Aristotle - Study Notes
ARISTOTLE by Jonathan Barnes
Why are we studying a philosopher who lived nearly two and a half thousand years ago? Obviously things have moved on quite a bit since Aristotle’s time, and there has been considerable change and development within Philosophy as a subject since those far-off days. But Aristotle can rightly be regarded as one of the ‘founding fathers’ of the Western philosophical tradition, and that is probably as good a reason as any for studying his ideas, many of which have stood the test of time. The word ‘tradition’ can of course be somewhat misleading, suggesting that we follow old, established ideas simply because they are old and established.
But Western Philosophy is not actually like that – it is a critical activity, and it is remarkable for being critical of itself. Unlike Eastern Philosophy it is non-mystical; it is not beholden to established religious beliefs (or to any other sort of doctrine), and it gives greater emphasis to a more analytical, conceptual approach. It is also non-dogmatic. For example we can ask ‘what is justice?’, and the response of Confucius in ancient China would have been to lay down a set of didactic rules concerning what you must or must not do. But the response of Socrates, Plato or Aristotle to that question would have been very different. They took the question ‘what is justice?’ not as a request for a set of rules but as a request for a definition of the word ‘justice’, and they would have regarded that question as a starting point for a discussion or a debate. And the discussion they started goes on to this day.
The three big names in ancient Greek philosophy were Socrates, Plato and Aristotle. Socrates lived from 470 BC and he never wrote anything, but Plato, his most famous associate, did, and quoted Socrates throughout his writings. Socrates is notable for his well-argued views on various topics but also for introducing certain basic principles into philosophical and any other form of discourse. For example, the importance of defining complex terms. If people are discussing for example justice or freedom but have in mind different definitions of justice or freedom, their discussions will very likely be ambiguous and at cross purposes. So they need to discuss their definitions first. Socrates also perfected the method of inducing people to draw conclusions for themselves. For example if people know that all men are mortal and are then informed that Socrates is a man, they should then be able to deduce of their own accord that Socrates is mortal without further proof or explanation being necessary. Socrates taught reasoning, albeit informally.
Plato, born in 428 BC, was closely associated with Socrates and reiterated much of what he learnt from Socrates in his various writings. Famous for his political philosophy as set out in The Republic, he taught at the Academy which he established in Athens. We’ll be encountering some of Plato’s ideas as we study Aristotle who was one of his pupils.
But let’s get on with Jonathan Barnes’ book on Aristotle.
Chapter One, The Man and His Work, gives a brief introduction to Aristotle. Born in 384 BC, he died in 322 BC at the age of 62; he had been a scientist, a philosopher, a teacher and a public figure. He came from a rich family; he was a good speaker, witty, persuasive and lucid. His major desire, throughout his life, was for knowledge and for truth. He saw this as the purpose of his life.
He wrote a large number of books, over 50 volumes, on metaphysics, ethics, justice, the soul, pleasure, science, deduction, definition, political theory, history, rhetoric, motion, astronomy, logic, language, law, psychology, mathematics, philosophy of science, space and time, and theory of knowledge. Only a fifth of his writings has survived. Many of his writings were probably lecture notes.
Chapter Two, A Public Figure.
Aristotle was not a recluse, far from it. Before retiring to an island he had spent the previous thirteen years in Athens where he had taught at the Lyceum. The Lyceum was not a university; there were no fees, exams or degrees. It combined teaching and research which Aristotle carried out with his pupils as a team. He left Athens because Macedonia, further north, was very unpopular with the Athenians in those days and although Aristotle had not been a Macedonian ‘agent’, he had been associated with Macedonia previously and found it prudent to leave as events developed.
Chapter Three, Aristotle’s Zoological Researches.
Between 347 and 335 BC, Aristotle did research in the field of Marine Biology which established his competence and enduring reputation as a scientist. He also made observations in astronomy, meteorology, chemistry, physics, psychology and other sciences, but his scientific fame rests primarily on his work in zoology and biology which was not superseded until 2000 years after his death. He worked on the islands of Assos and Lesbos, and produced two large volumes, the History of Animals and the Dissections. His work was detailed, wide-ranging and comprehensive; of course, he occasionally made mistakes such as omissions and errors of methodology. But his work made it abundantly clear that knowledge can only be based upon evidence and observation, and not through any other source. We’ll come back to this point later.
Chapter Four of Barnes’ book is entitled ‘Collecting Facts’.
