Let me begin with an image. It is of an old-fashioned beam balance of the sort that blind Justice is often portrayed as holding. Its very appearance tells us what it is to be accurate. What I want you to imagine is that part of your visual system is like such a balance. When you discriminate colours correctly, it tilts just the right amount; when you discriminate them incorrectly, it tilts too much or too little. When it is generally in the first condition, so that you do discriminate colours correctly, Aristotle says that it is in a ‘perceptual mean’.

Imagine that your other senses are like that too. If the relevant part of each was in the mean, they would all be good and accurate discriminators of colours, sounds, tastes, smells and feels. Now imagine each of those five small balances registering their tilts, their inputs, with one large central balance (roughly what Aristotle calls ‘the common sense’). It constructs out of them a multisense picture of the three-dimensional world of objects that are coloured, make sounds, have tastes and smells, textures and temperatures, occupy places, and trace out continuous spatiotemporal paths, as they move around causally interacting with each other and ourselves. This is the world of substances – ousiai as Aristotle calls them. You, their perceiver, are also one of them.

When we perceive white, and our colour perceptual system is in a mean, our perception is quite reliable, but when we perceive that the white thing ‘is this, or something else, error is possible’. In these cases, the ‘this, or something else’ is a coincidental perceptible, such as the son of Cleon, whom we perceive ‘not because he is the son of Cleon, but because he is white, and the white thing is coincidentally the son of Cleon’. It is a person’s perception of coincidental perceptibles that fear or some other appetite or feeling can distort, so that he ‘seems, even from a very slight resemblance, to see his enemy’ or, if he is in love rather than in danger, his beloved.

The perceptual apparatus thus interacts with the motivational apparatus, with our appetites, feelings, emotions and desires. And it is this fact that brings the more familiar mean – the one we encounter in Aristotle’s Nicomachean Ethics in connection with the virtues of character – on to the scene.

Let us consider, for simplicity, one such virtue: courage. It is related to feelings of fear and confidence in the face of danger. To be overly afraid of small dangers is to be cowardly, while to be overly confident in the face of large dangers is to be rash or foolhardy. To be courageous, by contrast, is to have one’s fears in a mean, so that they measure dangers correctly, with the result that one’s feelings of fear, and the actions they cause and motivate, are correctly responsive to the dangers one faces. Similar considerations apply to other feelings and actions. Temperance, for example, is concerned with the pleasures and pains of appetitive desires, such as those for food, drink and sex. It is pleasures and pains of various sorts, indeed, that are the foci of the virtues of character in Aristotle’s view.

Let us think of the virtues of character as, on the one hand, filters, since they filter out, or counteract, the distortions that our desires introduce into our perceptions. On the other hand, we can think of them as lenses that, now cleaned of distortions, reveal the world of values to us, as it really is – in the same way that the perceptual mean reveals, for example, colours. Hold on to that idea: the virtues of character reveal the world of values to us, a world that disorderly desires make invisible. In the Republic, Plato tells us that the allegory of the cave illustrates the effects of education on us. An education does not put sight, or intelligence, into blind eyes, but turns us around to face the Sun and the good by cutting the bonds of desires that keep us in darkness, focused on mere distorted images of the good, rather than the good itself.

For Aristotle, the virtues of character are not enough by themselves to work the magic of illumination that comes with exiting Plato’s cave. We also need the intellectual virtues: practical wisdom (phronêsis) and theoretical wisdom (sophia) – the latter being what philosophia is the love of. After all, to calibrate our desires, to set their balances in the right mean, we have to know what our good really is, and that involves knowing what we really are. And not only that: but of what sort of world we are a part.

In his Nicomachean Ethics, Aristotle imagines all bodies of knowledge organised into a pyramid, with politics, or political science (politikê), at the top, on the grounds that it is the science with the most authority. It both decides which sciences should be part of the city or polis (part of the curriculum in a publicly funded university), who should study them and to what extent (who should be admitted to university and who should teach there), and how their diverse outputs should be employed to further the common good. The mark of a correct, as opposed to a deviant, constitution or political system is that its laws and everything else are organised so as to promote the common good, not that of the ruling class.

Of course, the politician (in the sense of the one who knows Aristotle’s political science) cannot have expert knowledge of all of the subordinate sciences in the pyramid of sciences. Even G W Leibniz, the last person to know everything, didn’t know that! So how is the politician to avoid being hostage to experts, whether genuine or pretender?

