Key Concept
Principle of Specialization – The idea that work is more efficient and more effective if each worker specializes in exactly one task.
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Imagine you are standing at an empty intersection, waiting to cross the street. No one else is standing nearby, and there are no cars in sight. But there is a bright red ‘Do Not Cross’ sign illuminated. Do you wait for the signal to change to ‘Walk’?
This isn’t just a question about pedestrian safety. There is a deeper challenge: Do you follow the rules if you can get away with breaking them? Would everyone break the rules if they could? Why do we ultimately do what society tells us is the right thing to do?
Plato’s Republic tries to answer this question: as he puts it, ‘Why should we be just rather than unjust?’ In an extended argument over several books of the Republic, Plato explores human psychology, art and its role in education, and the best form of government, among other topics. Book 2 of the Republic provides the framing and motivation for answering this question about justice, and introduces several of the important concepts he will rely on throughout the text.
Plato (425-348 BCE) was an ancient Greek philosopher from Athens, and perhaps the most influential figure in the Western philosophical tradition. He founded the Academy, one of the first schools for philosophy (which at the time included rhetoric and science). Plato was a student of Socrates, and he wrote about many of his philosophical predecessors; he also had a profound influence on his student, Aristotle. Plato wrote nearly 30 dialogues on a variety of topics, which created the foundation for the discipline of philosophy as we know it. His work on ethics and metaphysics is especially important. In particular his Theory of Forms. As the early 20th century philosopher A.N. Whitehead famously opined, “The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato.”
The Republic is perhaps Plato’s most famous and influential work. The main focus of the Republic is the question ‘What is justice?’, centering it on ethics and political philosophy. But the Republic also expresses many of Plato’s ideas about aesthetics, metaphysics (including his Theory of Forms), and psychology, among other topics. The entire ten-book text can be found here.
Book 2 of Plato’s Republic is a transitional chapter, which continues the debate about justice from Book 1 and introduces important ideas that are deployed later in the text. In Book 2, we see Socrates take up the challenge of explaining why it is good to be just rather than unjust, but we have to wait until Book 4 to see a first full answer to that question. Book 2 should therefore be read as part of the Republic’s extended argument, rather than as a self-contained chapter.
Intrinsic Value – Value a thing has independently or inherently. Intrinsically valuable things are worth pursuing for their own sake. For example, you just have fun because it’s fun: you don’t have fun in order to get something else. Most ancient philosophers thought happiness was intrinsically valuable.
Extrinsic Value – Value a thing has that is dependent on something else. Extrinsically valuable things are worth pursuing because they get you something else that is valuable. Money, for instance, is only useful because it can be exchanged for other things.
Principle of Specialization – The idea that work is more efficient and more effective if each worker specializes in exactly one task. For example, a factory assembly line or kitchen staff will have each employee do only one small part of the larger process.
Book 1 of the Republic ends with Socrates winning an argument with Thrasymachus, concluding that just people are happy and unjust people unhappy. Yet Book 2 shows us that Plato is not done yet. Two other characters, Glaucon and his brother Adeimantus (Plato’s brothers in real life), immediately challenge Socrates to keep going.
So he said to me: Socrates, do you wish really to persuade us, or only to seem to have persuaded us, that to be just is always better than to be unjust?
I should wish really to persuade you, I replied, if I could.
Then you certainly have not succeeded. Let me ask you now:—How would you arrange goods—are there not some which we welcome for their own sakes, and independently of their consequences, as, for example, harmless pleasures and enjoyments, which delight us at the time, although nothing follows from them?
I agree in thinking that there is such a class, I replied.
Is there not also a second class of goods, such as knowledge, sight, health, which are desirable not only in themselves, but also for their results?
Certainly, I said.
And would you not recognize a third class, such as gymnastic, and the care of the sick, and the physician’s art; also the various ways of money-making—these do us good but we regard them as disagreeable; and no one would choose them for their own sakes, but only for the sake of some reward or result which flows from them?
There is, I said, this third class also. But why do you ask?
Because I want to know in which of the three classes you would place justice?
In the highest class, I replied,—among those goods which he who would be happy desires both for their own sake and for the sake of their results.
Then the many are of another mind; they think that justice is to be reckoned in the troublesome class, among goods which are to be pursued for the sake of rewards and of reputation, but in themselves are disagreeable and rather to be avoided.
Here, Glaucon introduces three categories of valuable things: some have intrinsic value, some have extrinsic value, and some have both. The challenge is to show that justice belongs to the first or third category, rather than the second. The worry is that, if justice only has extrinsic value, then it could be abandoned if we can get the same valuable things in other ways, or if there are other things that are more valuable. In other words, people may only act justly because of the rewards and punishments involved, not because of justice itself. The challenge is: can Socrates justify justice?
The distinction between intrinsic value and extrinsic value depends on where the value is located. If something is intrinsically valuable, it has its value by itself, on its own. If something is extrinsically valuable, then its value ultimately depends on something else. For example, if you have a job, you typically do that job in order to get paid, because you need that money for other things (like food or rent). If your job stopped paying you for work, you would probably stop doing the work. Likewise, if you won the lottery and no longer needed extra money, you would probably stop doing the work. This shows that your job is only extrinsically valuable: it’s only good to you to the extent it gets you something else. Compare this with a hobby you enjoy: you do it for fun, with no ulterior motive or extra incentives (it might even be costly in time or resources). Hobbies are intrinsically valuable because it is the hobby itself you enjoy, not the consequences. Note that these are not exclusive categories: the same activity may have both kinds of value. For example, a college class can be both extrinsically valuable (it gets you a degree you need for a better job), but also intrinsically valuable (it is interesting and good for you to learn).
Adeimantus now ups the ante by adding an additional challenge to Socrates. He and Glaucon worry that justice might actually make your life worse than injustice, because unjust people can get rich and powerful by breaking the rules and exploiting people, while the just do not take the same advantages. To make this worry concrete he introduces the famous story of the Ring of Gyges.