Obviously Aristotle could not have based his scientific writings solely on research he had carried out himself single-handedly. That would have been impossible. He could only and inevitably have borrowed and reproduced the observations of others; and this, he maintained, was the only way to start and proceed. But this is not the same as plagiarism. He said of course you must make full use of the work of others. To do otherwise would be silly; it would be superfluous to repeat work that has already been done. Obviously you should acknowledge the work of others; and it is equally important not to accept the work of others uncritically. Of course, Aristotle still had to do a lot of his own research; this is virtually the whole of what he did in Logic, which we’ll come to later. But otherwise, he stressed the importance of trusting ‘reputable opinion’ as he called it (or else you’d be re-inventing the wheel all the time).
Chapter Five is “The Philosophical Background”.
As we have seen, Aristotle as a scientist was a ‘collector of facts’, but there is nothing particularly ‘philosophical’ about collecting facts. Aristotle was also, however, a philosopher. At the age of 17 he went to Athens and studied philosophy at Plato’s Academy. And Plato was (and still is) a philosopher of note who concentrated primarily on philosophical questions, for example metaphysics, theory of knowledge, logic, ethics, political theory etc.. Aristotle first made a name for himself in rhetoric, the study of how to argue persuasively. But Aristotle could also see that rhetoric is not the same as logic – an argument can be persuasive but may yet be erroneous in its logic. He therefore began to develop a ‘catalogue of fallacies’ which he taught to younger students, and Barnes goes into more detail about Aristotle’s work on logic a little later.
Returning to ‘philosophy proper’, Barnes summarizes some of the similarities and differences between Plato and his pupil Aristotle. Firstly Plato saw science not as the random amassing of facts but as the organization of facts into a coherent account of the world. Aristotle entirely agreed. Secondly, Plato emphasized the role of consistency and coherence in discourse and argument. So did Aristotle, but it was Aristotle who was the first logician and who first identified and formulated specific logical rules. Thirdly, Plato was concerned with ontology, this being the study of what really exists. For Plato, the ultimate ‘reality’ consisted of ‘abstract universals’ (such as ‘sheep’, ‘mountain’) which have a subsistent ‘existence’ behind appearances, a notion which is to say the least difficult to understand let alone to explain. Aristotle did not accept this aspect of Plato’s thinking. Fifthly, however, both Plato and Aristotle agreed that knowledge itself raises philosophical problems. What is it to know something, and how can knowledge be differentiated from belief?
Chapter Six, The Structure of the Sciences, is unavoidably rather technical.
The most developed of the Greek sciences was geometry, and the most famous name in this field was Euclid. Although Euclid worked after Aristotle’s death, his predecessors had prepared the groundwork which Aristotle was familiar with. The basic idea is that you start with a small number of simple, unproved intuitively obvious basic principles which are called axioms. For example, ‘the shortest distance between two points will be a straight line’. From the axioms you then derive, by purely logical deduction, all the other truths of geometry. These are called theorems, and each theorem follows logically from one or more of the axioms. Logicians call this an ‘axiomatized deductive system’. You can put it on a computer.
Plato suggested that the whole of human knowledge might (somehow) be set out in a single axiomatized system – from a small set of primary truths, the axioms, every other scientific truth might be logically deduced. Aristotle thought this was over-optimistic, for he noted that different sciences would, surely, require different axioms. For example geologists and doctors work in entirely different domains and discuss different objects with different methodologies; their disciplines rarely overlap. But Aristotle nevertheless agreed that some form of systematization was necessary – human knowledge may not be ‘unitary’ as Barnes puts it, but nor is it a ‘disconnected plurality’. The conceptual apparatus and the formal structure of the sciences are basically the same (all are based on observation, for example).
Aristotle divided knowledge into three major classes – the practical, the productive and the theoretical, and on p45 Barnes provides a diagram of how Aristotle saw the structure of human knowledge. It seems cogent and rational; one possible update I’d mention would be to place a dotted line between logic and mathematics. This is because in the nineteenth and twentieth centuries the German mathematician Frege and the British philosopher Bertrand Russell sought to derive mathematics from set theory which is a branch of modern logic.
In Chapter Seven Barnes looks at Aristotelian logic.