Let us go back for a moment to the virtues of character. These virtues ensure that a person is free from subservience to desires that distort his perception of the good (as revealed by the various sciences) and cause actions and behaviours that fail to embody that good. When we add the knowledge of what the good actually is, the person now has not just the virtues of character but also the intellectual virtue of practical wisdom.

However, practical wisdom, Aristotle tells us, is the same state of the soul as political science, differing from it only in its orientation: practical wisdom looks to the good of the individual; political science to the good of the city. But since human beings are political animals – animals that do well in life only as part of a political community – the two orientations necessarily overlap.

Focus now not on our being hostage to desires that have the potential to distort our perception of values but on our being hostage to scientific experts who have the potential to distort our knowledge of what is really good for us. The virtues of character free us from the first, provided that practical wisdom frees us from the second. But how is practical wisdom to do that?

It is here that the well-educated person enters the picture. This is someone who studies a subject not to acquire scientific knowledge of it but to become a discerning judge: ‘Not being well-educated is just the inability to discern in each subject which arguments belong to it and which are foreign to it,’ says Aristotle. Thus a person well-educated in medicine, for example, is capable of judging whether someone has treated a disease correctly, and the ‘unconditionally well-educated person’, who is well-educated in every subject or area, ‘seeks exactness in each area to the extent that the nature of its subject matter allows’.

Philosophy, in fact, is what provided this unified vision of self and world

The most illuminating element in Aristotle’s description of the well-educated person is that he (in Aristotle’s writings it was always a he) knows the defining marks by reference to which we can appraise a science’s way of explaining things, separately from the question of what the truth is, whether thus or otherwise. That is, marks that enable us to determine whether a claimant to the title of the relevant science is the genuine article, without our having to know whether what it tells us is in fact true. The genuine sciences, after all, are our best routes to the truth. So our best route to which sciences are genuine cannot be through our science-independent knowledge of what the truth actually is. (Some religions, of course, deny this in some cases.)

In part on the basis of his own deep (often first-hand) knowledge of the sciences of his day, Aristotle was confident that the sciences all employed the same basic explanatory notions (final, formal, efficient and material causes, and the same logical structure). In an important sense, then, they all spoke the same language – a language that a well-educated person could learn. It was this, in part, that enabled him to see as a whole the world that each of the special sciences provides no more than a partial vision of, and to see himself and his place in it. Philosophy, in fact, is what provided this unified vision of self and world.

Is the idea of such a person – of an Aristotelian, well-educated person – still a real, or achievable possibility? I want to approach that question via a challenge posed by Elijah Millgram in his book The Great Endarkenment: Philosophy for an Age of Hyperspecialization (2015). Millgram’s central idea is that disciplines have become so hyperspecialised, each with its own technical vocabulary, tools, explanatory strategies, standards of exactness and success, that no one, however well-educated, could hope to have any worthwhile understanding of all of them. We live in a Tower of Babel, in which the epistemic autonomy needed for responsible democratic citizenship is, and can only be, an illusion. We are, and can only be, at the mercy of experts – when, that is, we are not simply in the grips of some sort of ideology, whether peddled by a religion, a corporation, a political party or some favoured website or other.

Let us return to Aristotle and to the idea of the pyramid of the sciences. We should enlarge the pyramid with bridging skills (to call them that), the aim of which is to transmit the knowledge of some science in a usable form to politicians and to citizens more generally. A good physics journalist (or physics populariser) does this. It involves being able to read real physics and being able to talk to physicists not with the aim of doing physics oneself, but with the aim of being able to translate into ‘ordinary terms’ what the physicist has to say in his technical and expert terms (terms that one must be an initiate in to understand). Bridge-physics is a real skill and an immensely important one. Replace physics with climatology and bridge-physics with bridge-climatology and you can see why.

