The half dozen most seminal Philosophy books

The half dozen most seminal Philosophy books

Professor Richard Sorabji

I want to draw some of the threads of the last three years together by looking at the books that have been most seminal for my personal study of Philosophy, which is not to say they are the most important in the abstract. This will involve encountering some new ideas and revisiting some old ones, but in their original context. I shall confine my selection to the first 1100 years of Western Philosophy, which was written in Greek or Latin. I shall also mention ancient books and authors without putting them in my small selection. This is true of Plato in Athens of the 4th century BC. It is foolish to say who is greater, Plato, or his pupil, Aristotle. Without Plato, we would not have had Aristotle, but they are great in complementary ways. Plato has the brilliant imagination. Aristotle wants everything sewn up across a vast canvas. Philosophy needs both kinds of genius. All one can say is which better fits one's own temperament. I happen to like the sewers-up. The other best example of these were the Stoics, who set up school, also in Athens, a generation after Aristotle. But the sewers-up are not greater, just complementary.

One of Plato's most seminal works was his account of the creation of the physical world, the Timaeus. But, with the subsequent approval of the Neoplatonists, he wrote less on the physical world than Aristotle, and my first selection for this occasion will be Aristotle's account of the physical world in the Physics.

1. Aristotle's Physics, 4th century BC

Aristotle, like Plato, worked in Athens in the 4th century BC. Archaeologists believe they have found traces of the public space where he taught, before his successor gave the school some private property of its own. Aristotle's Physics is divided into 8 short books, scarcely longer than modern chapters, and Book 2 gives some of Aristotle's most seminal ideas. According to Book 2, chapter 3, there are four sorts of explanation and of explanatory factor. Only one of them is like our notion of cause. It is important that Aristotle sees cause as a type of explanatory factor, because that suggests one of two answers to the problem, still found intractable today, of whether everything that happens, including your actions tomorrow, has been fixed and inevitable all along. The most popular reason for thinking so is that whatever happens has a cause, so your actions tomorrow have earlier causes, and those causes have earlier causes, and the chain of causes goes back to before you were born. So, it is thought, it was already fixed before your birth what you would do tomorrow. One reply, which I have based on Aristotle, but which is not Aristotle's own reply, is that Aristotle is right to connect cause with explanation, rather than with necessitation. An explanation does not have to represent what it explains as inevitable or necessary. It can be a complete explanation without implying inevitability, because what counts as a complete explanation depends on the question to be answered. If a cause is a central factor within a certain kind of complete explanation, it does not follow that it is part of some conditions that make the thing to be explained inevitable. That is how I would avoid the inevitabilist conclusion by building on an Aristotelian insight.

Aristotle himself offers a different answer, not here, but when he returns to the subject in a different work called not Physics, but Metaphysics (Book 6, chapter 3). At least I have taken him there to be attacking the premise that whatever happens has a cause. If a cause is an explanatory factor, this premise is wrong, because, as Aristotle says, not everything has an explanation. To take his example, if for a good reason the thirsty man goes to the well at 2 o'clock and for an unconnected good reason the murderers go to the well at 2 o'clock, it does not follow that there is any reason why the parties went to the well at the same time. It is, as we say, just a coincidence. But these coincidences that have no explanation can nonetheless have important consequences, in this case the man's being murdered. Aristotle's account of coincidence is first drafted in our book, Physics Book 2, chapters 5 to 6. A coincidence is a combination of two items, in this example two visits to the well, where a combination of this sort is not the norm and not self-explanatory. Each component may have a perfectly good explanation, but, on Aristotle's eventual view, the combination does not.

So much for the first of the four types of explanation, but what about the other three? Concerning material and formal explanation, Aristotle's system would go against the tendency of recent philosophy to reduce everything to its material explanation, while ignoring its formal explanation. The material explanation of a thing is often the components of a thing, whether they are physical matter or not. The material explanation of a vase is the clay of which it is made, the formal explanation is the shape or structure. Anger, says Aristotle, is not just a physiological process. That is the material explanation of anger. But there is also a formal explanation, the desire to get even. I recently argued in these lectures that I am not just a series of psycho-physical events in a stream. That leaves out the formal explanation. I am the one who has or does, the one who owns, the psycho-physical events. Ownership would be Aristotle's formal type of explanation. Things should not be reduced to their components; their structures are crucial.

