I’m on trial for a murder committed five years ago. Taking the stand in my own defense, I declare:
“People of the jury: I’m not the person who committed the murder. That person was angry, but I am calm. That person was under forty years of age, but I’m over forty. That person was married, his favorite food was lasagna, his hair was brown, and he believed people should be punished for offending him. I, on the other hand, am divorced, prefer tacos, have grey hair, and I let people who offend me go their own way. So you see, I’m not the same person as the person who committed the murder, and you can’t justly punish the wrong person for a crime.”
Would any jury take my testimony as a good reason to acquit me? Let’s hope not! But, what was wrong with my testimony? Both my bodily states and my mental states have changed radically in the last five years. If I’m mentally and physically so different from the murderer five years ago, then how can we be the same person? If there’s something that’s me that remains the same across time, what is it? If there’s nothing that’s me that remains the same over time, then how could I be the same person at different times?
These questions challenge a deeply held assumption we have about ourselves. All our meaningful human interactions presuppose that persons persist across time. You assume the person you say “goodbye” to on the phone is the same person you said “hello” to earlier. When you plan for the future, you assume you’re making plans for your future self, not someone else. When we think justice is done in a criminal trial, we assume the person put into prison is the very same person as the person who committed the crime months or years earlier. But here is a mystery: how can one’s person remain the same over time when one’s mind and body are constantly changing?
In this reading, we will examine one of history’s most influential answers: the psychological continuity theory of the Early Modern philosopher John Locke.
John Locke (1632-1704) was a British philosopher, medical researcher, and Oxford academic. A prominent Enlightenment thinker during a tumultuous century of political and religious conflicts, Locke made substantial contributions to political theory and philosophy. His reason-based, anti-authoritarian political thought, which was instrumental in both English and American revolutions, championed citizen-focused sovereignty and the separation of church and state. In philosophy, Locke contributed an empirical (i.e., senses-based) theory of knowledge in his monumental An Essay Concerning Human Understanding, in which he attempts to find the limits of human understanding with respect to a wide range of topics, including personal identity. His definition of “person”, as well as his memory-based theory of personal identity across time, remain highly influential.
The version of Locke’s An Essay Concerning Human Understanding, Book 2, Chapter 27 (“Of Identity and Diversity”) that you will be reading from can be found here.
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.
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.
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.
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.
Immaterial Soul – A personal thinking substance without any physical constitution.
Locke includes essential aspects of his theory of personal identity across time in the following passage.
Section 9
To find what personal identity consists in, we must consider what ‘person’ stands for. I think it is a thinking intelligent being, that has reason and reflection, and can consider itself as itself, the same thinking thing in different times and places. What enables it to think of itself is its consciousness, which is inseparable from thinking and (it seems to me) essential to it. It is impossible for anyone to perceive, without perceiving that he perceives. When we see, hear, smell, taste, feel, meditate, or will anything, we know that we do so. It is always like that with our present sensations and perceptions. And it is through this that everyone is to himself that which he calls ‘self’…. Consciousness always accompanies thinking, and makes everyone to be what he calls ‘self’ and thereby distinguishes himself from all other thinking things; in this alone consists personal identity, i.e. the sameness of a rational being; and as far as this consciousness can be extended backwards to any past action or thought, so far reaches the identity of that person; it is the same self now that it was then; and this present self that now reflects on it is the one by which that action was performed.
Here, Locke makes three important points. First is his highly influential definition of “person”. A person, he says, is an intelligent being who is not only conscious but also self-conscious with the power of reason and memory, including the power to remember itself at various times and places. As he points out in a later section, he is defining “person” in a forensic sense (i.e., pertaining to the justice of praise, blame, reward, or punishment): only someone with such abilities could be morally praiseworthy or blameworthy, or be an appropriate defendant in a criminal trial.
Second, Locke points out that what gives us our sense of self is our self-consciousness. We are aware of ourselves as beings who think, sense, will, and remember ourselves as doing things in the past. Our sense of self is thus first-personal. He concludes that the identity of one’s person is determined by one’s first-person consciousness.
Third, Locke says that one’s being the same person at different times just is a relation of first-person consciousness across time. And it is memory that connects one’s consciousness now to one’s conscious experiences in the past. Hence, first-person memory provides the psychological continuity that unites a person at different times into one and the same person.
Thus we get Locke’s theory: personal identity across time consists entirely in a relation of first-person consciousness via memory across time. It follows that you’re the same person who existed in the past if, and only if, you can remember some first-person conscious experience that the person in the past had.
To appreciate why Locke defines “person” as he does, consider the following two scenarios: (i) A cat, which has scratched you, is tried in a criminal court for assault and battery; (ii) A father is feeding his infant some baby formula when the infant moves her head and the bottle tips downward, spilling liquid onto the father’s clothing. The father puts his infant into the corner, adding, “You bad baby. You’re in time-out to think about what you’ve done!” Questions: How does Locke’s theory explain why putting the cat on trial is absurd? What would Locke say that the father fails to understand about his infant?