Now that those who practise justice do so involuntarily and because they have not the power to be unjust will best appear if we imagine something of this kind: having given both to the just and the unjust power to do what they will, let us watch and see whither desire will lead them; then we shall discover in the very act the just and unjust man to be proceeding along the same road, following their interest, which all natures deem to be their good, and are only diverted into the path of justice by the force of law. The liberty which we are supposing may be most completely given to them in the form of such a power as is said to have been possessed by Gyges, the ancestor of Croesus the Lydian. According to the tradition, Gyges was a shepherd in the service of the king of Lydia; there was a great storm, and an earthquake made an opening in the earth at the place where he was feeding his flock. Amazed at the sight, he descended into the opening, where, among other marvels, he beheld a hollow brazen horse, having doors, at which he stooping and looking in saw a dead body of stature, as appeared to him, more than human, and having nothing on but a gold ring; this he took from the finger of the dead and reascended. Now the shepherds met together, according to custom, that they might send their monthly report about the flocks to the king; into their assembly he came having the ring on his finger, and as he was sitting among them he chanced to turn the collet of the ring inside his hand, when instantly he became invisible to the rest of the company and they began to speak of him as if he were no longer present. He was astonished at this, and again touching the ring he turned the collet outwards and reappeared; he made several trials of the ring, and always with the same result—when he turned the collet inwards he became invisible, when outwards he reappeared. Whereupon he contrived to be chosen one of the messengers who were sent to the court; whereas soon as he arrived he seduced the queen, and with her help conspired against the king and slew him, and took the kingdom.
Suppose now that there were two such magic rings, and the just put on one of them and the unjust the other; no man can be imagined to be of such an iron nature that he would stand fast in justice. No man would keep his hands off what was not his own when he could safely take what he liked out of the market, or go into houses and lie with any one at his pleasure, or kill or release from prison whom he would, and in all respects be like a God among men. Then the actions of the just would be as the actions of the unjust; they would both come at last to the same point. And this we may truly affirm to be a great proof that a man is just, not willingly or because he thinks that justice is any good to him individually, but of necessity, for wherever any one thinks that he can safely be unjust, there he is unjust. For all men believe in their hearts that injustice is far more profitable to the individual than justice, and he who argues as I have been supposing, will say that they are right. If you could imagine any one obtaining this power of becoming invisible, and never doing any wrong or touching what was another’s, he would be thought by the lookers-on to be a most wretched idiot, although they would praise him to one another’s faces, and keep up appearances with one another from a fear that they too might suffer injustice.
Adeimantus now ups the ante by adding an additional challenge to Socrates. He and Glaucon worry that justice might actually make your life worse than injustice, because unjust people can get rich and powerful by breaking the rules and exploiting people, while the just do not take the same advantages. To make this worry concrete he introduces the famous story of the Ring of Gyges.
An invisibility ring might not seem very powerful in the modern world. But what if you had a way to digitally access billion-dollar bank accounts, give yourself millions of social media followers, and give yourself access to the most exclusive and well-connected organizations? Would you commit fraud in order to become rich and powerful? What if you could guarantee you wouldn’t get caught?
In order to meet this challenge from Glaucon and Adeimantus, Socrates proposes that they need to determine what justice is first, before they can determine whether and how justice is advantageous.
Seeing then, I said, that we are no great wits, I think that we had better adopt a method which I may illustrate thus; suppose that a short-sighted person had been asked by some one to read small letters from a distance; and it occurred to some one else that they might be found in another place which was larger and in which the letters were larger—if they were the same and he could read the larger letters first, and then proceed to the lesser—this would have been thought a rare piece of good fortune.
Very true, said Adeimantus; but how does the illustration apply to our enquiry?
I will tell you, I replied; justice, which is the subject of our enquiry, is, as you know, sometimes spoken of as the virtue of an individual, and sometimes as the virtue of a State.
True, he replied.
And is not a State larger than an individual?
It is.
Then in the larger the quantity of justice is likely to be larger and more easily discernible. I propose therefore that we enquire into the nature of justice and injustice, first as they appear in the State, and secondly in the individual, proceeding from the greater to the lesser and comparing them.
That, he said, is an excellent proposal.
And if we imagine the State in process of creation, we shall see the justice and injustice of the State in process of creation also.
I dare say.
When the State is completed there may be a hope that the object of our search will be more easily discovered.
The project of understanding justice leads Socrates to begin investigating the best form of government for a city, a project which will extend through most of the rest of the Republic.
It may sound strange to say that we can figure out what justice is for individuals by looking at cities first, because cities are bigger. But Socrates seems to be assuming an argument that might be more persuasive.
Premise 1: Justice is the same property wherever it occurs.
Premise 2: Cities and souls can both be just.
Premise 3: Justice is the same property in both cities and souls.
Premise 4: If justice is the same property in both cities and souls, then identifying what it is in one place will tell us what it is in the other.
Conclusion: Identifying what justice is in the city will tell us what it is in the soul.
The logic of this argument is valid, but you might have questions about any of premises 1, 2, or 4. Premises 1 and 2 in particular are worth considering: does it make sense to have the same standards for evaluating governments and for individual behavior?
To see what justice is in a city, Socrates begins by investigating why cities exist in the first place.
A State, I said, arises, as I conceive, out of the needs of mankind; no one is self-sufficing, but all of us have many wants. Can any other origin of a State be imagined?
There can be no other.
Then, as we have many wants, and many persons are needed to supply them, one takes a helper for one purpose and another for another; and when these partners and helpers are gathered together in one habitation the body of inhabitants is termed a State.
Socrates then explores how this city might develop, as they consider all the basic needs the inhabitants of the city might have (things like food, shelter, clothing, and tools). But rather than having each person aim to be self-sufficient and provide their own needs, Socrates and Adeimantus conclude it would be better if each person has only one occupation:
I am myself reminded that we are not all alike; there are diversities of natures among us which are adapted to different occupations.
Very true.
And will you have a work better done when the workman has many occupations, or when he has only one?
When he has only one.
Further, there can be no doubt that a work is spoilt when not done at the right time?
No doubt.
For business is not disposed to wait until the doer of the business is at leisure; but the doer must follow up what he is doing, and make the business his first object.
He must.
And if so, we must infer that all things are produced more plentifully and easily and of a better quality when one man does one thing which is natural to him and does it at the right time, and leaves other things.