Aristotle's 4th and last type of explanation is purpose, and he sees purpose in biology. This is not conscious purpose. His God is not a Creator, nor does he think that nature consciously designs and creates. Aristotle means what modern biologists mean when they talk of the purpose or function of something. I have suggested, in line with Plato and Aristotle, that to say that the purpose or function of the heart is to pump blood is an evaluative statement, which claims not merely that an effect of the heart is to pump blood, but that this effect confers some good or benefit on the organism. Does the statement of purpose or function also explain the presence of a heart? Yes. How does it explain? In many different alternative ways, I believe. The modern evolutionary biologist who offers pumping blood as an explanation of the heart's presence is appealing to the idea that nature will have non-consciously selected the heart for conferring this benefit. But Aristotle consciously rejects the natural selection account in our Physics Book 2, chapter 8. It had been offered before him by Empedocles. But Aristotle, while rejecting it, could still cite the benefit conferred as explanatory. For example, it shows that the presence of the heart is not an anomaly, but can be brought under the general law (not his word) that distinct parts of the body do normally confer a benefit.

In 8 big pages of Greek, then, a dozen pages in the complete Oxford translation, Book 2 has given us an account of four types of explanation, and the absence of explanation, dealing with cause, coincidence, opposition to mere materialism and the case for purpose in nature. One interesting thing is that Aristotle offers no argument for his four types of explanation. Sometimes a great philosopher says, ' See it like this', and leaves you to judge whether the picture offered isn't more illuminating than anything you would otherwise have had. The proof of the pudding is in the eating, not always in a set of arguments.

I have discussed only one 8-page book out of 8, and that is the set of 8 pages I would most recommend to get an idea of Aristotle at his best. More briefly, what do the other books of the Physics have to say? In Book 4, Aristotle attacks the ideas of 3-dimensional space, and of vacuum, which would be empty 3-dimensional space, and also of time empty of events. About time he states a puzzle that was to have a long history. How can time exist, since some is past and gone, some is yet to come, so that only the present exists. But how long is the present? Strictly only a sizeless instant, so not long enough to be a part of time. If none of the parts of time exist, how can time exist?

Book 3 contains the account of infinity which is so widely taught in schools even today, as an ever expandable finite number, rather than a more than finite number. This enables Aristotle to argue that space is finite. It also fits very well with Aristotle's idea of an unending future. But how does it fit with his idea of a beginningless past? He seems to be arguing that the sequence of years exists only part at a time, unlike individuals, which exist with all their parts at a time. The idea may be that there only ever exists a finite number of years, namely one. But if that is his point, there remain at least two difficulties. One is his worry in Book 4 that only one instant of the present year strictly exists. The other is that past years in his beginningless universe form a more than finite set, with all the problems that involves, even if they are defunct years.

What Aristotle thinks in Books 6 and 8 that his account of infinity does do is to solve Zeno's paradoxes of motion. Zeno is wrong to threaten us that we cannot reach the door because we would have to finish going right through a more than finite number of sub-distances, half way and before that a quarter, and before that an eighth, and so on. There will only be an expandable finite number of sub-distances marked out, whether physically, e.g. by chalk marks, or in thought. But why should Zeno depend on the sub-distances being marked out? Aristotle complains that otherwise the sub-distances will have only potential existence. But surely Zeno can raise a puzzle about a more than finite number even of potential sub-distances. What Aristotle needs is not for the sub-distances to be potential, but for their infinity to be potential in the special sense of being an expandable finitude, rather than a more than finite number. The trouble is that the number of potential sub-distances is more than finite.

Aristotle's understanding of infinite divisibility in Book 6 is particularly impressive, whether he is talking about the discontinuities of motion that would result if space were not infinitely divisible, or about whether we are in motion or at rest at the instant of transition between the two.

There is an overall theme to the Physics. Physics is the study of nature, so nature has to be defined in Book 2, chapter 1. Natural things have an internal cause of change or movement, which is their nature, whereas artefacts have to be moved or changed from the outside. This means that motion and change also have to be defined (Books 1 and 3). And the final book, 8 , having argued that motion has no beginning, looks for an ultimate cause of motion. A thing cannot literally move itself, as Plato thought. Eventually we need an unmoved mover, to avoid an infinite regress. That mover needs to be immaterial, because matter is finite in size, and so cannot house the infinite energy needed for producing unending motion. This is the first version of the argument that finishes elsewhere by claiming that the ultimate mover is an immaterial God.