Locke thinks we can easily mistake personal identity for other kinds of identity by confusing the word “person” with words like “human” and “substance”.
Section 7
To conceive and judge correctly about identity, we must consider what the idea the word it is applied to stands for: it is one thing to be the same substance, another the same man [Locke means “human”], and a third the same person, if ‘person’, ‘man’, and ‘substance’ are names for three different ideas; for such as is the idea belonging to that name, such must be the identity. If this had been more carefully attended to, it might have prevented a great deal of that confusion that often occurs regarding identity, and especially personal identity […]
Locke knew that some people assume a person just is a human or a substance (e.g., an immaterial soul). By paying attention to the differing ways we use the words “person”, “human” and “substance”, Locke thinks, we’ll realize that personal identity differs from both human identity and substance identity.
What makes something the same human across time? Human identity, Locke says, is comparable to oak tree identity. We don’t identify the same oak tree at different times by comparing its substance (it’s material parts) at different times.
Section 4
How, then, does an oak differ from a mass of matter? […] [T]he mass is merely the cohesion of particles of matter ]…], whereas the oak is such a disposition of particles as constitutes the parts of an oak, and an organization of those parts that enables the whole to receive and distribute nourishment so as to continue and form the wood, bark, and leaves, etc. […] Thus something is one plant if it has an organization of parts in one cohering body partaking of one common life, and it continues to be the same plant as long as it partakes of the same life, even if that life is passed along to new particles of matter vitally united to the living plant.
Locke concludes that oak tree identity across time does not require substance identity across time. What makes the large oak and the sapling the same tree is that the two have the same organizing structure of parts in one cohering body partaking of one common biological life.
Suppose you plant an oak tree sapling today. Fifty years later you return with your children (maybe grandchildren!) and announce: “There’s the oak tree I planted fifty years ago!” What you say is true, but the great oak is not the same mass of material parts as the sapling. Indeed, the great oak has many more substantive parts than the sapling had; and yet is the same oak tree. So, an oak tree’s identity across time depends not on its being the same substance, but rather on its organizing structure of parts.
Locke says that something similar to oak tree identity goes for human identity.
Section 6
This also shows what the identity of the same man [i.e., “same human”] consists in, namely: a participation in the same continued life by constantly fleeting particles of matter that are successively vitally united to the same organized body. If you place the identity of man in anything but this, you’ll find it hard to make an embryo and an adult the same man, or a well man and a madman the same man.
Locke’s point is that human identity across time is not the sameness of physical substance across time but is rather the sameness of human organizing structure of parts across time. After all, you’re the same human being as a baby who existed long ago, but your body’s substantive parts are radically different from any baby’s substantive parts.
Our biology seems to bear out Locke’s idea. We now know that most of our physical human parts (cells) are replaced every few months and almost all our cells are replaced during our lifetimes. But we remain the same human being from infancy to old age. Today we might say that your human DNA expresses the special organizing structure that makes you the same human being at different times.
But why isn’t human identity the same as personal identity? Aren’t all humans persons, and aren’t all persons humans? Locke has an intriguing answer.
Section 8
[…] [T]here should be no doubt that the word ‘man’ as we use it stands for the idea of an animal of a certain form. The time-hallowed definition of ‘man’ as ‘rational animal’ is wrong. If we should see a creature of our own shape and physical constitution, though it had no more reason all its life than a cat or a parrot, we would still call him a man; and anyone who heard a cat or a parrot talk, reason, and philosophize would still think it to be a cat or a parrot and would describe it as such. One of these is a dull, irrational man, the other a very intelligent rational parrot.
Locke here points out that a human might be so devoid of personal powers that it would be at the cognitive level of a cat. But, cats lack the cognitive abilities required for forensic personhood. Thus, a human with severely diminished cognitive powers—such as someone in a persistent vegetative state—lacks the cognitive abilities required for (forensic) personhood. This is why we will never (let’s hope) see someone in a persistent vegetative state stand trial in a criminal case, for such a human would not be able to understand, or even be conscious of, any of the trial’s proceedings. Such facts explain why Locke’s forensic definition of “person” does not include being human: not all humans are (forensic) persons; and there might even be persons who aren’t human!
Locke’s definition allows for the possibility that there are non-human persons. Is this plausible? Well, suppose representatives of an alien civilization from outer space were to visit earth and begin to kill humans to steal our resources. If those aliens satisfied Locke’s definition of person, then couldn’t they deserve moral blame for their behavior, even though they are not human at all?
