So far we have used "phantasy" only of real or imaginary impressions of sense. But the term was not thus restricted by the Stoics, who divided phantasies into sensible and not sensible. The latter came through the understanding and were of bodiless things which could only be grasped by reason. The ideas of Plato they declared existed only in our minds. Horse, man, and animal had no substantial existence but were phantasms of the soul. The Stoics were thus what we should call Conceptualists. Comprehension too was used in a wider sense than that in which we have so far employed it. There was comprehension by the senses as of white and black, of rough and smooth, but there was also comprehension by the reason of demonstrative conclusions such as that the gods exist and that they exercise providence. Here we are reminded of Locke's declaration: "'Tis as certain there's a God as that the opposite angles made by the intersection of two straight lines are equal." The Stoics indeed had great affinities with that thinker or rather he with them. The Stoic account of the manner in which the mind arrives at its ideas might almost be taken from the first book of Locke's _Essay_. As many as nine ways are enumerated of which the first corresponds to simple ideas-- (1) by presentation, as objects of sense (2) by likeness, as the idea of Socrates from his picture (3) by analogy, that is, by increase or decrease, as ideas of giants and pigmies from men, or as the notion of the centre of the earth, which is reached by the consideration of smaller spheres. (4) by transposition, as the idea of men with eyes in their breasts. (5) by composition, as the idea of a Centaur. (6) by opposition, as the idea of death from that of life. (7) by a kind of transition, as the meaning of words and the idea of place. (8)by nature, as the notion of the just and the good (9)by privation, as handless The Stoics resembled Locke again in endeavoring to give such a definition of knowledge as should cover at once the reports of the senses and the relation between ideas. Knowledge was defined by them as a sure comprehension or a habit in the acceptance of phantasies which was not liable to be changed by reason. On a first hearing these definitions might seem limited to sense knowledge but if we bethink ourselves of the wider meanings of comprehension and of phantasy, we see that the definitions apply as they were meant to apply to the mind's grasp upon the force of a demonstration no less than upon the existence of a physical object. Zeno, with that touch of oriental symbolism which characterized him, used to illustrate to his disciples the steps to knowledge by means of gestures. Displaying his right hand with the fingers outstretched he would say, "That is a phantasy," then contracting the fingers a little, "That is assent," then having closed the fist, "That is comprehension," then clasping the fist closely with the left hand, he would add, "That is knowledge."