Philosophy, even if not quite in the shape of a science of being as a whole (or metaphysics), as Aristotle thought of it, surely has an important role to play here. Philosophy helps us to achieve some reasonably informed overall pictures of reality and our place in it, and some of the analytical skills needed to undermine false pictures. But since academic philosophy, somewhat to its shame, has become as fragmented as the other sciences, what we would need, to continue the metaphor, is a bridging philosophy, informed by the specialised philosophies, and instilled with their respect for rigour and clarity, but more catholic in scope and intended audience, and so written in a language that any reasonably well-educated person can understand and respond to with interest. Edith Hall’s book Aristotle’s Way (2019), which is a joy to read, achieves something close to this in the case of Aristotle’s thought. But, as the 19th-century German philosopher Arthur Schopenhauer put it, when frustrated by the obscurity of Hegel’s writing:

Nothing is easier than to write so that no one can understand; just as, contrarily, nothing is more difficult than to express deep things in such a way that everyone must necessarily grasp them.

So bridging-philosophy itself requires special education and training, a special skill and caste of mind. Aristotle himself seems to have tried his hand at this sort of philosophy as well in his so-called exoteric works (of which only fragments remain), and to have succeeded rather well, since their prose, Cicero tells us, ‘flowed like a river of gold’.

But bridges, like chains, are no better than their weakest link. And in the case of the pyramid of knowledge that I’ve described, this link is undoubtedly that of the citizens and especially the citizen-politicians that in democracies are their representatives.

So now we come to another Aristotelian view, which is about education. It should, Aristotle tells us, be public and developed with an eye to the constitution (the political system) it is preparing students to be citizens of. It should equip students to be free citizens (free of subservience to their desires, free from subservience to experts, genuine or bogus), which will involve studying the constitution, but also its rivals, since in various ways it might fail to be correct – fail to promote the common good.

It should also be one that enables people to live well, to live a good life, in the society they belong to. And this is a matter of providing them with whatever is needed to access in the appropriate way the good things without which life is impoverished. Music (knowing how to read music, play an instrument, listen sensitively and perceptively), literature (knowing how to read with understanding, and be appropriately responsive to, the great poems and novels in one’s own language, and in that of others), and painting and film, similarly.

In the sciences, it is the same. Students need (and now I’m thinking about ourselves, not ancient Greeks) the kind of knowledge of mathematics that makes its nature and beauty accessible, and that provides the competencies needed, for example, to read a credit agreement, understand statistics and probability theory, so as to avoid being exploited. And they need the sort of understanding of physics, biology, psychology, sociology, economics and so on that will let them see how these sciences work, what their sensitivity to evidence entails, and in what way they reveal the wonders and complexities of the natural and the social world to the understanding eye.

Courses in the philosophy of some of these sciences, coupled with a more in-depth exposure to some of them, might achieve this. Here is Timothy Williamson, professor of philosophy at the University of Oxford, writing on the topic in the New Statesman magazine earlier this year:

Accurate, effective reporting of science must be honest about the nature of the scientific arguments without losing the reader in technicalities. Achieving even an elementary understanding of the science requires distinguishing three dimensions: its subject (such as the past, present and future climate), evidence about the subject (such as measurements of temperature), and theories about it (such as a hypothetical mechanism for global warming). To confuse any two of these three dimensions leads to alarming mental muddles, in which no theory lacks evidence, or nothing happens unobserved, or a change of theory is a change of climate. In other words, public discussions of science had better avoid basic mistakes in the philosophy of science, on pain of distorting scientific discoveries and their practical impacts. Accuracy in reporting science includes accuracy on these philosophical matters.

An education, scientific or otherwise, that aims at giving us the sort of understanding of the things that bear on the freedom and richness of our lives as citizens of complex societies and of the world is going to be very different from what we now have.

A part of Aristotle’s picture that has not yet been revealed, however, can come as a bit of a shock, and is too often ignored by contemporary ‘virtue ethicists’ who look only at the Nicomachean Ethics and not at its companion Politics. It is this: people do not develop practical wisdom until they reach the age of 50 or so, by which time their exposure to ‘theory’ has been leavened by their experience of the so-called ‘real world’. Aristotelian education, like its Platonic predecessor, is almost lifelong.

Part of what made this possible is that the constitutions Aristotle considered best afforded their citizens the leisure needed for lifelong education (wars and the like permitting – for the males all served in the armed forces), and for the happiness-promoting use of that education in accessing genuinely worthwhile goods, by having all (or most) of the labour done by slaves. From an educational point of view, this meant that there was no need to have education prepare students for the work world, so that they can become ‘productive’, employed members of our society, something we now (somewhat short-sightedly, in my view) assign to education as its major function. This is one major difference between Aristotelian societies and contemporary ones. But the day could well come in which robots play the role that slaves did in the ancient and not-so-ancient world, making the wise and rich use of leisure a more important educational goal.

