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Philosophy of the Syncretic Academy

Introduction by Charles Siegel

Volume 3 of the Rediscovered Philosophers series

new material in this edition copyright © 2016

Antiochus is important historically and is also a philosopher we can learn from today. He began his career as a skeptic of the New Academy but rejected skepticism in favor of a synthesis of the thinking of the early Academy, the Peripatetics, and the Stoics, which he claimed was a return to the principles of the Old Academy. His synthesis of the ideas of three major schools of classical philosophy can serve as a useful corrective to our modern views, particularly in ethics.

The Mystery of Sosus

Cicero tells us something about Antiochus' rejection of Academic skepticism in the beginning of Book II of Academica. Book II is sometimes called Lucullus, the name of its main speaker, a general and politician whom Antiochus accompanied during his stay in Alexandria in 87/6 BC. Lucullus begins his discourse by saying:

"When I was at Alexandria, as proquaestor, Antiochus was with me, and before my arrival, Heraclitus, of Tyre, a friend of Antiochus, had already settled in Alexandria, a man who had been for many years a pupil of Clitomachus and of Philo [both of the New Academy], and who had a great and deserved reputation in that school…; and I used often to hear Antiochus arguing with him; but they both conducted their discussions with great gentleness. And just at that time those two books of Philo which were yesterday mentioned by Catulus had been brought to Alexandria, and had for the first time come under the notice of Antiochus; and he, though naturally a man of the mildest disposition, (nor indeed was it possible for anyone to be more peaceable than he was,) was nevertheless a little provoked. I was surprised, for I had never seen him so before … Then Antiochus … publish[ed] a book against his own master [Philo], which is called Sosus."

At this time, Philo was in Rome, having left Athens to escape the Mithridatic War, which the Romans fought after King Mithridates VI of Pontus challenged their control of the Greek world. No one knows the names of the books he wrote there, so they are called Philo's Roman books. Many scholars have speculated about why these books angered Antiochus, and later in this introduction, we will advance a theory about what the Roman books said.

Antiochus had already broken with at least some of Philo's earlier ideas before this time. Lucullus' statement says that he argued with Philo's follower Heraclitus of Tyre in Alexandria before they saw the Roman books, but he published a book that criticized Philo openly only after being angered by the Roman books.

Cicero's reply to Lucullus in the dialog shows that the break happened earlier:

Why did he not cross over to some other school, and especially to the Stoics? for this disagreement with the Academy was peculiarly theirs. What? did he repent of Mnesarchus or Dardanus, who at that time were the chiefs of the Stoics at Athens? He never deserted Philo till after the time when he himself began to have pupils.

The two Stoics Mnesarchus and Dardanus were prominent in the 90s BC, dating Antiochus' disagreement with Academic skepticism to this time. Since Cicero says he should have joined the Stoics, Antiochus presumably disagreed with the skeptics by accepting the Stoics' claims that cataleptic perceptions allowed us to have knowledge. This claim is described in Philosophy of the Stoics, and the skeptics' attacks on it is described in Philosophy of the Skeptical Academy.

Heraclitus and Antiochus apparently gave lectures in Rome attacking and defending this theory of knowledge. In the discourse included in this book under the title "Against Skepticism"), Lucullus says he is repeating one of Antiochus' arguments against Heraclitus, and it is actually a lengthy lecture. Though some scholars assume these were public lectures, they might also have been private lectures. Cicero has Lucullus describe them by saying:

…as I was much interested in hearing Heraclitus arguing against Antiochus, and Antiochus against the Academicians, I paid great attention to Antiochus, in order to learn the whole matter from him. Accordingly, for many days, collecting together Heraclitus and several learned men, and among them Aristus, the brother of Antiochus, and also Ariston and Dion, men whom he considered only second to his brother in genius, we devoted a great deal of time to that single discussion.

This certainly sounds like a private lecture, by invitation only.

When he was younger, Antiochus was a prominent student and advocate of Philo's pre-Roman Academic skepticism, which held that we cannot have knowledge, but he became a fierce critic of skepticism when he was older. In the second half of Academica Book II, where Cicero responds to Lucullus' exposition of Antiochus' ideas and defends Academic Skepticism, he says:
But first I must say a few words to Antiochus; who under Philo learnt this very doctrine which I am now defending, for such a length of time, that it is certain that no one was ever longer studying it; and who wrote on these subjects with the greatest acuteness, and who yet attacked it in his old age with no less energy than he had defended it in his youth.