2. Stoics of 1st century AD, Seneca and Epictetus.

Let me now skip. Some of the most exciting developments in Western Philosophy occurred in the first century BC, and still more the 1st century AD. Among other things, there was a ferment of new ideas about the self, not only fresh ideas about the true self, or one's best self, but also a brand new interest in personal identity over time, due to the Stoic belief in history repeating itself identically with the same people coming back, and the Epicurean belief in the possibility of the chance reassembly of our atoms. This is the period currently least of all studied, and so in 2004 I shall with my colleague, Bob Sharples, be holding a weeklong conference to study it.

In the first century BC, Lucretius and Cicero began to translate Greek Philosophy into Latin, forging a new vocabulary for the purpose, and filling out for us the philosophy of the Greek Epicureans and Stoics. Lucretius' charming Epicurean verses would be high on my list, if I were going beyond half a dozen works. In the first century AD, we find a Greek-writing Platonist Plutarch, whose Moral Works should be in every home. They tell you everything you need to know, how not to be obsequious, or a busybody, the pleasures of marriage, consolation on death in the family, how to control anger, how to learn from your enemies, how to think of your past, which animals are cleverest, how to be concise. What is the most concise letter in history. Alexander the Great's father threatened the Spartans, 'If I invade you, I shall turn you all out'. They replied, 'If'. If I had to choose one volume in the 14-volumes of the Loeb series, I should choose volume 6. Within that, the short treatise On Tranquillity (37 small Loeb pages) recommends weaving a self by telling an autobiographical narrative.

But still more interesting are two Stoics of the first century AD, both very influential on European culture. Epictetus, the former slave, offered in Greek the most uncompromising version of Stoic morality for young pupils who wanted a full training. The main Discourses and the short Handbook are available in 2 Loeb volumes. The Handbook was used also in Christian monasteries, and has long been available in English. I have a translation of 1694. A remarkable woman, Elizabeth Carter, first translated the longer Discourses into English in 1758, and Thomas Jefferson also contemplated translating Epictetus. Epictetus advocated shrinking your concept of the self, so as to become inviolable. His leg had been broken when he was a slave, and he thinks that if your concept of self does not include your body, or even all of your mind, but only your propensity to make morally good decisions, the true you is something which the tyrant cannot control. You must understand what is under your control and what not. This was the system which Admiral Stockdale, whose leg was also broken, used to withstand 19 occasions of torture and 4 years of solitary confinement in Vietnam, and it is already explained by Epictetus in the 4 pages of the first chapter of Book 1 of the Discourses.

Just a little earlier in the century, Seneca, tutor to the tyrant Nero, and eventually his victim by compulsory suicide, provided letters of Stoic advice in Latin to a possibly fictional character, who wanted to progress more comfortably in the direction of Stoicism. He has to learn about the rat race not necessarily being worthwhile, and how not to worry about his health. The teaching gradually becomes more extensive as the series of letters progresses. As well as the letters in the Loeb volumes are short moral essays, from which I should select On Anger. Seneca is never in favour of anger. An alternative reaction to outrages performed by tyrants is suicide, an option which he sees as guaranteeing your freedom from tyranny. Seneca provides the fullest Stoic account of the stages in anger, and of how to exert control. First, it appears to you that you have been put in a bad position and it would be good to get even. These evaluative appearances can already cause physical symptoms, but so far none of this matters and none can be prevented. The physical symptoms are not yet anger. But it gives you a chance to step back and consider whether your position really is a bad one and whether getting even really is good. At that stage, you are free to reassess the situation, and if you fail to do so, the anger becomes your fault. The anger is your voluntary acceptance, thinkingly or unthinkingly, of the evaluative appearances of good and bad. The greatest of the ancient doctors, Galen, was later to complain, that though this was good advice as far as it went, you must first get your physiology right, which he offered to do through your diet, and we shall see that the Neoplatonist Porphyry agreed. I think it is true that either may be needed, a reassessment of attitude, or a correction of physiology. But the reassessment often works, especially on small everyday matters, and Seneca and the Stoics are quite right, that it is well worth getting into the habit of automatic reassessment, which makes life much more pleasant.