Logic is a very complex and technical subject and we can only give it a very brief glance. But Aristotle is noteworthy for having formulated it symbolically using letters to stand for objects, together with rules of valid inference. For example, if all A’s are B’s and if all B’s are C’s, then it is necessarily true that all A’s are C’s and we don’t have to make separate observations or tests to find that out. This simple inference is called a syllogism, and it holds true whatever subject matter the A’s, B’s and C’s stand for, just as in maths the formula 1+1=2 is always true whether you’re counting apples, pears, or dollar bills. Of course, mathematics is considerably more complex than simply saying 1+1=2, and the full elaboration of Aristotle’s syllogistic logic is likewise much more complex than the simple example we have just given. Aristotle’s logic can rightly be regarded as one of the greatest achievements of the human mind, and the work he did on logic was not superseded until the time of Frege and Russell (who did not, incidentally, reject Aristotle’s logic, they developed it further). In modern symbolic logic there are theorems, proofs, formulae and so forth and it is very technical.
Chapter Eight, Knowledge, deals not with how to derive the theorems of a science from its axioms but the status of the axioms themselves.
In other words, what is the basis and justification of what counts as knowledge? Firstly, and obviously, for something to count as knowledge it must be true. Also, an axiom must be ‘immediate and primary’, otherwise it must depend upon the truth of other axioms which must then be justified themselves.... but how far does this go on? Aristotle’s overriding condition for something to count as knowledge is the condition of causality. To explain why something is so is, obviously, to cite a cause. But this seems odd, for two reasons. As Barnes points out, you can know something perfectly well without knowing anything at all about its cause, for example you can know that World War Two broke out in 1939 without knowing why it broke out. Secondly, the causality condition leads in theory to an infinite regress. If I know X, then according to Aristotle that means I must know its cause which we could call Y, but then I would have to know the cause of Y in turn and so on forever and ever! But Aristotle would probably have rejected these criticisms as merely trite, pointing out that although complete knowledge of something is only possible if you understand its cause, it does not follow that we have to go back into time forever and ever. Sufficient understanding of something is usually attainable long before then.
The second condition for ‘knowledge’ is that something is ‘necessary’, meaning that it could not have been otherwise. But surely there are plenty of true facts in our everyday life which ‘could have been otherwise’ (too many of them, some might say!). But here again Aristotle would simply have rejected that criticism. What I’m sure he meant was that when you’re in possession of all the relevant facts relating to an event or situation, you can understand how it could not have been otherwise and therefore your understanding of it is complete.
Chapter Nine, Ideal and Achievement.
Aristotle is, or purports to be, a systematic thinker. The sciences are autonomous, but inter-related. Each individual science is to be developed and presented in the form of an axiomatic system. But we encountered problems when we come to the detail, as we found in Chapter Eight – in one situation or another, our knowledge can be theoretically incomplete for various reasons. Some scholars, therefore, have disputed the view of Aristotle as ‘systematic’. On the contrary they see him as a piecemeal worker, addressing problems ad hoc. Personally I flatly disagree, as does Barnes. Aristotle would have said of course you have to be ‘piecemeal’; if you don’t take a careful, step-by-step approach you’ll get nowhere and you’ll make mistake after mistake. To be systematic means to take a piecemeal approach – if you want to put it that way.
Chapter Ten, Reality, is quite a difficult chapter.
Science is about real things which is what makes it knowledge rather than fantasy, but what things are real? Plenty of things, but the class of substance seems to be primary for without it there could be no such things as for example attributes or relations. The notion of distance is real enough, but it is not a thing, it is a relational concept. It would not even make sense if there were no things, or substances which can be near to or far from each other. In that sense, substance is primary. If we had unlimited time at our disposal we could go into all the ins and outs of Aristotle’s reasonings about substance, but we don’t so we can’t. We can only state what seems to be Aristotle’s final answer to the question of what is substance, or what is real, which is very simple – namely, perceptible, middle-sized material objects. And Aristotle asks how can there be any substances apart from perceptible, material substances?
Chapter Eleven, Change, is also somewhat complex. One of the most important features of Aristotle’s ‘middle-sized material objects’ is that they change, and Aristotle identifies four types of change. Things can change in respect of substance, quality, quantity and location. Change in respect of ‘substance’ is coming-into-being and going-out-of-existence; a living creature is born, and later it dies. Change of ‘quality’ is called alteration, as when a plant grows green in sunlight and pale in darkness. Change in ‘quantity’ is ‘growth and/or diminution’, or change of size as when a sapling becomes a tree. Change in location would imply concepts of distance and speed.