Scholars call the idea that each person should have exactly one job the Principle of Specialization. The idea has two components: first, that each person only specializes in one job rather than many, and second, that each person has one job to do based on their abilities. This means that no one is without a job: a role can be found for everyone in the city, regardless of intelligence, strength, or skill. When everyone focuses on the job that they are best suited to doing, then the economy can operate at its most efficient.
Socrates continues by listing all the occupations a city needs to survive, including jobs like farmer, shepherd, carpenter, blacksmith, weaver, shoemaker, traders, sailors, merchants, and retailers. Once all the city’s basic needs are met, the result is a simple agrarian lifestyle which Socrates describes in idyllic terms.
Let us then consider, first of all, what will be their way of life, now that we have thus established them. Will they not produce corn, and wine, and clothes, and shoes, and build houses for themselves? And when they are housed, they will work, in summer, commonly, stripped and barefoot, but in winter substantially clothed and shod. They will feed on barley-meal and flour of wheat, baking and kneading them, making noble cakes and loaves; these they will serve up on a mat of reeds or on clean leaves, themselves reclining the while upon beds strewn with yew or myrtle. And they and their children will feast, drinking of the wine which they have made, wearing garlands on their heads, and hymning the praises of the gods, in happy converse with one another. And they will take care that their families do not exceed their means; having an eye to poverty or war.
But, said Glaucon, interposing, you have not given them a relish to their meal.
True, I replied, I had forgotten; of course they must have a relish—salt, and olives, and cheese, and they will boil roots and herbs such as country people prepare; for a dessert we shall give them figs, and peas, and beans; and they will roast myrtle-berries and acorns at the fire, drinking in moderation. And with such a diet they may be expected to live in peace and health to a good old age, and bequeath a similar life to their children after them.
Glaucon, however, is less pleased with the city that Socrates has described.
Yes, Socrates, he said, and if you were providing for a city of pigs, how else would you feed the beasts?
But what would you have, Glaucon? I replied.
Why, he said, you should give them the ordinary conveniences of life. People who are to be comfortable are accustomed to lie on sofas, and dine off tables, and they should have sauces and sweets in the modern style.
Yes, I said, now I understand: the question which you would have me consider is, not only how a State, but how a luxurious State is created; and possibly there is no harm in this, for in such a State we shall be more likely to see how justice and injustice originate. In my opinion the true and healthy constitution of the State is the one which I have described. But if you wish also to see a State at fever-heat, I have no objection. For I suspect that many will not be satisfied with the simpler way of life. They will be for adding sofas, and tables, and other furniture; also dainties, and perfumes, and incense, and courtesans, and cakes, all these not of one sort only, but in every variety; we must go beyond the necessaries of which I was at first speaking, such as houses, and clothes, and shoes: the arts of the painter and the embroiderer will have to be set in motion, and gold and ivory and all sorts of materials must be procured.
This more complicated city introduces a whole range of additional occupations for its citizens, including physicians, entertainers, and servants. This contrast presents us with a choice. The first city is a simple, agrarian society with fewer luxuries but also fewer problems. The second city is a more complex, urban society with more variety, but also more problems. Though Socrates follows Glaucon’s insistence to focus on the second city, he seems to prefer the first city himself.
Because the city is now much larger and richer, it has a need to defend itself from outside threats that it did not face before. This means that the city will need soldiers alongside its other citizens. But because of the Principle of Specialization, Plato does not think that all the citizens of the city should join the army. Instead, he thinks the city needs to have a separate group of professional soldiers.
And our State must once more enlarge; and this time the enlargement will be nothing short of a whole army, which will have to go out and fight with the invaders for all that we have, as well as for the things and persons whom we were describing above.
Why? he said; are they not capable of defending themselves?
No, I said; not if we were right in the principle which was acknowledged by all of us when we were framing the State: the principle, as you will remember, was that one man cannot practise many arts with success.
Socrates is worried, however, about the qualities it takes to be a good soldier: they need to be strong and fierce to their enemies, but friendly and protective to their co-citizens. These seem to be opposite properties, and it isn’t clear at first how one person could have both dispositions. Socrates finds an answer to this puzzle in the example of a household guard dog, who is trained to be friendly to members of the household but hostile to strangers.
And surely this instinct of the dog is very charming;—your dog is a true philosopher.
Why?
Why, because he distinguishes the face of a friend and of an enemy only by the criterion of knowing and not knowing. And must not an animal be a lover of learning who determines what he likes and dislikes by the test of knowledge and ignorance?
Most assuredly.
And is not the love of learning the love of wisdom, which is philosophy?
They are the same, he replied.
And may we not say confidently of man also, that he who is likely to be gentle to his friends and acquaintances, must by nature be a lover of wisdom and knowledge?
That we may safely affirm.
Then he who is to be a really good and noble guardian of the State will require to unite in himself philosophy and spirit and swiftness and strength?
Socrates says little about the work of the guardian class at this point, but it is clear that there are strict standards for who qualifies to be among them.
As much as Plato emphasizes the Principle of Specialization, it may be surprising that he describes the guardians as being both soldiers and philosophers. Certainly we would consider soldier and philosopher to be different jobs today.
Plato is aware of this possible objection. On the one hand, we can make a distinction between occupation and temperament: technically what Plato had described is a philosophical character or personality, which is not the same thing as a philosophical occupation. And on the other hand, in Book 3, Plato does eventually make a third occupational class, the philosopher-kings, which are distinct from the guardian-soldiers.
Now that we have identified what kind of person will be a guardian of the city, Socrates turns to discussing their education. While both physical and intellectual education are mentioned, Socrates seems most concerned with moral education, and especially the way young children are influenced through the stories they hear.
You know also that the beginning is the most important part of any work, especially in the case of a young and tender thing; for that is the time at which the character is being formed and the desired impression is more readily taken.
Quite true.
And shall we just carelessly allow children to hear any casual tales which may be devised by casual persons, and to receive into their minds ideas for the most part the very opposite of those which we should wish them to have when they are grown up?
We cannot.
Then the first thing will be to establish a censorship of the writers of fiction, and let the censors receive any tale of fiction which is good, and reject the bad; and we will desire mothers and nurses to tell their children the authorised ones only. Let them fashion the mind with such tales, even more fondly than they mould the body with their hands; but most of those which are now in use must be discarded.