Locke is aware that some people think a person just is an immaterial soul (a non-physical, conscious, thinking substance). Locke himself is open to the possibility that our first-person consciousness is attached to an immaterial soul. So, Locke is not opposed to what we might call the soul theory of personhood. But (and it’s a big but!), Locke thinks it’s a mistake to think that personal identity across time just is having the same soul.
Section 10
[…] [T]he question is about what makes the same person, and not whether the same identical substance always thinks in the same person. Different substances might all partake in a single consciousness and thereby be united into one person, just as different bodies can enter into the same life and thereby be united into one animal, whose identity is preserved throughout that change of substances by the unity of the single continued life. What makes a man be himself to himself is sameness of consciousness, so personal identity depends entirely on that—whether the consciousness is tied to one substance throughout or rather is continued in a series of different substances. For as far as any thinking being can repeat the idea of any past action with the same consciousness that he had of it at first, and with the same consciousness he has of his present actions, so far is he the same personal self. For it is by the consciousness he has of his present thoughts and actions that he is self to himself now, and so will be the same self as far as the same consciousness can extend to actions past or to come. Distance of time doesn’t make him two or more persons, and nor does change of substance: any more than a man is made to be two men by having a long or short sleep or by changing his clothes.
Consider Locke’s analogy: as someone can be the same human across time despite changes in the human’s bodily substance (material parts), so might someone be the same person across time despite changes in the thinking substance that consciousness is attached to. Locke’s central idea is that the crucial personal link—the link that relates a person at one time to the same person at a different time—is first-person conscious experience and nothing else. It’s irrelevant, he thinks, whether the thinking substance that is conscious now is the same identical thinking substance as one in the past.
Suppose that in the future there will be, as some people (and some sci-fi movies) predict, silicon-based persons (i.e., persons made of silicon, rather than flesh and blood). And suppose that someday such a person will be able to remember your current conscious experience as you’re reading this (perhaps advances in artificial intelligence, computer technology, and neuroscience will make “uploading” first-person conscious experiences possible). Were this to happen, Locke’s theory implies that this silicon-based person would be you.
Thomas Reid, an Early Modern philosopher who was born shortly after Locke’s death, objected that Locke’s theory allows a contradiction to be true (Reid’s objection from Essays on the Intellectual Powers of Man, Essay III, Chapter 6, can be found here).
Imagine three events in a man’s life: when he was (A) a school boy he was whipped for robbing, when (B) a young officer he stole the enemy’s flag in battle, and when (C) an old man he was decorated as a general. When he stole the flag, he remembered being whipped as a school boy, and when he was decorated as a general he remembered stealing the flag as a young officer, but he could no longer remember being whipped as a school boy.
PERSON EVENT
A School boy is whipped for robbing
B Young officer takes the enemy’s flag in battle
C Old man is decorated as a general
On Locke’s theory, A = B (because B remembers being A) and B = C (because C remembers being B); it follows by transitivity that A = C. However, C cannot remember being whipped as a school boy; so, Locke’s theory implies that A ≠ C; therefore (A = C) & (A ≠ C), which is a contradiction. But, contradictions can’t be true, right? A video presentation of this objection is available here.
A common assumption among soul theorists about personhood (i.e., those who think a person just is an immaterial soul) is that personal identity across time is just the continuous existence of an immaterial soul substance across time. Accordingly, you (the person) have existed as long as your soul has existed, and you’ll persist as the same person as long as your soul exists. Although Locke is open to the possibility that our consciousness is attached to an immaterial soul, he thinks it’s a mistake to identify soul existence across time with personal identity across time. Locke presses his point with a thought experiment.
Section 14
Reflect on yourself, and conclude that you have in yourself an immaterial spirit that is what thinks in you, keeps you the same throughout the constant change of your body, and is what you call ‘myself’. Now try to suppose also that it is the same soul that was in Nestor or Thersites at the siege of Troy. This isn’t obviously absurd; for souls, as far as we know anything of their nature, can go with any portion of matter as well as with any other; so the soul or thinking substance that is now yourself may once really have been the soul of someone else, such as Thersites or Nestor. But you don’t now have any consciousness of any of the actions either of those two; so can you conceive yourself as being the same person with either of them? Can their actions have anything to do with you? Can you attribute those actions to yourself, or think of them as yours more than the actions of any other men that ever existed? Of course you can’t […]
To focus Locke’s point, suppose that during the ancient siege of Troy, Nestor committed a heinous war crime—say, he killed a defenseless baby—but was never held morally accountable. Now, suppose the police arrive to arrest you for the murder. What will you say? Probably something like: “Are you crazy? You’ve got the wrong person! I’m not the one who did it!” You will say this because you have no memory whatsoever of killing a baby (right?!). There’s nothing about your consciousness that relates you to the murderer. Nevertheless, on the soul theory of personal identity across time, you are the person who murdered the baby. But, can you really think of yourself as deserving moral blame and punishment?
