are untenable, and resting content with the remainder. In other words, he reaches his positive conclusions through a series of negative premises representing a process of gradual elimination. The First Analytics is itself an admirable instance of his favourite method. Every possible combination of terms is discussed, and the valid moods are sifted out from a much greater number of illegitimate syllogisms. The dialectic of Socrates and Plato followed the same procedure. It was essentially experimentala method of trial, elimination, and selection. On going back still further, we find that when there is any reasoning at all in Homer, it is conducted after the same fashion. Hector, in his soliloquy before the Scaean Gate, imagines three alternative courses, together exhausting the possibilities of the situation. He may either retreat within the walls, or offer terms of peace to Achilles, or fight. The first two alternatives being rejected, nothing remains but the third. This is the most elaborate example; but on many other occasions Homers actors are represented as hesitating between two courses, and finally deciding on one of them.The study of psychology with Plato stands in a fourfold relation to his general theory of the world. The dialectic method, without which Nature would remain unintelligible, is a function of the soul, and constitutes its most essential activity; then soul, as distinguished from body, represents the higher, supersensual element of existence; thirdly, the objective dualism of reality and appearance is reproduced in the subjective dualism of reason and sense; and lastly, soul, as the original spring of movement, mediates between the eternal entities which are unmoved and the material phenomena which are subject to a continual flux. It is very characteristic of Plato that he first strains an antithesis to the utmost and then endeavours to reconcile its extremes by the interposition of one or more intermediate links. So, while assigning this office to soul as a part of the universe, he224 classifies the psychic functions themselves according to a similar principle. On the intellectual side he places true opinion, or what we should now call empirical knowledge, midway between demonstration and sense-perception. Such at least seems to be the result reached in the Theaettus and the Meno. In the Republic a further analysis leads to a somewhat different arrangement. Opinion is placed between knowledge and ignorance; while the possible objects to which it corresponds form a transition from being to not-being. Subsequently mathematical reasoning is distinguished from the higher science which takes cognisance of first principles, and thus serves to connect it with simple opinion; while this again, dealing as it does with material objects, is related to the knowledge of their shadows as the most perfect science is related to mathematics.138
A human being is a part of a whole, called by the magic and know universe.