Here, we have a historical mystery. What did Philo write in his Roman books that made Antiochus so angry that he finally wrote a book attacking his teacher Philo, after disagreeing with him for many years? What criticisms of Philo did Antiochus write in Sosus?

A Revisionist History of Philosophy

After rejecting the Skeptical Academy, Antiochus created a revisionist history of philosophy to support his views. He said there was a skeptical "New Academy," beginning with Arcesilaus and continuing through Carneades, Clitomachus and Philo, which abandoned the original ideas of Plato and those who followed him as early scholarchs of the Academy. He claimed that Aristotle and his followers, the Peripatetics, established another school that also expounded the original ideas of the Academy, and that the Stoics' ideas were the same as the Academy's in substance but were expressed using different terminology. Antiochus rejected the New Academy by claiming that he was returning to the original ideas of the Old Academy, that is, of Plato and his followers, of Aristotle and his followers, and of the Stoics.

Antiochus' synthesis of these three schools distorted the history of philosophy. The introduction to Philosophy of the Skeptical Academy shows that the Academy gradually became more skeptical after Plato's death, rather than suddenly shifting from dogmatism to skepticism at the time of Arcesilaus.

And any undergraduate philosophy major knows that there are substantive differences between Plato, Aristotle, and the Stoics. For example, Plato believed that the Forms existed in a world of pure ideas and that our knowledge is based on direct experience of the Forms. Aristotle believed that the Forms exist only as embodied in matter and that our knowledge is based on abstracting the Forms from our sense perceptions. The Stoics believed that our knowledge is based on sense perceptions that are clearly true and that the Forms exist only as concepts in our minds.

Yet we should remember that, when Antiochus talks about the Old Academy, he may be thinking of the immediate followers of Plato, whom we know very little about, rather than of Plato himself. Cicero has Piso say, "Our master Antiochus seems to me to adhere most scrupulously to the doctrine of the ancients, which according to his teaching was common to Aristotle and to Polemo." Polemo (314–269 BC) was fourth scholarch of the Academy, after Plato, Speusippus and Xenocrates, and it is possible that his thought was closer to the Peripatetics than Plato's was.

Antiochus' distortion of history led him to develop some very interesting ideas by synthesizing these three major strains of classical philosophy. Hellenistic philosophy was generally divided into ethics, natural philosophy/theology, and logic/epistemology. We can get a fairly clear idea of Antiochus' beliefs from the surviving writing by and about him. They are summarized in the epitome of Antiochus' philosophy that is the first selection of this book, and this book also includes longer selections by Antiochus about epistemology and ethics.

Because he synthesized all the main strains of Hellenistic philosophy except for the skeptical Academy and the materialistic Epicureans, Antiochus' writing - and particularly his writing about ethics - makes for provocative reading in our skeptical and materialistic age.


The epitome of Antiochus' philosophy in this book has a good brief summary of his ethics, and we are lucky that we also have a complete treatise on ethics by him.

His mainstream classical ethics is based on the idea that every living thing seeks its own survival and development. Plants seek the sunlight that allows them to grow, and animals seek the sorts of food that promote their growth and health. As Antiochus says:

all nature is self-preserving, and has before it the end and aim of maintaining itself in the best possible condition after its kind…. This leads to the inference, that the ultimate Good of man is life in accordance with nature, which we may interpret as meaning life in accordance with human nature developed to its full perfection and supplied with all its needs.

Development is more complex for humans than for other living things, because its perfection includes mental goods, such as knowledge and virtue, in addition to physical goods, such as health and strength.

The virtues - such as the cardinal virtues, Prudence (or Wisdom), Fortitude (or Courage), Temperance, and Justice - are habits that help us and others to live successfully and develop our capabilities fully. But the ability to act virtuously is also an important human capability, so that acting virtuously is not only a means to living successfully but also an important part of living successfully - in Antiochus' view, the most important. Antiochus arranges human goods in a hierarchy: mental goods are more important than physical goods, virtues are the most important of the mental goods, and justice is the most important of the virtues.

Antiochus' ethics is a compromise between Stoic and Peripatetic ethics.

The Stoics believed that only the virtues should be called "good." They said the natural advantages that the virtues aim at are "to be chosen" or are "preferred" but that they are "indifferent" rather than "good." They sometimes called them "preferred indifferents," a self-contradiction. The Stoics wanted our happiness to be completely in our own hands rather than depending on fortune, so they said that a wise man who behaves virtuously is perfectly happy because he has every good thing, even if he lacks natural advantages completely and is starving or being tortured.

