He is said to have written eleven books on the No-one fallacy. But what seems to have exercised most of his ingenuity was the famous Liar, the invention of which is ascribed to Eubulides. This fallacy in its simplest form is as follows. If you say truly that you are telling a lie, are you lying or telling the truth? Chrysippus set this down as inexplicable. Nevertheless he was far from declining to discuss it. For we find in the list of his works a treatise in five books on the Inexplicables an Introduction to the Liar and Liars for Introduction, six books on the Liar itself, a work directed against those who thought that such propositions were both false and true, another against those who professed to solve the Liar by a process of division, three books on the solution of the Liar, and finally a polemic against those who asserted that the Liar had its premises false. It was well for poor Philetas of Cos that he ended his days before Chrysippus was born, though as it was he grew thin and died of the Liar, and his epitaph served as a solemn reminder to poets not to meddle with logic-- Philetas of Cos am I 'Twas the Liar who made me die And the bad nights caused thereby. Perhaps we owe him an apology for the translation. ETHIC We have already had to touch upon the psychology of the Stoics in connection with the first principles of logic. It is no less necessary to do so now in dealing with the foundation of ethic. The Stoics we are told reckoned that there were eight parts of the soul. These were the five senses, the organ of sound, the intellect and the reproductive principle. The passions, it will be observed, are conspicuous by their absence. For the Stoic theory was that the passions were simply the intellect in a diseased state owing to the perversions of falsehood. This is why the Stoics would not parley with passion, conceiving that if once it were let into the citadel of the soul it would supplant the rightful ruler. Passion and reason were not two things which could be kept separate in which case it might be hoped that reason would control passion, but were two states of the same thing--a worse and a better. The unperturbed intellect was the legitimate monarch in the kingdom of man. Hence the Stoics commonly spoke of it as the leading principle. This was the part of the soul which received phantasies and it was also that in which impulses were generated with which we have now more particularly to do. Impulse or appetition was the principle in the soul which impelled to action. In an unperverted state it was directed only to things in accordance with nature. The negative form of this principle or the avoidance of things as being contrary to nature, we shall call repulsion. Notwithstanding the sublime heights to which Stoic morality rose. It was professedly based on self-love, wherein the Stoics were at one with the other schools of thought in the ancient world.