Suppose you are spending the summer working on an apple orchard. You have a great big barrel of freshly picked, sweet, and crunchy red apples. Unfortunately, the orchard’s trees are not perfect. Sometimes they produce a rotten apple or two, and you are worried that some of those have ended up in your barrel. Before you seal up the barrel to place it in refrigerated storage, you want to root out the bad ones. You know that if they are not discarded then the rot could spread through the whole barrel. So, you pour out all the apples onto a large table. You carefully examine them, picking each one up and inspecting its quality. Only the fresh apples go back in the barrel.
This story comes from René Descartes. It is one of the images he often used to describe his grand intellectual project. Your mind is like a barrel, and your beliefs are like apples. If you were to tip out the contents of your mind, and carefully examine each belief, some of them would turn out to be false. Perhaps that is because you have come to believe them due to innocent mistakes in your reasoning, or perhaps you have uncritically absorbed some of your beliefs from your culture or friends, or perhaps you have been misled by plausible, but ultimately flawed, evidence. Whatever the cause, it is important to set aside the false ones before the rot spreads to the whole lot.
Descartes begins the First Meditation of his Meditations on First Philosophy by resolutely setting out to determine whether there is a way that he could have only true beliefs, and so successfully guard against believing anything false. Truth and falsity are important notions. But in the Second Meditation, Descartes’ focus subtly shifts from these to a nearby notion: certainty.
Imagine that you are back at the table, inspecting your beliefs. As you try to judge whether each one is true or false, your judgment will come in different degrees of strength. Sometimes you will think that it is very likely that a belief is true. Sometimes you will think that it is possible, but fairly unlikely, that a belief is true. Sometimes you will think that it is roughly 50-50 whether a belief is true or false.
The central question of Descartes’ Second Meditation is: Can you be certain that any of your beliefs are true? Is there any belief such that, were you to pick it up off the table and inspect it, you would just know, without a shadow of a doubt, that it was true?
In this reading, we will engage with Descartes’ famous answer to this question—an answer that would have a colossal impact on the future course of Western philosophy.
René Descartes (1596-1650) was a French mathematician, scientist, and philosopher. He was born in the town of La Haye (now renamed ‘Descartes’) and spent most of his adult life in the region of Northern Europe that is now the Netherlands. By the end of his life, he had become one of Europe’s most famous intellectuals. In the final year of his life, he served as the tutor to Queen Christina of Sweden and drafted the founding statutes for the Royal Swedish Academy of Sciences.
Descartes lived through a time of significant social change, marked especially by the Scientific Revolution and the Thirty Years War (1618-1648). His writings cover a large range of topics, including optics and astronomy (in science), algebra and geometry (in mathematics), and metaphysics, epistemology, the philosophy of mind, and the philosophy of emotion (in philosophy). In many of these fields, his work made a seminal contribution, such as pioneering the Cartesian coordinate system (in mathematics) and establishing the terms for how philosophers ever since have thought about the nature of knowledge and the relationship between the mind and the body (in philosophy). The thread that connects much of Descartes’ work is his concern that traditional intellectual systems were increasingly coming into conflict with new scientific accounts of the world. His writings embrace a spirit of exploration and discovery by setting aside much of the ancient and medieval intellectual work that came before him and attempting to look afresh at some of the most fundamental questions in philosophy and science.
In his Meditations on First Philosophy, Descartes embarks on a kind of intellectual cleansing and reorientation. He explores a radical way that we might free ourselves from everything that distorts our thinking—such as preconceived opinions, prejudices, and the confused testimony of unreliable sources—and place our views about the world on a new, pure, and rock-solid foundation. Descartes splits his meditations up into six parts. In the First Meditation, he describes a once in a lifetime exercise of subjecting all his beliefs to intense doubt. In the Second Meditation, he discusses whether any belief could survive this exercise. If you are interested, the full text of all six of Descartes’ Meditations can be found here.
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.
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.
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.