The Peripatetics believed that, in addition to virtue, health, some degree of wealth, the opportunity to study, and other worldly advantages were necessary to happiness. Antiochus blames their excessive focus on these worldly advantages on Aristotle's successor, Theophrastus, saying:

…on the chief object of inquiry, namely Happiness, and the one question which philosophy has to consider and to investigate, whether this lies entirely within the control of the Wise Man, or whether it can be impaired or destroyed by adversity, here there does appear sometimes to exist among them [the Peripatetics] some divergence and uncertainty. This effect is chiefly produced by Theophrastus' book On Happiness, in which a very considerable amount of importance is assigned to fortune; though if this be correct, wisdom alone could not guarantee happiness. This theory seems to me to be, if I may so call it, too enervating and unmanly to be adequate to the force and dignity of virtue. Hence we had better keep to Aristotle and his son Nicomachus…

But in reality, Aristotle himself also gave considerable weight to the advantages that fortune brings rather than believing that virtue alone is enough for happiness.

Antiochus compromises between the Stoics and the Peripatetics. He says that there are other goods besides virtue, and he criticizes the Stoics for saying that these goods are "preferred" and "to be chosen" but refusing to admit that they are good. But he also says that virtue is so much more important than other goods that virtue alone is enough for a happy life, though virtue plus other goods are necessary for the happiest possible life. This distinction between a happy life and the happiest life is new in Antiochus.

This sort of classical virtue ethics would be a valuable addition to the current philosophical discussion. Modern ethics generally falls into two schools. Deontological ethics focuses on our duty to obey rules; for example, Kant said that reason provides moral rules that must be obeyed. Consequentialist ethics focuses on the outcome of our actions; for example, utilitarianism says that we should act in a way that produces the most pleasure. Virtue ethics is usually ignored, except by Catholic philosophers, but it has advantages over the two usual modern approaches.

Virtue ethics does not have the cramped feeling of deontological ethics, which assume that we would prefer to act on our inclinations but the moral rules sometimes force us not to. Instead of focusing on rules that restrain our inclinations and make us more moral but less happy, it focuses on virtues that help us and others to live successfully and happily.

Virtue ethics is goal-oriented, like consequentialist ethics. But because its goal is to develop our capabilities, it believes moral activity is valuable in itself rather than just for its consequences.

If modern philosophers say pleasure can be the goal of ethics, then why can't we just as well have development of our capabilities as the goal of ethics? It seems clear that people would live better lives if their goal is to fully develop and use their intelligence, health, strength, musical talent, and other capabilities than if their goal is to seek pleasure and avoid pain. Why has this strain of ethical theory dropped out of the modern discussion, while the hedonism of Aristippus and Epicurus is still with us?
The work by Antiochus that we have named "On Ethics" is the clearest surviving statement of classical virtue ethics - clearer than anything in Aristotle or in Thomas Aquinas. It is the one work of Hellenistic philosophy that should be required reading in undergraduate philosophy classes, because it would open students' eyes to possibilities that modern philosophy generally ignores.

Natural Philosophy

We know little about Antiochus' natural philosophy. The main and almost the only source is the epitome of his philosophy that is in this book.

His natural philosophy begins with ideas that seem to derive from Plato's and Aristotle's idea that nature is made of forms embodied in matter. Underlying the elements of earth, air, fire, and water, there is matter without any qualities, and some active power holds it together, which we can speculate is similar to the Forms of Aristotle and Plato. He says:

…matter itself could have no cohesion, unless it were held together by some power; and that power could have none without some matter to work upon; …. But that which exists from a combination of the two they called at once body, and a sort of quality, as it were.

If this active power is equivalent to the Forms, then Antiochus is closer to Aristotle, who believed in immanent Forms that existed only as embodied in matter, than to Plato, who believed in transcendent Forms that existed independently in the world of pure ideas. As always, when Antiochus speaks of what the old Academy believed, he may be thinking of successors of Plato whom we know little about, rather than of Plato himself.

On top of this physics of form and matter, he adds the Stoic idea of providence, as we can see in this statement from the epitome:

And they say that the parts of the world are all the things which exist in it, and which are maintained by sentient nature; in which perfect reason is placed, which is also everlasting: for that there is nothing more powerful which can be the cause of its dissolution. And this power they call the soul of the world, and also its intellect and perfect wisdom. And they call it God, a providence watching over everything subject to its dominion….