Seneca, I believe, resisted the attempts of an earlier Stoic, Posidonius, who remains unnamed, to question the very intellectual treatment of emotions as the acceptance of evaluative appearances. Surely this is not how wordless music gives us emotions, or how animals experience emotions, and in any case disowning our first thoughts does not always free us of emotions. 'I have nothing to cry about', we think, but we are still distressed. That is what Posidonius had objected. But without naming him, Seneca dismisses all three of his examples as not cases of emotion, but only of the symptoms produced by appearances. Animals, listeners to wordless music, and those who disown their bad thoughts, experience not real emotion, but only irritating symptoms which do not really matter. Indeed, Seneca draws this conclusion not only for wordless music, but also for the arts as a whole. Painting, stories, spectacles, theatre, tragedy all produce mere symptoms, but not the mental acceptance that constitutes emotion. This, I suspect, is why Seneca did not feel he needed to discuss Aristotle's theory of tragedy, that it pleases us by lightening pity and fear, through first stirring them up in controlled circumstances. According to Seneca, theatre does not stir up real emotions at all.

All this is in 4 pages of On Anger, Book 2, section 1 to 4. And the contrast between mere symptom and true emotion was to have a huge effect on Christianity, which moved from a Stoic theory of how to resist emotion, to a Christian theory of how to resist temptation. The mere symptoms of the Stoics became for Christians the first titillations of temptation that were to be profoundly studied in the monasteries.

3. Porphyry On Abstinence from Killing Animals

I now come to a period of 400 hundred years from 200 to 600 AD, which Gresham College has helped me make more accessible by supporting the translation of its Philosophy. It was the period in which pagan Greek Neoplatonism arose and was slowly overcome by Christianity, while indelibly affecting it. There was a love-hate relationship between pagan and Christian philosophy, as we shall see. The second Neoplatonist was Porphyry, the pupil in Rome of the founder, Plotinus in the late 3rd century AD. Porphyry forever put Aristotle on the Western curriculum, by answering questions that had been raised about Aristotle's compatibility with Platonism. Writing just before Christianity became the religion of the Roman Empire, he questioned it in his Against the Christians, which was twice condemned to be burnt, and which, to the satisfaction of many modern scholars, redates one of the books of Old Testament prophecy, to show it was written after the events supposedly prophesied.

His beautiful book, On Abstinence from Killing Animals, gives an overall picture of Neoplatonist ideals, even though he did not persuade his fellow Neoplatonists to abandon the ritual sacrifice of animals and the tasting of their meat, practices which in the pagan era were inextricably linked. What Porphyry argues in 89 pages of translation, divided into 4 books, is that if you truly understood the nature of gods, animals and humans, you would not kill animals. Gods are not the sort of beings who can be pleased by our shedding the blood of their own property. Many human nations are successfully vegetarian, and this is much better for the control of emotions. Finally, you cannot agree with the Stoics that animals are owed no justice, because not part of the kingdom of rational beings, since animals are rational. Porphyry is unusual in recognising that we should be asking whether animals suffer, to which he says 'yes'. But the Stoics had made central the less relevant question, 'are they rational?' Porphyry's answer is rather charming. Animals understand us, and they even understand Greek, something that cannot be said of all humans, and he tells us of the partridge which he reared as a child, which adapted its vocal sounds to the young Porphyry. If you want to read just this part it is just the first 4 pages of Book 3, which itself is only 20 pages in all. But also important is Book 1, which records all the past arguments in favour of killing animals.

4. Augustine Confessions

The great Christian, Augustine, had read Latin translations of Plotinus when he wrote his Confessions around 400 AD, and of Porphyry, by the time he wrote the City of God after 400. He tells us in the Confessions, Book 7, that it was from the books of the Platonists that he learnt to look inwards into himself to find God. Platonism was the route by which he was first attracted to Christianity, and at first, he saw almost no difference between the two, but by the time of the City of God, he was aware of important differences.

To pick out a couple of the issues raised above, Augustine did not agree with Porphyry about sparing animals, despite the commandment, 'Thou shalt not kill'. Christ was a meat-eater, and Augustine therefore repeated only the anti-animal case of the Stoics, thereby influencing Christian attitudes to animals. On the other hand he did not like the Stoic belief in the perfectability of humans, as it manifested itself in the monastic view, inspired by the Stoics, that humans might be perfectable through their own efforts at resisting temptation.

