Skepticism in Philosophy

A Comprehensive, Historical Introduction

Henrik Lagerlund

• Publisher: Routledge
• Year: 2020
• Print ISBN: 9781138555549
• eBook ISBN: 9781351369954
• Topic: History
• Subtopic: African History
• Index: History

In this book, Henrik Lagerlund offers students, researchers, and advanced general readers the first complete history of what is perhaps the most famous of all philosophical problems: skepticism. As the first of its kind, the book traces the influence of philosophical skepticism from its roots in the Hellenistic schools of Pyrrhonism and the Middle Academy up to its impact inside and outside of philosophy today.

Along the way, the book covers skepticism during the Latin, Arabic, and Greek Middle Ages and during the Renaissance before moving on to cover Descartes' methodological skepticism and Pierre Bayle's super-skepticism in the seventeenth century. In the eighteenth century, it deals with Humean skepticism and the anti-skepticism of Reid, Shepherd, and Kant, taking care to also include reflections on the connections between idealism and skepticism (including skepticism in German idealism after Kant). The book covers similar themes in a chapter on G.E. Moore and Ludwig Wittgenstein, and then ends its historical overview with a chapter on skepticism in contemporary philosophy. In the final chapter, Lagerlund captures some of skepticism's impact outside of philosophy, highlighting its relation to issues like the replication crisis in science and knowledge resistance.

1

Pyrrhonism and Sextus Empiricus

The only group of philosophers during Ancient times that called themselves skeptics were the Pyrrhonists. They derived the origin of their philosophy from Pyrrho of Ellis (365/360–275/270 bce), but it was given its main form much later by Aenesidemus in the first century ce. He supposedly wrote down this philosophy in a work of eight books called Pyrrhonian Discourses. Unfortunately, as is the case with a lot of Greek philosophy, it is lost. The main source of Pyrrhonian skepticism is instead Sextus Empiricus (second century ce). Sextus had very little influence on the general philosophy of his time, but he has had an enormous influence on later philosophy, particularly from the sixteenth century onwards. So much so, that it could be argued that besides Plato and Aristotle, Sextus should be seen as the third most influential Greek philosopher of all time.

Pyrrho apparently wrote nothing. His student, Timon of Philius (325/320–235/230 bce), is the source of almost everything we know about him. It has been speculated that he is the actual author of the philosophical views later attributed to Pyrrho. Whatever the truth may be, even though Pyrrho inspired the skeptical philosophy of Ancient times, it seems clear that he was not really a skeptic himself – at least if we compare his view with Sextus’. In the first chapter of his most famous work, Outlines of Pyrrhonism (often shortened to PH after its Greek title), Sextus draws up three kinds of philosophies. He says that there are those who think that they have found the truth, whom he calls the dogmatic philosophers. Most Ancient philosophy falls under this heading. He places Plato, Aristotle, the Stoics, and the Epicureans in this group. The second group includes those that think that the truth cannot be apprehended, and in this group he places the Academic philosophers, who are also sometimes called negative dogmatists (we will return to them in Chapter 2). The skeptics belong to the third group, and they are still searching for the truth – ‘seeker’ or ‘someone searching’ is the proper English translation of the Greek word ‘skeptikos’.

As Timon is reported to have described the philosophy of Pyrrho, it includes three parts, namely, firstly an account of how things are in themselves; secondly, a statement of what attitude we should have towards those things; and, thirdly, an outline of what will result as a consequence of that attitude. In the first part, he states that the world is equally undecided and unmeasurable; therefore, our senses do not tell the truth or are unable to, which entails the second part that we must not trust our senses and must be without opinion and belief as to how the world really is. At the third stage this implies that we must not assent to anything, which he thinks, then, will lead to tranquility (in Greek, atarâxiâ). Aspects of these three parts can be found in later Pyrrhonism, like the part of not holding beliefs, not assenting, and tranquility as the goal of skepticism, but according to Sextus’ classification, Pyrrho, it seems to many scholars, must be classified as a dogmatic philosopher, since he claimed that the world is in a certain way, albeit in an undetermined way.