In the First Meditation, Descartes resolved to subject all his beliefs to a once in a lifetime exercise of intense doubt. He resolved to reject any belief if there was even the smallest chance that he might be wrong about it. This includes everything he seems to remember and everything his senses seem to tell him about the world. Descartes begins his Second Meditation by reminding his readers just how serious his intellectual predicament is.
Meditation 2, Paragraphs 1-2
The Meditation of yesterday has filled my mind with so many doubts, that it is no longer in my power to forget them. Nor do I see, meanwhile, any principle on which they can be resolved; and, just as if I had fallen all of a sudden into very deep water, I am so greatly disconcerted as to be unable either to plant my feet firmly on the bottom or sustain myself by swimming on the surface. I will, nevertheless, make an effort, and try anew the same path on which I had entered yesterday, that is, proceed by casting aside all that admits of the slightest doubt, not less than if I had discovered it to be absolutely false; and I will continue always in this track until I shall find something that is certain, or at least, if I can do nothing more, until I shall know with certainty that there is nothing certain. Archimedes, that he might transport the entire globe from the place it occupied to another, demanded only a point that was firm and immovable; so, also, I shall be entitled to entertain the highest expectations, if I am fortunate enough to discover only one thing that is certain and indubitable.
I suppose, accordingly, that all the things which I see are false (fictitious); I believe that none of those objects which my fallacious memory represents ever existed; I suppose that I possess no senses; I believe that body, figure, extension, motion, and place are merely fictions of my mind. What is there, then, that can be esteemed true? Perhaps this only, that there is absolutely nothing certain.
Descartes observes here that his project has left him without a place to stand, as everything he previously believed seems to have fallen away. He likens this to falling into very deep water. What he hopes to find in the Second Meditation is just one firm foothold: one conclusion that he can hold onto in the face of intense doubt. If he can find just one belief that is certain—one belief that is firm and immovable—then he will have made his first positive step in his grand project of setting scientific knowledge on a solid foundation.
Descartes’ once in a lifetime exercise of intense doubt strikes many as an exciting project. There is something exhilarating about the idea of examining one’s own beliefs so carefully and taking responsibility for one’s own cognitive life. It seems intellectually courageous, perhaps even morally commendable.
However, some philosophers have argued that it provides us with a misleading picture of cognitive improvement. According to these kinds of views, the path towards truth and away from error is not to be found in a once in a lifetime reboot of our own cognitive lives, but in a series of piecemeal improvements. Although we are flawed thinkers, the solution to our predicament is not to tear down our structure of beliefs and rebuild it from the ground floor. Rather, we should make renovations as we go along.
Many philosophers have expressed views along these lines, but it is especially associated with the twentieth century philosopher Otto Neurath, in part because he provided his own striking image of this strategy. In 1921, he wrote:
We are like sailors who on the open sea must reconstruct their ship but are never able to start afresh from the bottom. Where a beam is taken away a new one must at once be put there, and for this the rest of the ship is used as support. In this way, by using the old beams and driftwood the ship can be shaped entirely anew, but only by gradual reconstruction.
It is worth thinking for yourself which view you find more plausible. Do you think that the best way to improve the overall quality of one’s cognitive life is to start from scratch, carefully attending to the strength of one’s foundations, or to engage in a ‘gradual reconstruction’ of the existing structure? Does it make a difference whether we are considering scientific beliefs or everyday beliefs?
The crux of the Second Meditation is Descartes’ claim to have found one belief that he can hold with complete certainty. Descartes claims that he cannot doubt that he exists. Although he might doubt the truth of all the thoughts that come before his mind, and although he might doubt the operation of his rational faculties, he finds that he cannot doubt that he is thinking all these thoughts. In fact, the more he doubts, the more convinced he becomes that he exists! The belief ‘I think, I exist’—or, ‘I am thinking, therefore I exist’—provides him with the foothold that he has been searching for. The belief in one’s own existence is beyond doubt. The remainder of the Meditations explores how much scientific knowledge we might be able to build on this one indubitable belief.
