Plutarch twits Chrysippus with inconsistency, because in the face of this declaration as to the order of treatment, he nevertheless says that morals rest upon physics. But to this charge it may fairly be replied that the order of exposition need not coincide with the order of existence. Metaphysically speaking, morals may depend upon physics and the right conduct of man be deducible from the structure of the universe but for all that, it may be advisable to study physics later. Physics meant the nature of God and the Universe. Our nature may be deducible from that but it is better known to ourselves to start with, so that it may be well to begin from the end of the stick that we have in our hands. But that Chrysippus did teach the logical dependence of morals on physics is plain from his own words. In his third book on the Gods he says 'for it is not possible to find any other origin of justice or mode of its generation save that from Zeus and the nature of the universe for anything we have to say about good and evil must needs derive its origin therefrom', and again in his Physical Theses, 'for there is no other or more appropriate way of approaching the subject of good and evil on the virtues or happiness than from the nature of all things and the administration of the universe--for it is to these we must attach the treatment of good and evil inasmuch as there is no better origin to which we can refer them and inasmuch as physical speculation is taken in solely with a view to the distinction between good and evil.' The last words are worth noting as showing that even with Chrysippus who has been called the intellectual founder of Stoicism the whole stress of the philosophy of the Porch fell upon its moral teaching. It was a favourite metaphor with the school to compare philosophy to a fertile vineyard or orchard. Ethic was the good fruit, physic the tall plants, and logic the strong wall. The wall existed only to guard the trees, and the trees only to produce the fruit. Or again philosophy was likened to an egg of which ethic was the yolk containing the chick, physic the white which formed its nourishment while logic was the hard outside shell. Posidonius, a later member of the school, objected to the metaphor from the vineyard on the ground that the fruit and the trees and the wall were all separable whereas the parts of philosophy were inseparable. He preferred therefore to liken it to a living organism, logic being the bones and sinews, physic the flesh and blood, but ethic the soul. LOGIC