There is also another way in which Pyrrho is not a good model for skepticism as it came to be spelled out by Sextus, namely, in how he lived his life. This is particularly problematic, since the later Pyrrhonists often portrayed him as a role-model; although in doing so they were very selective about what reports about his life they chose to emphasize. Pyrrho seemed to have distrusted the senses so much that he constantly put himself in harm’s way and had to be saved by his students. He, for example, is said to have walked out in front of horses in the streets, but he also, at least on one occasion, fled from an aggressive dog. Given the dangers to his own person of his philosophical views, Pyrrho is reported to have lived a quiet life away from other people. Later Pyrrhonists, however, emphasized stories about his indifference and tranquility. As, for example, a story reported by Diogenes Laertius (180–240 ce), the Ancient historian of Greek philosophy, about Pyrrho in a storm onboard a ship. He unlike others was very calm and is said to have pointed to a pig, calmly eating despite the storm, with the words, “in such tranquility should the wise man keep himself” (DL 9.68).

There are a lot of similarities between Pyrrho’s behavior and the people Aristotle describes in his Metaphysics (IV) who deny the law of non-contradiction. Aristotle ridicules these people, because he thinks they are fooling themselves, since it is impossible to live your life without abiding by the principle. He wonders, why “does a man walk to Megara and not stay at home thinking he ought to walk? Why does he not walk early some morning into a well or over a precipice, if one happens to be in his way? Why do we observe him guarding against this, evidently not thinking that falling in is alike good and not good?” (1008b12–16). Pyrrho seems to some extent to have tried to live like these people – ignoring the practical implications of living in a world governed by the principle. Sextus does not think this is the way to live life as a skeptic, as we shall see, but it points to an often-repeated objection to Ancient skepticism, namely, that it is impossible to live by their philosophy.

Aristotle’s treatments, in the same part of the Metaphysics, of Democritus and Anaxagoras also betray similarities with Pyrrho’s position and his early Greek predecessors. Aristotle thinks they have been misled by focusing on how the world appears and consequently they see the world as containing contradictions and contraries that are true at the same time. According to him, they are relativists and subjectivists. Perhaps this is also the best way of describing Pyrrho’s own thinking. He is not so much saying that the world is undecidable and unmeasurable, but that it appears to be, which would put him more in line with later Pyrrhonists. However, the correct interpretation of Pyrrho’s three statements is controversial and debated by scholars.

The philosophy of Pyrrho lived on for a few generations after him, but eventually died out. It was not until the first century ce that Pyrrhonism was reborn at the hands of Aenesidemus. Again, we know very little about him, except that he seems to have broken off from the Academy, which had turned skeptical under the leadership of Arcesilaus (more about him in Chapter 2). Aenesidemus is said to have accused the Academy of having become too much influenced by Stoic philosophy, which is also why he characterized them as dogmatic philosophers. Sextus seems to have thought Aenesidemus had dogmatic tendencies himself, however. He says in one of his works (M 8.8) that Aenesidemus asserts that there are differences among appearances and what appears to be common to everyone is true. He also, although this is debatable, seems to indicate that there are similarities between Aenesidemus’ view, and Pyrrho’s for that matter, and Heraclitus’ (PH 1.210). Particularly the view that contraries hold of the same thing, indicating the easy slide from skepticism to relativism and subjectivism, as suggested by the passage from Aristotle already mentioned, and which will resurface several times in this book.

The only Pyrrhonist we have enough textual material preserved from is Sextus. It is only in relation to his work that we can come to know what Pyrrhonism was. Scholars have not been very nice to Sextus, however. The famous historian of modern skepticism, Richard R. Popkin, calls him “an obscure and unoriginal Hellenistic writer” in the first edition of his book The History of Scepticism, and he has traditionally been seen as a source of not only Pyrrhonism, but Hellenistic philosophy in general, and not as an independent thinker in his own right. It was not until the 1968 book Scepticism by the Scandinavian philosopher Arne Naess that Sextus started to be taken seriously as a philosopher. Instead, we should see Sextus’ works, particularly the Outlines, as a presentation of Pyrrhonian skepticism, but a very sensitive and intelligent presentation by a talented philosopher.