Meditation 2, Paragraph 3
But how do I know that there is not something different altogether from the objects I have now enumerated, of which it is impossible to entertain the slightest doubt? Is there not a God, or some being, by whatever name I may designate him, who causes these thoughts to arise in my mind? But why suppose such a being, for it may be I myself am capable of producing them? Am I, then, at least not something? But I before denied that I possessed senses or a body; I hesitate, however, for what follows from that? Am I so dependent on the body and the senses that without these I cannot exist? But I had the persuasion that there was absolutely nothing in the world, that there was no sky and no earth, neither minds nor bodies; was I not, therefore, at the same time, persuaded that I did not exist? Far from it; I assuredly existed, since I was persuaded. But there is I know not what being, who is possessed at once of the highest power and the deepest cunning, who is constantly employing all his ingenuity in deceiving me. Doubtless, then, I exist, since I am deceived; and, let him deceive me as he may, he can never bring it about that I am nothing, so long as I shall be conscious that I am something. So that it must, in fine, be maintained, all things being maturely and carefully considered, that this proposition, I am, I exist, is necessarily true each time it is expressed by me, or conceived in my mind.
Descartes’ proof of the certainty of the cogito has the reputation of being elegantly simple. So much so, that it can seem as though he arrives at the certainty of this belief through pure intuition. However, we can unpack the argument a little more carefully by setting it out in standard form with clear premises and a conclusion. As you will see, it really is quite simple.
Premise 1: I am thinking at this moment in time.
Premise 2: If I am thinking at this moment in time, I exist at this moment in time.
Conclusion: I exist at this moment in time.
Is this a good argument? It certainly seems to be valid. A valid argument is one in which the premises cannot be true while the conclusion is false, and that is the case here. But on more careful reflection, you might worry that the little word ‘I’ is doing quite a lot of work. One way that an argument can be flawed is if it equivocates on the meaning of a key term; that is, if a term takes on a different meaning in the premises than it does in the conclusion. So quite a bit depends on what Descartes means by ‘I’. Descartes devotes the remainder of the Second Meditation to addressing this topic.
Having latched onto his own existence out of the very deep waters of intense doubt, Descartes now turns his attention to consider more carefully what exactly he is. What is the ‘I’ in ‘I am’? What is this self that he can be certain exists? It is at this point that the Second Meditation takes a slight turn, as Descartes moves from the abstract logic of the cogito, to a more substantial philosophical view about the nature of the self. His answer is that he is a ‘thinking thing.’ In other words: he is a mind.
Meditation 2, Paragraphs 4 and 6
But I do not yet know with sufficient clearness what I am, though assured that I am; and hence, in the next place, I must take care, lest perchance I inconsiderately substitute some other object in room of what is properly myself, and thus wander from truth, even in that knowledge (cognition) which I hold to be of all others the most certain and evident. For this reason, I will now consider anew what I formerly believed myself to be, before I entered on the present train of thought; and of my previous opinion I will retrench all that can in the least be invalidated by the grounds of doubt I have adduced, in order that there may at length remain nothing but what is certain and indubitable….
But [as to myself, what can I now say that I am], since I suppose there exists an extremely powerful, and, if I may so speak, malignant being, whose whole endeavors are directed toward deceiving me? Can I affirm that I possess any one of all those attributes of which I have lately spoken as belonging to the nature of body? After attentively considering them in my own mind, I find none of them that can properly be said to belong to myself. To recount them were idle and tedious. Let us pass, then, to the attributes of the soul. The first mentioned were the powers of nutrition and walking; but, if it be true that I have no body, it is true likewise that I am capable neither of walking nor of being nourished. Perception is another attribute of the soul; but perception too is impossible without the body; besides, I have frequently, during sleep, believed that I perceived objects which I afterward observed I did not in reality perceive. Thinking is another attribute of the soul; and here I discover what properly belongs to myself. This alone is inseparable from me. I am—I exist: this is certain; but how often? As often as I think; for perhaps it would even happen, if I should wholly cease to think, that I should at the same time altogether cease to be. I now admit nothing that is not necessarily true. I am therefore, precisely speaking, only a thinking thing, that is, a mind (mens sive animus), understanding, or reason, terms whose signification was before unknown to me. I am, however, a real thing, and really existent; but what thing? The answer was, a thinking thing.
