 Of all the profound minds born of Zeno's thought, the one who most influenced the Stoic philosophy was, without question, Chrysippus, for if Chrysippus had not existed, neither would the Stoic. His thought is so ubiquitous in Stoic doctrine that many place him alongside Zeno as honorary co-founder of the academy. He was born in 280 BCE on the southern coast of what is now Turkey in a city known as Soli. While still a youth, he journeyed to Athens and began training to become a long-distance runner. This proved to be short-lived as he would soon discover philosophy and begin his ascent to the peak of that Hellenistic age. The then head of the Stoic academy, Clanthys, would adopt him as his pupil and school him in the metaphysics, ethics, logic, ontology, and epistemology of the Stoic philosophy. A few years would pass and Chrysippus would choose to venture away from the porch and teach Stoicism elsewhere, though he would eventually return in around 230 BCE following the death of his master would become the third man to lead the Stoic. He was such a prolific writer that perhaps even the mighty Voltaire would stand reverent at the sheer scale of his works. Which other philosophic figure could match his 705 book library or his daily 500 line quota? An unusual death seemed to be a fashion among the Stoic leaders and in the year 207 BCE, Chrysippus would certainly perpetuate it. If Diogety's laertious is to be taken at his word, Chrysippus apparently laughed himself to the Aleutian Fields. How might you ask? Well, after witnessing a donkey eating some figs at the 143rd Olympiad, he would add to the situation a comical comment, after which he burst into a fit of laughter ultimately culminating in his death, this or he simply just drank too much undiluted wine. His philosophy defended a materialistic ontology and offered its readers an alternative to the Aristotelian and Platonic metaphysics that had up until that point dominated antiquity. His cosmos was a deterministic one and he maintained that human felicity was achieved through living in accordance with nature and in striving to synchronize one's life with virtue. He was perhaps best known by his extensive work in the field of logic and for this reason I would like to begin here in exploring his contributions to the Stoic philosophy. The propositional logic developed by Chrysippus is, without a question, most responsible for the logic associated with the Stoics. What would place him apart from not only his predecessors Xeno and Clanthys, but also from the immensely influential system of logic developed by Aristotle? Well, Aristotelian logic concerns itself with the interrelations of terms such as when we examine the terms car and wheel in the Syllagism, if all cars have wheels, and I drive a car, then my car has wheels. Stoic logic, on the other hand, was concerned rather with the interrelations of propositions. Take the proposition it is day and apply the logic of Chrysippus in this manner. If it is day, it is light. But it is day, so it is light. Along with his work on propositional logic, he was also said to have completed 12 works on the Lyre paradox, 7 on amphibole, and another 9 on various other logical quandaries. Clement of Alexandria would even name him Master of Logicians, and Diogenes later she has said if gods used dialectic, they would use none other than that of Chrysippus. Unfortunately, with the new Platonist preference to Aristotle, his form of logic would fall out of style until the modern propositional calculus proved what the Stoics already knew, that Chrysippus had achieved something momentous. Let us move on to his ethics. If you are familiar with Stoicism, then without question you are familiar with the ethics of Chrysippus, one where the goal of life is to live in complete accordance with nature. The difficulty arises when one is confronted with the task of how to achieve this vague ideal. It seems to Chrysippus that the man who lives in accordance with reason lives in accordance with virtue, and virtue is to live in accordance with one's experience of the things which come about by nature. So in short, to achieve this Stoic ideal, we must place virtue above all else. Any disruptive emotion should be cast aside as they are contrary to nature and considered an enemy to right judgment. Freedom is in fact obtainable, but only after one has liberated themselves from irrational desires, and to achieve this your emotions must be subjected to uncompromising reason. So let us then establish a sound epistemological foundation. For Chrysippus, the soul is like that of a blank sheet of paper, prepared at any time to have any number of impressions written upon it. This differs from Xeno and Clanthes in that they believe the soul only capable of receiving one impression at a time. Upon receiving an impression, we are at once aware of not only its existence, but also the cause of its existence. This makes up what we perceive to be reality. Some impressions lack a corresponding impressor or an underlying real object, and in order to distinguish between those impressions that are true and those that are false, Chrysippus believed that we use a combination of memory, classification, and comparison. With this theory of knowledge, Chrysippus places heavy emphasis on the proper function of one's cognitive abilities and begins the transition from the theoretical into the empirical. Without question, Chrysippus stands among not only the most influential Stoics, but also among the most influential philosophers of the Hellenistic Age. And while we covered much of his philosophy here in this video, there's even more that I wasn't able to get to. With 705 books, it seems that with Chrysippus I bit off more than I could chew. Though I hope you were able to glean the essence of his teachings from what I did cover. If you want to learn more about Eastern and Western philosophy, consider subscribing to the channel. And as always, thank you for talking philosophy with me. Until next time.