The rest of Book 2 argues for an educational regime where the gods are only depicted in a positive light. Here, Plato rejects the kinds of stories we see in Greek mythology, such as Homer or Hesiod, where the gods engage in immoral behavior of all sorts. The only poets who are allowed to practice in the city will represent God as a perfect and unchanging source of good. Plato even hints at a kind of monotheism here: his examples of rejected stories involve the Greek pantheon, whereas his approved messages refer to a single, everlasting God.
Modern American culture has seen a number of popular moral panics based on worries about influences on children. From jazz and dance clubs in the 1930’s, to heavy metal and roleplaying games in the 1980’s, to TikTok and school library books today, there has been a cycle of efforts to censor or restrict access to educational and entertainment resources for young people. How much influence do you think education has on children’s moral development? Is it appropriate for the government to use education to develop citizens who follow the government’s ethical outlook?
Republic Book 2 introduces the question which the entire work is devoted to answering: what makes justice better than injustice? In addition to introducing one of the most famous thought experiments in all philosophy (the Ring of Gyges), Republic Book 2 also begins sketching Plato’s depiction of an ideal political arrangement, and his preferred educational regime. The Principle of Specialization introduced here will shape much of Plato’s discussion of justice in the rest of the Republic.
For a big-picture overview of Plato’s justification of justice in the Republic, and a comparison with answers from other influential philosophers, check out this short video:
To see a conclusion to the argument Plato begins in Book 2, you’ll have to continue reading through at least Books 3 and 4, and perhaps all the way to Book 10. You can find a summary and analysis of the entire work at the Internet Encyclopedia of Philosophy or the Stanford Encyclopedia of Philosophy. If you are interested in other works of Plato, you can check out the Apology; if you want to see other approaches to ancient Greek ethics, Aristotle’s Nicomachean Ethics is a great place to start.
This work has been adapted from Republic, a title from the eCampusOntario Public Domain Core Collection. This work is in the Public Domain. All images were created using Midjourney.
Green, Jerry. 2025. “Why Be Good? The City and The Soul: Plato’s Republic, Book 2.” The Philosophy Teaching Library. Edited by Robert Weston Siscoe, <https://philolibrary.crc.nd.edu/article/the-city-and-the-soul>
Principle of Specialization – The idea that work is more efficient and more effective if each worker specializes in exactly one task.
Extrinsic Value – Value a thing has that is dependent on something else. Extrinsically valuable things are worth pursuing because they get you something else that is valuable. Money, for instance, is only useful because it can be exchanged for other things.
Intrinsic Value – Value a thing has independently or inherently. Intrinsically valuable things are worth pursuing for their own sake.
Adeimantus and Glaucon were Plato’s older brothers (along with an older sister, Potone). They were both honored for military valor at a battle with Megara. We know little about their lives otherwise. Potone had a son, Speusippus, who inherited leadership of the Academy upon Plato’s death.
Thrasymachus was a real person, who lived about 459-400 BCE moved to Athens from Chalcedon to become a sophist (a professional teacher and public speaker). Only a few fragments of his work survives
Prudence – Prudence is virtue wherein a person is able to choose, in any given situation, the course of action that will lead to greater happiness. For example, a prudential person knows when it is appropriate to continue a difficult conversation and when it is best to wait for a more appropriate time.
Pleasure – Epicurus would have us think about pleasure as coming in two forms: moving and static. Moving pleasures are the type that we experience in the process of satisfying a desire (this coffee tastes amazing!). Static pleasure is the feeling of being satisfied — no longer experiencing need or want (I am feeling so peaceful sitting in the park). Epicurus thinks these static pleasures are the best sort.
Epicurus believed that reality is composed of matter. This sets him apart from other philosophers of the time who, often influenced by Plato, believed that reality is composed of both the material and immaterial (like the soul, or the Platonic forms).
Happiness – Epicurus uses the Greek word “eudaimonia,” which is typically translated into English as “happiness.” Whereas today happiness is most often used to describe a momentary feeling (this new notebook makes me happy!) Epicurus means something more like a consistent state of well-being and contentment.
Unconditioned: an ultimate explanation of reality. For example, if I explain why it is raining today by appealing to some atmospheric conditions, I can always ask for the cause of those conditions, and so on. Only a cause that is not caused by anything else (something unconditioned) would give us an ultimate explanation.
Transcendental Idealism: Kant’s mature philosophical position. It holds that appearances are not things in themselves, but representations of our mind. It is opposed to transcendental realism, which identifies appearances with things in themselves.
Appearances (vs. things in themselves): things as they are experienced by us (also known as phenomena). They should be distinguished from things as they are independently of our experience (things in themselves or noumena).
Metaphysics: the study of what there is. Traditionally, metaphysics is divided into general metaphysics and special metaphysics. The former investigates the general features of reality and asks questions such as ‘What is possible?’. The latter studies particular kinds of being and asks questions such as ‘Does God exist?’ or ‘Is the soul immortal?’.
Reason: the faculty that knows a priori. Kant uses this term in a general sense (the knowing faculty as such) and in a specific sense (the faculty that demands ultimate explanations).
A priori: term denoting propositions that can be known independently from experience. For example, propositions such as ‘All bachelors are unmarried’ or ‘The whole is greater than its parts’ can be known without recourse to any experience.
Make sure not to think that ‘unjustified’ means ‘false.’ Even if they are true, the point is just that this would not be something that had been shown.
‘Absolute’ might be a confusing word, here. Socrates means that the geometers are not reasoning about their drawing of the square, for example, but of the square itself. They do not conclude that, for the square they drew, the area is equal to the square of a side – they conclude that this is true for squares as an intelligible object, or, as Plato would say, the Form of the square.
By ‘science’, Plato means to be talking about all rational disciplines, including mathematics.
The form of the beautiful has to be perfectly beautiful because all instances of beautiful things are explained by it, so it has to be responsible for the highest possible degrees of beauty possessed by anything. Moreover, it has no trace of ugliness in it.
The form of the beautiful has to be immaterial because all the many beautiful things do not share any material – that is, they are all made of different stuff.
Form (εἶδος / ἰδέα) – Intelligible, immaterial, perfect entities that explain the unity among the many things which share the feature named by the entity (e.g., Beauty, Squareness, Oddness). For example, think of a square. There might be many different squares, but they all share features like having four sides of equal length. So, the Form of Squareness would include all of those features that make something a square.