We do not have enough information to say much more than this about Antiochus' natural philosophy. In the section of this book which we have entitled "On Law and Justice," we use a selection from Cicero's De Legibus as evidence of Antiochus belief in the Stoic idea of providence. In addition, some scholars have used what he says about nature and human nature in his ethical writing as hints to his beliefs about natural philosophy.


Logic, as a division of Hellenistic philosophy included etymology, rhetoric and epistemology, and we can see all of these summarized in the epitome of Antiochus' philosophy. "Logic" comes from the Greek logos, which means "word," so this division of philosophy covered the different uses of words.
In the brief section about epistemology in the epitome, Antiochus sounds more like Aristotle than like the Stoics:

They [both Plato's and Aristotle's followers, all of whom Antiochus considered part of the Old Academy that he had revived] said that, although it originated in the senses, still the power of judging of the truth was not in the senses. They insisted upon it that intellect was the judge of things. They thought that the only thing deserving of belief, because it alone discerned that which was always simple and uniform, and which perceived its real character. This they call idea, having already received this name from Plato; and we properly entitle it species.

But they thought that all the senses were dull and slow, and that they did not by any means perceive those things which appeared subjected to the senses; which were either so small as to be unable to come under the notice of sense, or so moveable and rapid that none of them was ever one consistent thing, nor even the same thing, because everything was in a continual state of transition and disappearance. And therefore they called all this division of things one resting wholly on opinion. But they thought that science had no existence anywhere except in the notions and reasonings of the mind; on which account they approved of the definitions of things, and employed them on everything which was brought under discussion.

This is not really what Plato believed, but Aristotle did believe knowledge originated in the senses and that the mind abstracts forms or species from the senses so it can reason about them and determine their truth.

We can see how Antiochus synthesized Stoicism with this Aristotelian view in Lucullus' repetition of a lecture by Antiochus, which this book gives the title "Against Skepticism." This lecture is primarily an attack on the Academic skeptics' criticism of sense perception, but it includes this brief outline of Antiochus' positive epistemology:

… the conclusion of an argument, which in Greek is called apodeisis, is thus defined: - Reason, which leads one from facts which are perceived, to that which was not perceived. For the mind itself, which is the source of the senses, and which itself is sense, has a natural power, which it directs towards those things by which it is moved. Therefore it seizes on other things which are seen in such a manner as to use them at once; others it stores up; and from these memory arises: but all other things it arranges by similitudes, from which notions of things are engendered; which the Greeks call, at one time ennoiai, and at another prolêpseis. And when to this there is added reason and the conclusion of the argument, and a multitude of countless circumstances, then the perception of all those things is manifest, and the same reason, being made perfect by these steps, arrives at wisdom.

Here, again, he takes the Aristotelian view that we abstract notions (forms or abstract ideas) from our sense experience and reason about these notions.

Other parts of this lecture make it very clear that Antiochus believes that Academics' skepticism about the Stoics' claim that cataleptic perceptions are evidently true undermines the basis of this epistemology. If we cannot distinguish sense perceptions that are hallucinations from perceptions of objects in the world, as the skeptics claimed, then we can no longer rely on sense experience as the first step in the Aristotelian progression from sense experience to abstract ideas to reasoning, so we cannot have knowledge.

The lecture that Lucullus repeats is almost entirely a criticism of the Academic skeptics and a defense of the Stoic belief in cataleptic perceptions, but it also shows that this defense of sense perception was the basis of an Aristotelian epistemology.

Because Lucullus says Antiochus gave this lecture in Alexandria, we know that he had already come up with this synthesis at the time he read Philo's Roman books.

Sosus Solved

Now, we have enough background about Antiochus' epistemology to understand the few clues we have about why Philo's Roman books made Antiochus angry.

Sextus Empiricus wrote that Philo's Roman books said:

As far as the Stoic criterion, namely the comprehensible (katalêptikê) perception, is concerned, things are incomprehensible (akatalêpta), but as far as the nature of the things themselves is concerned, they are comprehensible (katalêpta).