In the Confessions, he tells in Books 1 to 3 the story of a sinful childhood, which he thinks illustrates the human condition: the infant's selfish crying, his own stealing of pears just for the pleasure of stealing, his visits to sex shows. But he also tells of his inconsolable sorrow at the loss of a friend who died. Humans cannot cope, unaided by God, as the Stoics supposed, with such loss, 4.4.9 - 4.11.16 (6 pages). He points out how memory of past pleasure can be a source of pain, while memory of pain endured can be a source of pleasure. Another mixed pleasure is pleasure taken in seeing tragedies. Any 'pity' felt cannot be, as Aristotle claimed, genuine pity, or people wouldn't enjoy seeing the tragedy over and over again. In Book 8, Augustine describes his own moral struggles in terms of opposing wills within him.

In two pages at Book 9, chapter 10 (23-6), Augustine describes the conversation he had with his mother a week before her death, in which they believed they had direct experience of God. Augustine wonders if what was momentary and interrupted for them would be the uninterrupted experience after death of the saints.

In Book 10, Augustine describes memory as a storehouse in which one stores not only images of things, as was thought by many, but also things themselves. It is in his memory that he finds God. But in Book 11, he takes up Aristotle's question whether any part of time actually exists, and he wonders whether past, present and future exist as states of mind: memory, expectation and present awareness. If so, it would become clear how the inhabitants of the heaven of heaven, discussed in the final two books, could actually escape from time by shedding memory and expectation. The saints, if they are included, are rapt in contemplation of God, with no memory of past life, or concern for the future, and so might have moved some way in the direction of God's more complete timelessness.

One translation of Augustine stopped after Book 9 when the juicy autobiography seems to stop. But actually, as the proportion of philosophy grows, Augustine is talking still about his past experience and his future hopes.

5. Philoponus Against Proclus On the Eternity of the World

For my last two books, let me skip to the 6th century AD, and start with the Greek-speaking Christian, Philoponus, who was steeped in pagan Neoplatonism. Christianity was now the dominant religion, and the pagan Neoplatonists were on the defensive. The leading pagan Neoplatonist in Athens in the fifth century AD had been Proclus, whose 'holier than thou' attitude had been a thorn in the side of the Christians, from whom indeed he had briefly had to go into hiding. Now in 529 AD two remarkable things happened. The Christian Emperor closed the pagan Neoplatonist school in Athens, while in Alexandria, Philoponus, speaking on behalf of the Christians, attacked Proclus' defence of the idea of a beginningless universe in his Against Proclus On the Eternity of the World. This is one text in which Philoponus repeats his argument that the pagans' denial of more than finite numbers requires them to give up their belief in a beginningless universe. Not only would the universe otherwise have finished going right through a more than finite number of years, but next year it would have gone through a more than infinite number. This is explained in three brief pages, 9-11. The Christian belief in a beginning must be right, on the pagans' own principles.

In the same work, Philoponus urges on his opponents the modern-sounding idea of matter as a field endowed with properties, rather than as the something-I-know-not-what that underlies properties, which John Locke was to attack so many centuries later. Elsewhere, Philoponus advocates new ideas in dynamics, including the impetus theory, which Thomas Kuhn believed to date from 800 years later and hailed as a scientific revolution. Philoponus unified dynamics by suggesting that all motion was due to various kinds of impetus, including an impetus instilled into matter by God at the time of the Creation. Gresham College has supported the translation of the first half of Philoponus' Against Proclus on The Eternity of the World, which will be published in two volumes later this year. I can already show you the title page.

6. Boethius The Consolation of Philosophy

My last book was written about 5 years earlier by another Christian who wanted to serve Christianity in an almost opposite way. The aristocratic Boethius held office in Ravenna under the Ostrogothic king. He wanted to translate Plato and Aristotle into Latin, and to supply Latin commentaries on them based on those written by the pagan Greeks. Philoponus too had started earlier in his career by writing Greek commentaries on Aristotle, while remaining content to expound Aristotle with very little Christian reservation. But Boethius had translated only some logical works of Aristotle, and written some commentaries on the logical and mathematical sciences, when he was accused on a political charge, and imprisoned for a year before being put to death with a cord tightened round his temples, at the age of around 45. The next 600 years in the Latin speaking world had little more of Aristotle than Boethius had given them, and it was left to the Islamic world to make the main advances beyond the Greeks.