Guardian – This is the name Plato gives to the ruling class in his ideal city. Think of them as philosopher kings – they have complete control over the organization of the state. The Republic is partially about why Plato thinks they would be needed for an ideal system of government and what they would need to learn to do the job well.
Plato has previously argued that we are made up of different parts. The first part is the appetitive which is responsible for our desires for food, sex, and other bodily needs. Then there is the spirited part, which longs for fame and honor. Finally, he identifies the rational part, which discerns what is good and bad for us through reason. The parts can all come into conflict with one another, and managing their relations is what Plato thinks justice is all about.
Soul (ψῡχή) – What Greeks meant by this word is controversial. For now, think of it as the thing that makes you different from a rock or other objects, the thinking and experiencing part of you as well as the part of you that acts and makes decision. You might use the word ‘mind’ or ‘self’ to talk about this.
Virtue – Virtues are the character traits that make a person good. For example, most people consider courage and generosity to be virtues. English-speakers usually reserve the word ‘virtue’ for human beings, but in ancient Greek the word can be more comfortably applied to other beings as well.
Was it his burly physique, his wide breadth of wisdom, or his remarkable forehead which earned him this nickname?
Aporia – A Greek term for “being at a loss” or “clueless.” Socrates often questions people until they have no idea how to define something that they thought they understood.
You might be confused by the word ‘attention’ below. In Greek the word is therapeia, from which we get the English word ‘therapy.’ It primarily means the same as ‘service’ as in ‘to serve,’ but shades into ‘worship,’ ‘take care of,’ and ‘attend to.’
Meletus – A poet and citizen of Athens and one of Socrates’ accusers. Amongst other things, Meletus accused Socrates of impiety and corrupting the youth.
Divine Voluntarism – The idea that God is free to determine even the most basic truths. If divine voluntarism is true, then God could have made it so that 2+2=5 or so that cruelty and blasphemy are holy and good.
Euthyphro Dilemma – The question, “Is a thing holy because the gods love it, or do the gods love it because it is holy?” The general idea of a forced choice (or “dilemma”) about the true order of explanation occurs often in philosophy and gets referred to by this term.
Essence – What a thing fundamentally is. A square might be red or blue without changing the fact that it’s a square, but a square must have four sides, so having four sides is part of a square’s essence.
Definition – The perfect description of a thing. A definition should pick out all and only examples of a thing. For example, ‘bachelor’ might be defined as ‘unmarried man,’ because all unmarried men are bachelors, and only unmarried men are bachelors.
In Disney’s retelling of the Hunchback of Notre Dame, the clergyman Claude Frollo orders the death of many Roma on religious grounds. It is clear, however, that he is really motivated by spite and his unrequited lust for the Romani woman Esmerelda.
Spanish conquistadors were shocked by the scope of ritual human sacrifice among the Aztecs, as hundreds or even thousands of people were sacrificed each year. The Aztecs thought that the sacrifices could repay the sacrifices the gods had made in creating the sun and earth.
Zeus – The god of sky and thunder in ancient Greek mythology, Zeus was depicted as chief among the gods and called the father of the gods and men.
Forms – The perfect, divine, and intelligible entities that exist independently of the physical world. They are comprehensible only through reason, not through our senses, and their existence explains the properties of objects in the physical world.
Recollection – The soul existed prior to birth; during this time it learned everything, and hence all learning is only recalling what we already know.
Immortality of the Soul – Unlike the body, the soul is not subject to physical death, because it is immortal and indestructible.
Philosophy – The practice of preparing the soul for death by training it to think and exist independently of the body
Death – Plato understands this as the soul’s separation from the body
Human Identity Across Time – Locke’s notion that any human stays the same across time if, and only if, it maintains the same (distinctively human) organizing structure of parts.
Substance Identity Across Time – Something is the same substance across a segment of time if, and only if, it continuously exists across the relevant segment of time without gaining or losing any of its parts.
Immaterial Soul – A personal thinking substance without any physical constitution.
Personal Identity Across Time – Whatever makes someone the numerically same person (i.e., that very person) at different times; according to Locke, it is a relation of first-person consciousness via memory.
Person – Locke’s forensic definition of person (pertaining to courts of law regarding the justice of praise, blame, reward, or punishment): a thinking, intelligent being, that has reason and reflection, and can consider itself as itself, the same thinking thing in different times and places.
The Prophet Muhammad is a central figure in Islam. He is viewed as the last of a long line of prophets, which includes Moses and Jesus. He is responsible for writing the Quran, which was dedicated to him by the angel Gabriel. His life and sayings are recounted in the Hadith; he is viewed as an exemplary role model of Islamic life and faith.
Exhortation — The method of understanding and interpreting Truth available to the common people. The majority of people take scripture literally and understand truth and right action based upon this understanding. They are persuaded by the vivid imagery of the Quran and the rhetorical exhortations of religious leaders. Averroes takes this to be lowest form of understanding
Dogmatic Discourse — The method of understanding displayed by those who, through natural ability and habit, are able to have a deeper understanding of the Quran, and of the truths it illuminates. These people know that not all of the scriptures are to be taken literally, and that greater underlying Truths are revealed by interpreting some elements allegorically. Still, they err on the side of dogmatism and literal interpretation whenever uncertainty arises. Averroes associates this way of thinking with Muslim theologians and views this to be the middle level of understanding.
Philosophical Inference – The type of understanding associated with philosophical demonstration or argument. This is the highest level of understanding, accomplished by a select few, who have a natural capacity for philosophy and proper philosophical training.
Law — The Quran (the central religious text of Islam) and, to a lesser extent, the Hadith (reports of what the prophet Muhammad said and did). Averroes is concerned with explaining how philosophy relates to what Muslims take to be the unerring Truth regarding God and the nature of existence, as they are expressed in Scripture.
Occasionalism — a theory claiming that God is the only true cause of changes in the world. For example, when you high-five me, you’re not really the cause of the stinging sensation I experience. God is the cause. Your high five is just the occasion on which God causes it.
Interactionism — a theory claiming that things in the world can truly cause changes in each other. For example, when you high-five me, you truly cause me to experience a stinging sensation in my hand.