Sometimes, a philosopher sets themselves the challenge of addressing a particular issue and, along the way, winds up uncovering a handful of interesting ideas related to other philosophical questions. It is like if a prospector set off to mine for gold and inadvertently hit upon a diamond deposit. The Second Meditation is a little bit like that. Descartes wonders whether he can be certain that any of his beliefs are true, and along the way he uncovers several important ideas about knowledge and the mind. One of these philosophical ideas is Dualism.
Dualism about the mind is the view 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. Descartes was a substance dualist, meaning that he held that the human body and the human mind—or more broadly, the physical and the mental parts of the universe—are made of fundamentally different kinds of stuff. The mind is an immaterial ‘thinking thing’ whereas the body is unthinking ‘matter.’
Throughout the next several paragraphs of the Second Meditation, Descartes begins to explore the notion that he is, fundamentally, a thinking thing. He begins to sketch a theory of the human mind, emphasizing some of its main operations. This will eventually lead him to conclude this Meditation on a striking and controversial note (more on that below). For now, it is worth appreciating that he draws a distinction between the operations of the mind and the deliverances of the senses.The basic picture is one in which the senses provide input that needs interpreting. The senses deliver messages that the mind then does the work of judging and understanding. At one point, Descartes makes this point by describing his experience of observing people on the street below his window.
Meditation 2, Paragraph 13
But, meanwhile, I feel greatly astonished when I observe [the weakness of my mind, and] its proneness to error. For although, without at all giving expression to what I think, I consider all this in my own mind, words yet occasionally impede my progress, and I am almost led into error by the terms of ordinary language. We say, for example, that we see the same wax when it is before us, and not that we judge it to be the same from its retaining the same color and figure: whence I should forthwith be disposed to conclude that the wax is known by the act of sight, and not by the intuition of the mind alone, were it not for the analogous instance of human beings passing on in the street below, as observed from a window. In this case I do not fail to say that I see the men themselves, just as I say that I see the wax; and yet what do I see from the window beyond hats and cloaks that might cover artificial machines, whose motions might be determined by springs? But I judge that there are human beings from these appearances, and thus I comprehend, by the faculty of judgment alone which is in the mind, what I believed I saw with my eyes.
Take a moment to reflect on your everyday conscious experience of the world. Focus your attention on a simple object or event in your immediate vicinity. For Descartes, it was observing a piece of wax and looking at people walking through the town square. Perhaps for you, it might be an item on your desk or whatever is happening right outside your window. Can you notice a distinction between the deliverances of your senses and the operations of your conscious mind? Ask yourself: what information do your senses provide, and how does your mind organize and interpret this? If you can notice a difference between seeing and thinking, what is this like? How would you try to describe it?
Let’s take stock. In the Second Meditation, Descartes identifies a belief that he cannot doubt no matter how hard he tries: he is certain that he exists. This leads him to reflect on the nature of the self that is at the heart of his regained certainty. In doing so, he begins to sketch the contours of a theory of the human mind. Descartes concludes by returning to the main question that has interested him since he put forward the cogito: what is this ‘I’ in ‘I am’? He claims that we enjoy a special kind of access to our own mind. Self-knowledge is easier, more reliable, and qualitatively different than our knowledge of the external world.