Another major difference is that the societies Aristotle considers are also for the most part ethnically, culturally and religiously homogeneous. This makes invisible to him many of the sources of political faction and instability that are now at the centre of our political lives – along, to be sure, with the degradation that capitalist consumerism has inflicted on the natural world, on the social world and the world of international politics. Were we not so addicted to consumption (and the climate emergency might yet cure our addiction), perhaps we could imagine returning to self-governing political organisations that were more like Aristotle’s. Like the polis or city-state that Aristotle favoured, small nation-states, large nation-states and international political communities such as the EU are all ‘experiments of living’ as John Stuart Mill called them in 1859, and no one really knows which, if any, is best-suited for human flourishing. When happiness is measured in terms of income (GDP per capita), healthy life expectancy, social support, freedom to make life choices, trust (absence of corruption) and generosity, the happiest countries in 2018 were Finland, Norway, Denmark, Iceland, Switzerland and the Netherlands. So maybe Aristotle was on to something.

Aristotle held the idea that there is a permanent recipe for the best life and that, once we find it, all we have to do is keep to it

A third difference is that Aristotle’s favoured political communities were also – in a way that has huge import for democratic (or want-to-be democratic) societies – legally fairly simply making the need for lawyers, and issues associated not with equality under the law but with equal access to the law and to legal representation, much less pressing than they are in many of our societies, where gross economic inequality often cashes out as gross legal inequality.

A fourth difference is that Aristotle thinks of us as having a limited number of fixed social identities based in our natures: male, female, free, slave, citizen, farmer, craftsman, hired workman. We, by contrast, are less likely to think that our natures are quite so fixed as that, at least in the cases of our social or economic class or the sort of work we do. And related to the issue of identity is the notion of a biographical or narrative life within which that identity (or those identities) are realised. By thinking of free male lives as having one narrative structure – and that a political one – Aristotle, without realising it, narrows the set of male virtues or excellences to political ones. Similarly, by thinking of female virtues as having a domestic narrative structure, as realised exclusively in the domestic sphere, he narrows the set of female virtues to domestic ones.

We might agree with him, of course, that many of these virtues are virtues that any human being would need (courage, temperance, justice) but others he explores, such as magnificence and greatness of soul, seem more specific to a particular society, a particular narrative. Our life narratives are very broadly divided into our public lives and private lives, work and leisure. But the virtues needed in these two spheres are somewhat different and somewhat incompatible. In an antiquated popular psychology version of the story, the male (from Mars), in being hardened for the cut-throat world of work, becomes so distanced from his feelings that he soon cannot access them, finds himself when he gets home from work facing a woman (from Venus, in that same story) who wants him to share his feelings with her in intimate conversation. The virtues needed for competition now encounter the lack of the virtues needed for intimate exchange.

The final difference (of course there are others that I am not considering) between Aristotle and ourselves bears on what I call closure – on the idea that there is a permanent recipe for the best life and that, once we find it, whether in heaven or on Earth, all we have to do is keep to it. (As an aside: on the topic of heaven, I can’t resist quoting a short entry from the wonderful Journal of Jules Renard (1906): ‘I can believe anything, but the justice of this world does not give me a very reassuring idea of the justice of the next. I am very much afraid that God will go on blundering: he will receive the wicked in Paradise and hurl the good into Hell.’)

Such worries about heaven aside, on Earth closure is something we can no longer credit. For the vast collection of sciences and science-like bodies of knowledge that are our best guides to the truth about the world are constantly evolving, constantly modifying themselves, replacing old pictures with new ones. Closure – the end of science, the final picture, the (ominous) final solution – is inconsistent with what the history, sociology and philosophy of science (which are themselves science-like bodies of knowledge) tell us. It is one of the vices of ideology (political, religious or whatever) that it offers us the bogus comforts of closure in the shape of certain and final solutions, a final story of ourselves. We might see in Aristotle’s well-educated person an ancestor of someone who had learned to live without such bogus comforts – one who is evidence-sensitive, reality-focused and aware that the Universe itself is a vast experiment of which we are lucky to be a conscious and thinking part.