Substance Dualism — a theory claiming that the mind (or soul) and body are two distinct and very different things.
Body — what it sounds like! The body is the physical part or aspect of a thing and has characteristics like shape, size, etc.
Soul — that part or aspect of a thing involving mental aspects of their existence, e.g., thoughts, feelings, decisions, etc. The “soul”, in this sense, is more or less just the mind.
Causal Interaction — When one thing acts (i.e., itself does something) and in so acting makes another thing change. For example, when you high-five me, you cause me to experience a stinging sensation in my hand.
God as God – The phrase “God as God” is basically a synonym for “God the subject.” In other words, it refers to God precisely in God’s status as an incomprehensible divine Other.
Incarnation – The Christian doctrine of the incarnation is the notion that the word of God became fully human in the person of Jesus of Nazareth. It is closely associated with the doctrine of the trinity, which asserts that God the Father, God the Son (Jesus as the word made flesh), and God the Holy Spirit are one God.
Religious Fanaticism – In Feuerbach’s use of the term, a religious fanatic is someone who is unwaveringly faithful to God as an utterly mysterious superhuman being. They subordinate other things—especially the love of other humans—to submission before this divine other.
God the Subject – When Feuerbach refers to God as a subject, he is referring to the commonplace religious belief that God is a being who has various attributes, like a loving nature.
Faith Separates Man From God – Faith separates God from man in this sense: it treats God as a mysterious other, a being radically distinct from us.
Faith – Belief in and fidelity to a transcendent divine subject like God.
Orthodoxy – Orthodoxy refers to “right belief,” and it is concern with identifying heresies and ensuring that people believe and practice correctly.
Indirect Form of Self-Knowledge – Feuerbach’s view is that religious belief is a naive way of relating to our human nature and its perfections. It is naive or childlike because it treats these as external realities that belong to God. He believes a mature and contemplative person realizes these don’t belong to God, but rather to our species, abstractly conceived.
Above the Individual Man – The human perfections are “above the individual” insofar as no particular individual ever perfectly realizes them. They are abstractions.
Divine Trinity – Feuerbach is having fun here. He is using the theological phrasing of the Trinity to talk about human perfections. In calling reason, love, and freedom of the will “divine,” he means they are absolutely good; they are activities whose goodness is intrinsic to their practice or exercise. This isn’t a novel philosophical view. For example, Immanuel Kant argued that autonomy or a good will is the only thing which is unconditionally good.
Perfections – The end to which a faculty or power is ordered. For example, omniscience would be the perfection of the intellect. Traditionally, God is said to possess all perfections.
Love – When Feuerbach writes about love, he is referring to unconditional concern for others and the desire for fellowship with them. He is here asserting that love, understood in this sense, is the perfect activity of the affective faculty. In other words, our feelings and passions are fully actualized and engaged in an intrinsically valuable activity when we genuinely love others.
Infinite – The infinite is whatever can be understood as unbounded or unlimited. Human nature in the abstract is unbounded and unlimited. It is only bounded or limited in its concrete form as it is realized by particular material individuals.
Higher Consciousness – The sort of consciousness that mature human beings possess, but which other animals do not. It is “higher” than animal consciousness because it involves thinking abstractly about the form or essence of things.
Science – Feuerbach uses the term science in its classical sense, meaning systematically organized knowledge. Any body of knowledge founded on an understanding of first principles and the essences of things is a science in this sense.
Popular Sovereignty – The view that a government’s authority to rule comes from the people, making a ruler subject to the will of their citizens.
The Divine Right of Kings – The theory that kings are chosen by God and thus that political revolt is a rebellion against the will of God.
Synthesis – The prefix ‘syn-’ means “together,” so a synthesis “brings together” or combines elements of both a thesis and its antithesis.
Antithesis– An antithesis is the contradiction of a thesis. For example, internationalism could be understood as the antithesis of nationalism.
Thesis – In Hegelian terms, a thesis can be understood as a position or theory. Examples include any of the “-isms” that we discuss in science, history, and philosophy, such as Darwinism, capitalism, nationalism, etc.
Progressor’s Temptation – a unique temptation for those making progress in which pride impedes their further progress and leads to backsliding.
Progressors – those who are not yet expert Stoic practitioners, but who are also aware of the fact that they must change their lives in that direction. They are working on making progress.
Intellectualism – the philosophical view that our motivations and emotions are all judgments. The reason why you do something, your motivation, is because you believe it’s the right thing to do. The reason why you feel good or bad about something, an emotion, is because you believe that something good or bad happened to you.
Duties – acts of service, obedience, and respect that we owe to each other. The duties we owe to each other depend on what kind of relationship we have.
Askeses – exercises of Stoic thought and practice that make the lessons and habits of Stoic philosophy second-nature for Stoic practitioners.
Externals – things that are not under our control but that are all-too-easily confused with things that should be important to us, like wealth, status, and pleasure. Too many people believe externals like these are necessary for the good life, and the Stoic path is to focus not on these things but rather what is up to us.
The Fundamental Division – the division between things that are under our direct control and those that are not. The important lesson is to care only about the things we can control.
The Greatest Happiness Principle – A principle which says that actions are right insofar as they promote happiness and wrong insofar as they promote unhappiness
Higher and Lower Pleasures – Types of pleasures that differ in terms of their quality. Things like food and drugs create lower pleasures. Things like intellectual pursuits and doing the right thing create higher forms of pleasure.
The Doctrine of Swine – An objection that utilitarianism entails that if people would be happy rolling in mud, that’s what would be morally best for them to do, so we should reject the theory.
Utilitarianism – A normative theory of which actions are right or wrong. Utilitarianism says the right action is that which maximises utility.
Jeremy Bentham – Considered by some as the father of utilitarianism, Bentham was a moral philosopher and one of John Stuart Mill’s teachers
Epicurus – an ancient Greek philosopher and one of the first to advocate that the ultimate good is experiencing pleasure and avoiding pain.
Utility – The thing that is ultimately valuable in itself. For Mill, this is happiness, which he then understands as pleasure and the absence of pain.
Contract Theory – a modern political theory identifying consent as the sole justification for government. Contract theory is associated with Thomas Hobbes (1588-1679), John Locke (1632-1704), Jean Jacques Rousseau (1712-1778), and more recently, John Rawls (1921-2002)
Prejudice – a foundational, strongly held, unreasoned (but not necessarily irrational) moral opinion or belief. We might believe, for example, that parents have special obligations towards their own children.