Meditation 2, Paragraphs 15-16
But finally, what shall I say of the mind itself, that is, of myself? for as yet I do not admit that I am anything but mind. What, then! I who seem to possess so distinct an apprehension of the piece of wax, do I not know myself, both with greater truth and certitude, and also much more distinctly and clearly? For if I judge that the wax exists because I see it, it assuredly follows, much more evidently, that I myself am or exist, for the same reason: for it is possible that what I see may not in truth be wax, and that I do not even possess eyes with which to see anything; but it cannot be that when I see, or, which comes to the same thing, when I think I see, I myself who think am nothing. So likewise, if I judge that the wax exists because I touch it, it will still also follow that I am; and if I determine that my imagination, or any other cause, whatever it be, persuades me of the existence of the wax, I will still draw the same conclusion. And what is here remarked of the piece of wax, is applicable to all the other things that are external to me. And further, if the [notion or] perception of wax appeared to me more precise and distinct, after that not only sight and touch, but many other causes besides, rendered it manifest to my apprehension, with how much greater distinctness must I now know myself, since all the reasons that contribute to the knowledge of the nature of wax, or of any body whatever, manifest still better the nature of my mind? And there are besides so many other things in the mind itself that contribute to the illustration of its nature, that those dependent on the body, to which I have here referred, scarcely merit to be taken into account.
But, in conclusion, I find I have insensibly reverted to the point I desired; for, since it is now manifest to me that bodies themselves are not properly perceived by the senses nor by the faculty of imagination, but by the intellect alone; and since they are not perceived because they are seen and touched, but only because they are understood [or rightly comprehended by thought], I readily discover that there is nothing more easily or clearly apprehended than my own mind. But because it is difficult to rid one’s self so promptly of an opinion to which one has been long accustomed, it will be desirable to tarry for some time at this stage, that, by long continued meditation, I may more deeply impress upon my memory this new knowledge.
Self-knowledge is a fascinating philosophical topic. In the Second Meditation, Descartes argues that one can be certain that one exists, and, furthermore, that our knowledge of our own minds is superior in many ways to our knowledge of the external world. Other philosophers have taken a different view. For example, in 1938 the philosopher Ludwig Wittgenstein wrote, ‘Nothing is so difficult as not deceiving oneself.’ Take this poll to gauge your own view about our powers of self-knowledge.
In Descartes’ Second Meditation, he hopes to show that one special belief can serve as a stable foundation for the entire intellectual project of learning about the world. Throughout his meditation, he makes several ambitious and exciting claims, including that the cogito is indubitable, that the self is the mind, and that self-knowledge is clearer and more fundamental than other types of knowledge.
Whether he is ultimately right or wrong about all of this is a valuable question to think about for yourself. But perhaps what is even more significant than whether he was right or wrong, is that in the short pages of the Second Meditation, Descartes lit a fuse that set off an explosion of fascinating work in Western philosophy. For centuries after Descartes, philosophers debated the very ideas about knowledge and the human mind that you have just explored, often developing them in exciting new directions. We are still feeling the force of this explosion today.
For a quick summary of Descartes’ argument, and how his search for certainty led to the view that he is a thinking thing, check out this video:
If you are curious where the certainty that Descartes believed he had found in the cogito takes him next, pick up the story with his Third Meditation, where he considers whether the cogito can be developed into an argument for the existence of God. And for an overview of how contemporary epistemologists think about self-knowledge and how contemporary philosophers of mind think about dualism, see the articles “The KK (Knowing that One Knows) Principle” and “Dualism and Mind” on the Internet Encyclopedia of Philosophy.
This work has been adapted from Meditations on First Philosophy, a title from the eCampusOntario Public Domain Core Collection. This work is in the public domain. All images were created using Midjourney and are the property of the Philosophy Teaching Library.
Smartt, Tim. 2024. “Knowing Your Own Mind: René Descartes’ Meditations on First Philosophy, Meditation 2.” The Philosophy Teaching Library. Edited by Robert Weston Siscoe, <https://philolibrary.crc.nd.edu/article/knowing-your-own-mind/>.
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.