Aristotle’s Physics studies change in its various different forms. Change always involves three things: the state from which the change proceeds; the state to which it proceeds, and the object which persists through the change. This third item is probably the most puzzling. It seems absurd to say that Socrates as an entity ‘persisted’ through his birth and through his death; we simply say that these two changes marked the beginning and the end of his existence. Aristotle acutely observes that substances, material bodies, are always composites. A house consists of bricks and timbers arranged in a certain structure, so that things consist of two aspects, ‘stuff’ and structure, or matter and form, and their re-arrangements if any is how we account for and understand change. Of course, that puts it very simply, but it seems to be the essence of Aristotle’s account of change.
Chapter Twelve, Causes, gives us evidence once again of Aristotle’s systematic approach.
In Aristotle’s view, to ask what is the cause of something is basically to ask why something is the case. A question ‘why?’ requires an answer that starts with the word ‘because...’. Barnes’ account is somewhat complex, but Aristotle analysed the concept of causality into four components:-
(i) the material cause;
(ii) the formal cause;
(iii) the efficient cause and
(iv) the final cause.
These are best explained by an example – why does a statue exist with all its various attributes and its pleasing appearance?
(i) Because it consists of marble, for example, which is the material cause.
(ii) Its shape is because it was designed that way: the formal cause.
(iii) The efficient cause is because it was made by a skilled craftsman.
(iv) Its purpose, the final cause, is to provide adornment in for example a living room.
These four concepts, to varying degrees and permutations, enable us to understand causality.
Chapter Thirteen, Empiricism – a very important word in philosophy.
Nothing to do with empires, empiricism is the thesis that all knowledge of matters of fact is (or must be) based upon observable evidence and not through any other source. Conjecture, intuition, speculation, guesswork or the exercise of imagination are ruled out as sources of knowledge. Deductive logic is not the answer either, for all that logic does is to draw conclusions from premises – but how are the premises known to be true in the first place?
Aristotle was not an armchair theorist; he was a ‘hands on’ scientist himself, so – arguably – he knew what he was talking about when he said that knowledge can only be based upon observable evidence. In his view the ultimate source of knowledge is perception, that is, what we perceive through the five senses: sight, hearing, touch, taste and smell. But perceptions do not in themselves constitute knowledge; knowledge is only arrived at when repeated perceptions are memorized and compared, building up into experience which finally coalesces, so to speak, into knowledge.
Of course we can query whether sense-perception as it is called is reliable, and certain perceptions such as reflections or mirages can deceive us. Aristotle would simply have said that it doesn’t follow from reflections or mirages that our perceptions always deceive us. But a more complex problem which must be taken seriously is the question of drawing general conclusions from a limited number of observations. This is particularly the case when formulating complex theories or hypotheses, and present day philosophers of science address these issues in some detail.
Chapter Fourteen summarizes Aristotle’s World-Picture.
His scientific work and his philosophical investigations were, as Barnes puts it, the two halves of a unified intellectual outlook. The physical world consisted of four basic elements, earth, air, fire and water – somewhat naive by our standards, but at least Aristotle had made a start, in those far-off days. This was, after all, millennia before the age of modern chemistry. In Aristotle’s cosmology, the earth was at the centre of the universe. He seemed to reject the orthodox Gods of Ancient Greece such as Zeus and Athena, but in his Physics he argued for the existence of a ‘unmoved mover’ outside the universe. It is not clear, however, how he would have reconciled this idea with his empiricism (or the question of how we, in the universe, can know anything at all about something outside it).
Chapter Fifteen, Psychology, is very brief.
An important distinction within the natural world is that some entities are alive and others are inanimate. What distinguishes living creatures is that they possess what the Greeks called ‘psuche’, meaning ‘soul’ or in less complex creatures, ‘animator’. In addition to basic animation the more complex creatures possess perception, appetite, reproduction, desires, fears and, in the higher animals, thought and (presumably) knowledge. In Aristotle’s account souls are not bits of spiritual ‘stuff’ placed inside physical bodies, as Barnes puts it, they are more akin to powers, capacities or faculties. Thus Aristotle adroitly avoids the problems that confronted Descartes in the 17th Century who tried, unsuccessfully, to reconcile having a physical body but a non-physical soul in one and the same person. To Aristotle, a ‘soul’ was not a ‘thing’ at all, or so it would seem on Barnes’ account.
Chapter Sixteen, Evidence and Theory.