Almost nothing is known about Sextus Empiricus’ life. We do not even know exactly when he lived. The best estimate is sometime between 100 ce and 300 ce. Diogenes Laertius lists him as the penultimate name in a long list of Pyrrhonian skeptics (DL 9.116). He might have been active in Rome, but we cannot be certain. He was a doctor, however. We know that because he tells us this himself (M 1.260, PH 2.238). Both Galen, another famous doctor, and Diogenes list Sextus among doctors of the empirical school, hence his name ‘Empiricus’. At the end of the first book of Outlines, Sextus argues that even though there are similarities between the empirical school and skepticism they are ultimately different, since the followers of the medical school make assertions about matters that are unclear, which a skeptic would never do.

Outlines of Pyrrhonism (PH), sometimes in English also called Outlines of Skepticism, is by far Sextus’ most important and influential work. It is divided into three books. Book I is a general introduction to Pyrrhonism, whereas the two other books are collections of objections to so-called dogmatic philosophies. Book II deals with objections to logic and Book III deals with physics and ethics. He follows the Stoic division of philosophy into these three parts, which had become traditional in Hellenistic times. Historically, a second work is also attributed to Sextus, although it is not one single work. There are 11 books, which are referred to by one Latin name, Adversus Mathematicos (M), that is, literally, Against the Mathematicians. The eleven books are the following: (1) Against the Grammarians, (2) Against the Rhetoricians, (3) Against the Geometers, (4) Against the Arithmeticians, (5) Against the Astrologers, (6) Against the Musicians, (7) and (8) Against the Logicians, (9) and (10) Against the Physicists, and (11) Against the Ethicists. They are often referred to using their individual names.

In the beginning of Outlines (PH 1.7), Sextus describes some characteristics of the Pyrrhonian skeptic. He notes that a skeptic has an investigative character and is an inquirer. She is also suspensive, which is because a skeptic suspends judgment, or holds back assent, as he expresses it. Furthermore, a skeptic is aporetic, since she puzzles over things and investigates everything. Finally, she is a Pyrrhonian, in the sense that she is a follower of Pyrrho. Many of these characteristics are virtues of a scientist in the seventeenth- and eighteenth-century sense, and also perhaps characteristics of a good philosopher in general. What is the difference between a healthy ‘skepticism’ or inquisitive attitude and a Pyrrhonian skepticism? To a large extent, it seems to be a matter of degree. The Pyrrhonian pushes these characteristics to their extreme and much further than we would consider normal for a scientist or, perhaps, a non-Pyrrhonian philosopher, and, in this sense, skepticism is not just an attitude, but also a philosophy in itself just like other Hellenistic philosophies.

To get a clearer idea about what Sextus thinks Pyrrhonism is, let us have a look at his definition of it. He writes:

Skepticism is an ability to set out oppositions among things which appear and are thought of in any way at all, an ability by which, because of equipollence in the opposed objects and accounts, we come first to suspension of judgment and afterwards to tranquility.

(PH 1.8)

He adds directly after this passage that by ‘ability’, he does not mean anything special, just that we are able to or can simply do it, that is, set out opposites among the appearances of things. Following this quotation, then, we can say that skepticism foremost involves four things: (i) an ability to set out oppositions among appearances, (ii) equipollence, (iii) suspension of judgment, and (iv) tranquility.

The first thing to notice about this is, of course, the similarity of this definition to Pyrrho’s original position as reported by Timon. The second thing is that a skeptic sets out to find oppositions among appearances. What does this mean? The emphasis on appearances is important for Sextus. A skeptic takes appearances or what appears to her as the starting point. In this respect, she starts out in the same way as other philosophers, namely, by trying to infer reality from what appears to her, but in her inquiries the skeptic comes to the realization that there is no consistent way to describe reality. In her investigations, the skeptic pursues a method of setting out so-called equipollences between appearances. These are appearances of equal strength that are opposed to each other, and if such an equipollence can be set out, then there is no basis for accepting one appearance over another. Hence, the prudent thing to do, then, is to suspend judgment. The skeptic does not say that these equipollences always exist, that is, that the world is like this, as it seems Pyrrho claimed, only that at the level of appearances, the skeptic will search for them and try to spell them out.