A common interpretation of Sextus Empiricus' statement is that Philo invented some new criterion that allows us to comprehend the nature of things even though we cannot comprehend things according to the Stoic criterion, but this interpretation is controversial. For example, David Sedley suggests that it means that the problem is with human comprehension rather than with the nature of things: the nature of things themselves could be understood, for example by the gods, but our human perception makes it impossible for us to understand the nature of things.

We can confirm the common interpretation by comparing Sextus Empiricus' statement with this statement in Lucullus' discourse:

But Philo, while he raises some new questions, because he was scarcely able to withstand the things which were said against the obstinacy of the Academicians, speaks falsely, without disguise, … and also, as Antiochus told him, falls into the very trap of which he was afraid. For as he asserted that there was nothing which could be comprehended, (for that is what we conceive to be meant by akatalêptos,) if that was, as Zeno defined it, such a perception, … extracted and produced out of that from which it originated, such as could be produced from that from which it did not originate. And we say that this matter was most excellently defined by Zeno; for how can anything be comprehended, so that you may feel absolutely sure that it has been perceived and known, which is of such a character that it is even possible that it may be false? Now when Philo upsets and denies this, he takes away also all distinction between what is known and unknown; from which it follows that nothing can be comprehended; and so, without intending it, he is brought back to the point he least intended. Wherefore, all this discourse against the Academy is undertaken by us in order that we may retain that definition which Philo wished to overturn; and unless we succeed in that, we grant that nothing can be perceived.

It seems from this statement that Philo could not stand up against the skeptics' criticisms of cataleptic perceptions, so he continued to say that nothing could be comprehended using the Stoic criterion of cataleptic perception, as the Academic skeptics said, but also came up with some other criterion that let him move beyond skepticism to knowledge. Antiochus became angry because he believed knowledge can only be based on cataleptic perceptions, and he thought that Philo's rejection of this criterion removed any distinction between known and unknown and brought us back to skepticism, though Philo intended to move us beyond skepticism.

Antiochus believed in the Stoic criterion of cataleptic perception all his life, both in his early years as an Academic skeptic, when he believed we could not have any knowledge according to this criterion, and after he developed his own philosophy, when he believed that we could have knowledge according to this criterion. It is not surprising that Antiochus became angry when he saw Philo trying to get around the epistemology that he dedicated his life to.

Antiochus attacked the Roman books in Sosus, which he named after his compatriot, the Stoic philosopher Sosus of Ascalon. Because dialogues are generally named after their main speaker, this book was probably a dialog in which Sosus attacked Philo's ideas from a Stoic viewpoint, defending cataleptic perceptions as the only possible foundation of knowledge.

In addition, Cicero tells us that Philo claimed that there was no difference in the opinions of the Academy throughout its history, denying the distinction between the Old and New Academy that was central to Antiochus' thinking:

Cicero: "Philo, the master of Antiochus, a great man, as you yourself consider him, used to deny in his books that there were two Academies (and we ourselves have heard him assert the same things in his lectures); and he convicts those who say that there are, of palpable mistake."
Varro: "It is as you say, said he, but I do not imagine that you are ignorant of what Antiochus has written in reply to the arguments of Philo."

"Certainly," said I, "I am not…."

Because Antiochus did not write books criticizing Philo before the Roman books, Sosus is presumably the reply of Antiochus that they are talking about, revealing that Antiochus became angry partly because Philo's Roman books denied his history of the Academy.

Finally, Philo's Roman books apparently used weak arguments for his new position. Early in his discourse, Lucullus says that he will only repeat the lecture of Antiochus that dealt with the Academic skeptics:

… we must pass over that part of it [Antiochus' series of lectures debating Heraclitus in Rome] which was bestowed on refuting the doctrines of Philo; for he is a less formidable adversary… Let us speak of Arcesilaus and Carneades.

The arguments of Philo's Roman books also seem to have had no influence on subsequent philosophy, another indication that they were weak. It is possible that Antiochus was angered by the incompetence of Philo's arguments as well as by his new doctrine.
Philo wrote a response to Sosus. A text survives that is probably part of this response, which confirms the impression that Philo was not a formidable philosopher. This text is included in Philosophy of the Skeptical Academy.

Thus, it seems that Antiochus became angry enough to attack Philo openly in Sosus, though he had disagreed with him without attacking him earlier, because Philo's Roman books invented some criterion different from cataleptic perceptions, denied the distinction between the Old and New Academy and - perhaps the last straw - used weak arguments to make the points that were so offensive to Antiochus.

This internet preview does not include footnotes.