It is of course true that other than his pioneering work in Zoology, Aristotle’s general account of the world and the universe is false, sometimes absurd. But in fairness to him he was literally beginning at the beginning. It was not until the sixteenth and seventeenth centuries that quantitative methods began to be applied to science, and chemistry and physics came to be predominant. Aristotle failed to develop ‘a decent chemistry or an adequate physics’, as Barnes puts it, but he did not have our modern concepts of mass, force, velocity or temperature. He could not measure temperature for the simple reason that thermometers were not invented until the 17th Century. Likewise he had no modern laboratory equipment, nor did he have higher mathematics which would have been needed for physics (differential calculus was not invented until 1665). It is unfair to blame Aristotle for his shortcomings in some of the sciences.
Two criticisms against him are that he regularly subordinated fact to theory, and that he seemed determined ‘to find plans and purposes in the world of nature’. Barnes refutes the first accusation by quoting evidence to the contrary in some detail, and in Chapter Seventeen Barnes addresses the second accusation.
The title of the chapter, Teleology, derives from the Greek word telos which means goal or purpose. And Aristotle did indeed have a teleological view of nature, but this does not mean he thought that ‘nature’ had intentions or plans. What he meant was that in order to explain many natural phenomena we must refer to teleological explanations. For example, why do ducks have webbed feet? In order to swim, and to say this is not to impute to nature any sort of conscious design, it is a purely functional explanation of how ducks operate within their watery environment.
In Chapter Eighteen, Practical Philosophy, Barnes manages to summarize Aristotle’s ethical philosophy and his political philosophy into just eight pages of a small book. The most I can do is to give a summary of a summary so it’ll be nothing more than a snapshot, a pretty blurred one at that. Aristotle wrote two ethical works, the Nicomachean and the Eudemian. Aristotle’s ethics take a very different approach from that of moral philosophers of the present day. Modern philosophers tend to be preoccupied with definitions, semantics and the meaning of ethical terminology, often criticized for being so abstract as to be barren. Most people who approach ethics as a subject are more concerned with practical issues such as moral dilemmas, and don’t want to be plunged into moral semantics exclusively.
Aristotle’s approach is refreshingly different. No doubt he’d have been as concerned as any other moral philosopher with the precise meanings of words, but his primary concern was to identify and describe which modes of behaviour are distinctively ethical modes of behaviour. Or to put it another way, what modes of behaviour are morally required? He speaks of being successful, but by this he does not mean getting promoted at work or making a lot of money in your career. He means being excellent in one’s character and in one’s intellect, including such virtues as courage, generosity, fair-mindedness, knowledge, good judgment and genuine friendship. And as human beings we should think reflectively and reason about these modes of behaviour too.
Moving on to Aristotle’s politics, he maintains that we are by nature ‘political animals’, but he says this not as an aphorism but as a piece of biological theory which is literally true. It is as natural for human beings to live in societies as it is for fish to live in water, and it is likewise natural for there to be social rules of some sort or another. But what rules should these be? Barnes’ account is unavoidably brief, but it seems that Aristotle preferred democracy as a mode of government. This did not seem to apply however to slaves who, under Aristotle’s scheme of things, would have no liberties or rights. The state, in Aristotle’s view, should regulate the lives of citizens in some detail, so his state is ‘highly authoritarian’, as Barnes puts it. In fact Barnes goes on to remark that the ‘infant voice of totalitarianism’ is to be heard within Aristotle’s writings. On the other hand you can level this criticism at more or less anyone at all who says that authority or discipline are needed in human societies.
Chapter Nineteen, The Arts, is extremely brief.
Aristotle had a lot to say about poetry, literary criticism, tragedy, drama, music and the fine arts.
Chapter Twenty, Afterlife, is Barnes’ summing up of Aristotle as having had the most profound influence on human thought for over 2000 years. He founded not one science but two – biology and logic, and for centuries he was regarded as being the ‘last word’ on those subjects. During the Middle Ages his philosophy and cosmology were carefully integrated with Christian theology by St. Thomas Aquinas, and for centuries Aristotle was simply referred to as ‘the philosopher’.
But as Barnes points out, Aristotle was also responsible not only for what we thought but also for how we thought. And this survives today – as Barnes says, ‘our modern notion of scientific method is thoroughly Aristotelian. Scientific empiricism – the idea that abstract argument and theory must always be subordinate to factual evidence – now seems a commonplace.’ A few thinkers since Aristotle’s time seem to have forgotten that, but let us not digress.