A Priori – a philosophical term of art meaning (in Latin) “prior to experience,” which refers to knowledge that is innate or arrived at purely through reasoning, like the truths of mathematics.
Rights – moral claims invoking immunity from (or entitlement to) some specific treatment (or good) from others. Commonly recognized rights include the right to free speech or the right to healthcare.
Reform – a change in the social order that originates from the existing character of society. An example would be market-based healthcare reform in a capitalist society.
Conservatism – a modern political ideology that aims to preserve and promote the existing (or traditional) institutions of society. These institutions typically include the rule of law, property, the family, and religion.
Contingent Being – A being that can fail to exist. Its existence is not guaranteed. This being might come to exist or it might not.
Necessary Being – A being that can’t fail to exist. Its non-existence is impossible. This also means that such a being has always existed.
Want to read more about why the infinite regress option doesn’t work in the Second Way? Check out Sean Floyd’s entry in the Internet Encyclopedia of Philosophy.
Efficient Cause – An efficient cause is something that directly makes another thing exist or move. An example of this is when I kick a ball down a hill. I am the efficient cause of the ball rolling down the hill because I make it move down the hill.
Infinite Regress: Begin with some fact. We begin to explain that fact by appealing to another fact, where these facts are related by either causality or dependence. To create the regress, you keep appealing to more and more facts about causality and dependence without end.
Actuality – An ability or action something is currently exercising. Imagine that I am sitting comfortably at my desk, and then I stand up to take a break from reading. In this case, I am now actually standing.
Potentiality – What something has the capacity to do, but isn’t currently doing. Imagine I am sitting comfortably at my desk. Even though I’m not currently standing, I have the capacity to be standing. So, even while I’m not standing, I have the potential to stand.
Theists and Non-Theists – A theist is someone who believes that God exists, while a non-theist does not. Non-theists include atheists, who believe that God does not exist, and agnostics, who are uncertain about whether God exists.
Glaucon – one of Plato’s brothers and one of Socrates’ main interlocutors in the Republic dialogue. In that dialogue, he challenges Socrates to provide a compelling justification for why one should be a just person beyond merely following conventions or avoiding punishment. This sets up Socrates’ defense of justice as intrinsically worthwhile. Throughout the Republic, Glaucon prods Socrates to fully explain his theories of the ideal society, philosopher-kings, and the Form of the Good.
Aristotle – a Greek philosopher (384-322 BC) who studied under Plato and went on to be one of the most influential philosophers to ever live. Simply called “The Philosopher” by Thomas Aquinas and others in the medieval period, Aristotle’s views would eventually be synthesized with Christian theology, laying the intellectual foundation for later scholarly developments in Western Europe.
Understanding – Socrates describes education as turning one’s “understanding” in the right direction. The word “understanding” here translates the ancient Greek term “to phronēsai,” which means “understanding,” “being conscious,” or “having insight.” People who are wicked focus their “understanding” on how best to accomplish their selfish and narrow desires. Those who are wise, in contrast, have learned to focus their “understanding” on what is truly good and beneficial.
The Form of the Good – Socrates characterizes the ultimate goal of education as coming to know “the Form of the Good.” The Form of the Good is his technical term for the meaning of goodness: what it is to be good. Socrates is clear that this “knowledge of the Good” is not simply theoretical knowledge, but also knowledge in the sense of “knowing how”: knowing how to achieve what’s good, to do what’s good, to accomplish what’s good. Mere “book knowledge” or simply being smart is not enough.
The Intelligible – Socrates uses “the intelligible” to name the aspects of the world that we can only grasp through thinking or insight. With my eyes I can see the tree outside my window, but what it means to be a tree is something I can only comprehend in thought. Likewise, I can see the people around me, but human nature, human dignity, and what it means to be human is something I can only grasp conceptually. “The intelligible” is the world insofar as it “makes sense” and can be comprehended.
The Visible – By “the visible,” Socrates means those aspects of the world we can perceive with our five senses and our imagination—those aspects of the world we can see, hear, taste, smell, touch, and imagine. For example, with my eyes I can see the sky, trees, people around me, and so on as visible things. “The visible” is the world insofar as it can be perceived and imagined.
Education – Socrates says that the allegorical story he tells represents the effect of education on human nature. “Education” here is a translation of the ancient Greek word “paideia,” which means “education” in the widest sense of the term. “Paideia” doesn’t mean “education” in the sense of going to school or getting good grades. Instead, it refers to the process of becoming a wise, intelligent, good, and well-rounded human being.
Allegory – An allegory is a symbolic narrative where characters, events, and/or settings represent abstract ideas or convey deeper meanings beyond the literal story. Socrates tells such a symbolic narrative in the passages below. The characters, events, and setting of his narrative symbolize the effect of what he calls “education.”
Self-knowledge – Knowledge of the contents of one’s own mind, such as one’s own beliefs and desires. Self-knowledge can be gained through introspection, that is, by reflecting on what one thinks and experiences. Some philosophers believe that self-knowledge has special properties that our knowledge of the external world lacks, such as being clearer, more reliable, or more valuable.
Dualism – The view that the mind is entirely distinct from the body. This view is usually contrasted with different kinds of monism, which hold that the mind is ultimately just a part of the body (materialism) or that the body is ultimately just a part of the mind (idealism). Dualists hold that the mind and the body are fundamentally different aspects of reality, and both categories are needed to properly describe the universe, especially the human person.
The Self – What the ‘I’ in ‘I am, I exist’ refers to; the part of you that really makes you you. Many philosophers have provided rich accounts of what the self ultimately is, including the soul, the mind, one special feature of the mind (such as consciousness), a mixture of all these elements, or perhaps a mere illusion.
The ‘Cogito’ – Descartes’ famous claim ‘I think, therefore I am’ is often referred to as the cogito. The name comes from the Latin rendering of this phrase, which is ‘cogito, ergo sum.’ Descartes held that one can always believe this proposition with certainty. We cannot doubt our own existence, so the cogito survives his exercise of intense doubt. The cogito appears several times in Descartes’ writings, and he often phrased it slightly differently each time. It appears in the Second Meditation as ‘I am, I exist.’
