According to Cicero’s account (Academ. Quæst. IV. 47), Zeno illustrated the moments of this appropriation by a movement of the hand. When he showed the open palm he said that this was a sensuous perception; when he bent the fingers somewhat, this was a mental assent through which the conception is declared to be mine; when he pressed them quite together and formed a fist, this was comprehension (κατάληψις), just as in German we speak of comprehension [Begreifen] when by means of our senses we lay hold of anything in a similar way; when he then brought the left hand into play and pressed together that fist firmly and forcibly, he said that this was science, in which no one but the wise man participated. This double pressure, my pressing with the other hand that which is grasped, is said to signify conviction, my being conscious of the identity of thought with the content. “But who this wise man is or has been the Stoics never say,” adds Cicero; and of this we shall afterwards have to speak in greater detail. In fact, the matter is not made clear through this gesticulation of Zeno’s. The first action, the open hand, is sensuous apprehension, immediate seeing, hearing, &c.; the first motion of the hand is then, speaking generally, spontaneity in grasping. This first assent is likewise given by fools; it is weak, and may be false. The next moment is the closing of the hand, comprehension, taking something in; this makes the ordinary conception truth, because the ordinary conception becomes identical with thought. By this my identity with this determination is indeed set forth, but this is not yet scientific knowledge, for science is a firm, secure, unchangeable comprehension through reason or thought, which is that which rules or directs the soul. Midway between scientific knowledge and folly is the true Notion as the criterion, although as yet it is not itself science; in it thought gives its approbation to existence and recognizes itself, for approbation is the harmony of a thing with itself. But in scientific knowledge a perception of the first elements and determinate knowledge through thought of the object is contained. Thus the ordinary conception as apprehended is thought; scientific knowledge is the consciousness of thought, the knowledge of that harmony.