Another thing to note about Sextus’ definition is about the notion of the suspension of judgment. It is often referred to simply by its Greek name, epochê. It is a standstill in the mind where we cannot see a reason for accepting one position or one appearance over another. The way this works, as we shall develop in more detail later in this chapter and in the next chapter, is that the skeptic is presented with a philosophical or scientific claim of some sort, and then she sets out to find arguments and appearances that support the opposing view. This is part of her investigation, that is, she is looking for counter-arguments. Perhaps a little bit like the scientist does in the twentieth-century philosopher of science Karl Popper’s view. She is looking to falsify scientific theories. If the skeptic finds such an argument, then she is presented with an equipollence that suggests that she must suspend her judgment. Sextus leaves open the possibility that the skeptic may not find a contradictory argument or appearance. This is why skeptics are inquirers, and not dogmatists, since they leave it open that the finding of the truth of things is possible. It goes without saying that Sextus himself presents no such situation and recommends suspension of judgment in all the cases he investigates.

A fourth thing to notice in relation to suspension of judgment is that it implies that a skeptic is supposed to live her life without beliefs. I will return to this below and ask what it means to have a belief, according to a Pyrrhonist, and whether it is possible to live without beliefs. Sextus is explicit (PH 13), however, that a skeptic does not hold beliefs. Obviously, she feels hunger and thirst like everyone else, but she does not commit to things or states of affairs as true. A skeptic as Sextus sees her also follows the law and the custom of the land where she lives without making a judgment about whether these laws are good or bad, true or false.

The final part of the definition above is about tranquility or atarâxiâ, as it is called in Greek. Tranquility is the aim of skepticism, or the goal of skepticism, according to Sextus. To explain how the skeptic came to realize that she could reach tranquility through skepticism, Sextus retells a story about the painter Apelles. He writes:

They say that he was painting a horse and wanted to represent in his picture the lather on the horse’s mouth; but he was so unsuccessful that he gave up, took the sponge on which he had been wiping off the colours from his brush, and flung it at the picture. And when it hit the picture, it produced a representation of the horse’s lather. Now the Sceptics were hoping to acquire tranquility by deciding the anomalies in what appears and is thought of, and being unable to do this they suspended judgment. But when they suspended judgment, tranquility followed as it were fortuitously, as a shadow follows a body.

(PH 1.28–29)

The skeptics came upon what they were searching for by chance and realized that suspension of judgment of appearances that are equipollent seems to cause tranquility. Hence, tranquility in opinion and moderation of feelings, as Sextus puts it, are traits of the skeptic. It is also important to note in relation to this that, for Sextus, Pyrrhonism is a way of life or, differently put, a practical philosophy, the aim of which is to generate a certain state of mind. In this respect Pyrrhonism is not different from other Hellenistic philosophies like Stoicism or Epicureanism, whose stated goals are also tranquility, but which ...

Table of contents

• Cover
• Half Title
• Endorsements
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Preface
• List of Abbreviations and References
• Introduction
• 1. Pyrrhonism and Sextus Empiricus
• 2. Academic Skepticism
• 3. Augustine and Early Medieval Skepticism
• 4. Al-Ghazâlî and Skepticism in Medieval Arabic and Greek Philosophy
• 5. God as a Deceiver: External World Skepticism in Later Medieval Times
• 6. Skepticism in the Sixteenth Century: Montaigne, Charron, and Sanches
• 7. Descartes’ Methodological Skepticism, Bayle’s Super-Skepticism, and Berkeley’s Anti-Skepticism
• 8. Hume’s Skepticism and Hume on Skepticism
• 9. The Anti-Skepticism of Thomas Reid, Lady Mary Shepherd, and Immanuel Kant as well as Skepticism in German Idealism
• 10. G.E. Moore and Ludwig Wittgenstein on Skepticism
• 11. Skepticism in Contemporary Philosophy
• 12. Non-Philosophical Skepticism
• Index