Certainty – When one believes something with certainty, one is maximally confident that it is true. A certainty is something that is beyond dispute or immune to doubt. Although this captures the basic idea, like many epistemological notions, clarifying precisely what the notion of certainty amounts to is an ongoing area of philosophical research.
Vice – A bad habit that we learn over time through instruction or instinct and that we develop through repetition. What makes the habit bad is that, once we have that habit, our tendency is to do the incorrect thing in certain types of situations. We may choose to do something entirely uncalled for in that situation, or we may act at the wrong time, in the wrong way, to the wrong degree, or with the wrong attitudes, or for the wrong reasons.
Relative Mean – The “Goldilocks amount” of some type of action or emotion. When you act in this way, according to Aristotle, you act exactly as is required under the current circumstances. This means that you do what is called for by the situation at hand, rather than doing something too extreme or not doing something extreme enough. You do something in the moderate amount (the mean amount) relative to the specific situation you are in when you need to act.
Excellence/Virtue – A good habit that we learn over time through instruction and repetition. What makes the habit good is that, once we have that habit, we have a strong tendency to do the right thing at the right time, in the right way, to the right degree, with the right attitudes, whenever we are confronted with a situation that we know calls us to exercise that habit.
Doxastic Voluntarism – the view that we have at least some control over what we believe.
Evidence – information that increases the probability that a claim is true.
Sufficient – enough of something for a particular purpose. Whether something is sufficient is context-dependent.
Solon – In the Histories of Herodotus, Solon visits Croesus, the king of Lydia. Even though Croesus shows Solon all of his wealth, Solon refuses to call him the happiest man who ever lived because he does not know how Croesus will die
Priam – According to Greek mythology, Priam was the final king of Troy during the Trojan War. Despite his wealth and political power, he was killed by Achilles’ son Neopotolemus during the Sack of Troy
Virtue – The consistent and reliable tendency to perform one’s function excellently. When a person has a certain virtue, like courage, they have spent time developing the habit, in this case reacting to danger well, using their human abilities. The virtues then make it possible for us to live a life of flourishing
Sardanapalus – An Assyrian king described by the historian Diodorus as living a life of extreme decadence. Sardanapalus indulged himself with food, alcohol, and many concubines, even going so far to say that physical gratification is the purpose of life. Chrysippus said that, on his tomb is inscribed the following: “Though knowing full well that thou art but mortal, indulge thy desire, find joy in thy feasts. Dead, thou shalt have no delight […] I have only what I have eaten, what wantonness I have committed, what joys I received through passion; but my many rich possessions are now utterly dissolved.”
Function – the characteristic activity of a given thing which makes it what it is. The function of a knife is cutting, while the function of a heart is to pump blood
Eudaimonia – Frequently translated as ‘happiness’, eudaimonia means the attainment of active human flourishing, and is the end Aristotle identifies as humanity’s highest final good
Final Good – A good that we pursue for its own sake. Common examples of final goods include happiness, knowledge, and friendship
Instrumental Good – A good that we pursue for the sake of some other good. A common example is money, as money allows us to purchase other kinds of goods
Anytus – an Athenian politician, war general, and one of the primary accusers behind Socrates’ prosecution. Anytus feared that Socrates would undermine the young Athenian democracy he had helped create and defend
Oracle of Delphi – the high priestess at the temple at Delphi, the oracle was one of the most sought after seers of the ancient world and was thought to relay messages from the god Apollo
Chaerephon – an ancient Greek from the city Sphettus, Chaerephon is remembered as a loyal friend of Socrates, also making an appearance in two other Platonic dialogues, the Charmides and the Gorgias
Meletus – A poet and citizen of Athens and one of Socrates’ accusers. Amongst other things, Meletus accused Socrates of corrupting the youth
Apollo – the ancient sacred site Delphi was dedicated to the god Apollo, an ancient Greek god and the god that Socrates refers to throughout the Apology
Virtue – a character trait, acquired through habitual practice, that enables one to act well. The virtues can also be thought of as excellences of human character, as they make it possible for us to live a life of flourishing. Examples of the virtues include courage, prudence, and justice
The Evil Demon Argument – Argues that we cannot hold any of our beliefs with certainty because we could be radically deceived by an evil demon. A classic argument given by Descartes for doubting the reliability of almost all of our beliefs
Philosophical Skepticism – The position that we do not know many things that we ordinarily take ourselves to know
A Posteriori Knowledge – Knowledge that can only be acquired through having particular, concrete experiences. Such knowledge can be gained simply through our everyday experiences, or through more complex means like controlled scientific experiments
A Priori Knowledge – Knowledge that can be gained without having any particular concrete experiences. Such knowledge is typically gained by rational insight or intuition
Cartesian Method of Doubt – A process employed by René Descartes of rejecting all beliefs that he had at least some reason to doubt in order to see if he had any beliefs that he could know with certainty
Revelation – Theological truths that have been made known by means of some religious text, testimony, authority, or experience, or the act or process in which such truths are made known.
Rationalism – The view that the only reliable means of coming to know truths about God is reason. As a result, what we might otherwise believe by means of faith ought to be disregarded or even rejected in favor of what we must believe by means of reason.
Fideism – The view that the only reliable means of coming to know truths about God is faith. As a result, what we might otherwise believe by means of reason ought to be disregarded or even rejected in favor of what we must believe by means of faith.
Faith – The act of accepting a proposition as true for which there is less than demonstrable evidence, which rises above mere opinion but falls short of logical or scientific demonstration. Faith can also refer to a particular religious tradition or the body of beliefs that are central to that religious tradition.
Virtue – a character trait, acquired through habitual practice, that enables one to act well. The virtues can also be thought of as excellences of human character, as they make it possible for us to live a life of flourishing. Examples of the virtues include courage, prudence, and justice
Socratic Ignorance – an awareness of one’s own ignorance, and the reason that Socrates was deemed wise by the Oracle of Delphi. A person who lacks Socratic Ignorance may believe they know many things they actually don’t, leading them to overestimate how well they understand the world
Apology – a formal defense of justification of an action or belief. A Christian apologist, for example, is someone who defends their faith and seeks to justify it through an appeal to reason.