In prison, Boethius wrote The Consolation of Philosophy, a short book in prose and verse, in which he asks whether life is governed by divine Providence, by chance, or by Fate, and what the relation is between these three. His account of chance is Aristotle's account of coincidence, but Providence turns out to be closely related. This beautiful book inspired two English sovereigns, King Alfred and Queen Elizabeth the first, to write translations or paraphrases, Alfred's being very much adapted for his own political purposes

The 5th and last book of the Consolation, 19 out of 119 pages in one typical translation, makes the most daring use of pagan Greek ideas. Boethius asks whether God's Providence would not imply his foreknowledge of everything, and hence imply that everything is inevitable in advance. His reply takes up ideas some of which will by now be familiar. God is outside of time. After all, on one view he created time, and so can hardly depend on it for his own existence. But if God is outside of time, his knowledge is not fore- knowledge, but timeless knowledge. This protects us from inevitability. God's foreknowledge would imply inevitability for two reasons. First, unlike human knowers, he is infallible, so nothing we do can make him wrong. Secondly, if he thinks in advance that people will do so-and-so, it is too late for anyone so to act that God thinks otherwise, because the past is irrevocable. Boethius' move questions not the infallibility of God, but the irrevocability of his thought. It is not too late so to act that God thinks accordingly, because God's thought is not in time at all. Boethius here is using the point made by an anti-Christian pagan Neoplatonist, Iamblichus, a pupil of Porphyry. The point was that knowledge takes its status from the knower not from the known. Knowledge of the indefinite can be definite, and in Boethius' example, knowledge of the temporal can be timeless.

The half dozen books chosen illustrate, I believe, how themes about freedom, coincidence, time and infinity, can be studied by Aristotle out of scientific interest, but taken up again by Stoics, Augustine, Philoponus and Boethius in the quite different context of questions about how to live, the human predicament and God.

The texts I have selected could be quite quickly sampled. In many cases, they are available with English translation in many libraries and in print in the Loeb Classical Library. I suggest you only stay with an author if you find the sample valuable, and otherwise try another author. Let me repeat the selection, with pages enough to provide a sample. Loeb pages are small, so more numerous. My next choice would be Plutarch Moralia, needed in every household with young people, best vol 6 in the Loeb series.

1. 4th century BC. Aristotle Physics (Sample, Book 2, William Charlton Physics 1 &2 in the Clarendon Aristotle translation series Oxford University Press 22 pages, or Loeb Physics vol 1 out of 2, 40 pages, or Complete Works of Aristotle revised, vol 1 out of 2, Oxford University Press, 12 pages).

2. 1st century AD Stoics

Seneca On Anger , in Loeb Moral Essays vol 1 out of 3

( Sample 2.1-4, 4 pages)

(See also his Epistles, 3 vols in Loeb, sample anywhere).

Epictetus Discourses Sample 1.1, Loeb vol 1 out of 2, 3 pages)

3. 300AD Porphyry On Abstinence from Killing Animals, tr Gillian Clark, Duckworth, General editor Sorabji, (Sample Book 3, 20 pages)

4. 400AD Augustine Confessions translated by Henry Chadwick, Oxford University Press, World's Classics. Books 1-11 are 243 pages, (Sample 23 pages for any one of these books that you choose).

5. 529 AD Philoponus Against Proclus on the Eternity of the World, first 8 books out of 18 to be published by Christmas 2003, tr Michel Chase, 2 vols, General editor Sorabji, Duckworth (Sample pp 9-11 of the Greek, in first vol, 3 pages)

6. 524AD Boethius, The Consolation of Philosophy (Sample Book 5, Loeb revised ed, 25 pages, tr Sharples with Cicero on Fate, Aris & Phillips, 17 pages)

The two biggest omissions from the list of 6 are Plato, whose Timaeus is the closest in subject to the other selections (translation with useful notes by Cornford, Routledge), and Lucretius On the Nature of Things for the fullest extant Epicurean view.

© Richard Sorabji