By incidence or direct contact have come our notion^ of sensible things; by resemblance notions whose origin is something before us, as the notion of Socrates which we get from his bust ; while under notions derived from analogy come those which we get (1) by way of enlargement, like that of Tityos or the Cyclops, or (2) by way of diminution, like that of the Pygmy. And thus, too, the centre of the earth was originally conceived on the analogy of smaller spheres. Of notions obtained by transposition creatures with eyes on the chest would be an instance, while the centaur exemplifies those reached by composition, and death those due to contrariety. Furthermore, there are notions which imply a sort of transition to the realm of the imperceptible : such are those of space and of the meaning of terms. The notions of justice and goodness come by nature. Again, privation originates notions ; for instance, that of the man without hands. Such are their tenets concerning presentation, sensation, and thought. The standard of truth they declare to be the apprehending presentation, i.e. that which comes from a real object — according to Chrysippus in the twelfth book of his Physics and to Antipater and Apollodorus. Boethus, on the other hand, admits a plurality of standards, namely intelligence, senseperception, appetency, and knowledge ; while Chrysippus in the first book of his Exposition of Doctrine contradicts himself and declares that sensation and preconception are the only standards, preconception being a general notion which comes by the gift of nature (an innate conception of universals or general concepts). Again, certain others of the older Stoics make Right Reason the