Variation 1 (Unremembered Recent Murder): You might think our murder example is irrelevant because the supposed crime occurred 3,000 years ago. But, Locke would make the same point about a murder committed a year ago (or last week). Suppose you (an immaterial soul, as we’re supposing) murdered someone last year, but then you permanently lost all your previous memories. If the police arrested you today, what would you say? “Are you crazy? You’ve got the wrong person! I’m not the one who did it!”. You’ll think this because you literally cannot remember doing it. You are no more connected by consciousness to the murderer than is some randomly selected neighbor down the street.
Variation 2 (Remembered Murder): Now suppose you do remember murdering someone last year, and the police arrive to arrest you. What will you think? Perhaps something like: “What took you so long?” In this scenario you really do think of yourself as guilty because you remember committing the crime. Accordingly, you could make sense of the moral blame and punishment that might come your way, because you’re connected to the crime by your own memory of a past, first-person experience, and thus you have the psychological continuity with the murderer that Locke says unites conscious beings into the same person across time
Locke points out that his account of personal identity across time is consistent with (i.e., it logically allows for) personal life after death. Suppose that someone in the future after your death remembers an experience you’re having right now. According to Locke’s theory, that future person will be you. Using the language of the Christian doctrine of the resurrection of the body, Locke says the following.
Section 15
So we can easily conceive of being the same person at the resurrection, though in a body with partly different parts or structure from what one has now, as long as the same consciousness stays with the soul that inhabits the body. But the soul alone, in the change of bodies, would not be accounted enough to make the same man—except by someone who identifies the soul with the man. If the soul of a prince, carrying with it the consciousness of the prince’s past life, were to enter and inform the body of a cobbler, who has been deserted by his own soul, everyone sees that he would be the same person as the prince, accountable only for the prince’s actions; but who would say it was the same man? The body contributes to making the man, and in this case I should think everyone would let the body settle the ‘same man’ question, not dissuaded from this by the soul with all its princely thoughts. To everyone but himself he would be the same cobbler, the same man.
In this reflection on the afterlife, Locke argues that mere sameness of soul across time does not guarantee sameness of person. For if the prince’s soul but not his consciousness were transferred into the cobbler’s body, that would be insufficient to make the prince the person inhabiting the cobbler’s body. After all, that person would not think of himself as the prince; he would have no memories of being the prince, and thus it would be unjust to hold him accountable for the prince’s actions.
But, suppose the prince’s consciousness (including all his memories) were transferred with the prince’s soul into the cobbler’s body. Then, it would be plausible that the prince is the person inhabiting that body. He would surely think of himself as the prince. If you asked him who his mother was, he’d have warm fuzzy thoughts, feelings, and memories of the Queen. Of course, everyone who was ignorant of this consciousness transfer would think that he remained the cobbler, but this is because we are accustomed to psychological continuity accompanying human identity.
Suppose that after your death your soul is in heaven but it cannot remember any of your experiences. Would that soul be you? Why would you care whether there is some person in heaven who happens to have the same soul as you if that person has no personal connection—no psychological continuity—with you? As far as hoping there will be good things in your future, what would be the relevant difference between that soul, who can’t remember you at all, and a different person’s soul (say, someone you’ve never met) existing in heaven?
All the crucial elements of Locke’s view are in the following passage.
Section 16
But although the same immaterial substance or soul does not by itself, in all circumstances, make the same man, it is clear that consciousness unites actions—whether from long ago or from the immediately preceding moment—into the same person. Whatever has the consciousness of present and past actions is the same person to whom they both belong. If my present consciousness that I am now writing were also a consciousness that I saw an overflowing of the Thames last winter and that I saw Noah’s ark and the flood, I couldn’t doubt that I who write this now am the same self that saw the Thames overflowed last winter and viewed the flood at the general deluge—place that self in what substance you please. I could no more doubt this than I can doubt that I who write this am the same myself now while I write as I was yesterday, whether or not I consist of all the same substance, material or immaterial. For sameness of substance is irrelevant to sameness of self: I am as much involved in—and as justly accountable for—an action that was done a thousand years ago and is appropriated to me now by this self-consciousness as I am for what I did a moment ago.
In our ordinary experience our first-person consciousness goes along for the ride as our human bodies age. But real examples of serious amnesia (e.g., Alzheimer’s disease) show that, no matter what our consciousness is attached to, psychological continuity can be, and sometimes is, diminished or extinguished. And that’s why Locke concludes that even the literal sameness of soul substance across time is insufficient for sameness of person across time. What matters, Locke urges, both for your sense of self and for the justice of praise, blame, reward, or punishment, is a relation of personal consciousness, whether that connects whatever you are now to whatever you were a minute ago or to whatever you might be a billion years from now.
In Franz Kafka’s novella The Metamorphosis, Gregor Samsa, a salesman, wakes up one morning to find that he has the body of a “monstrous vermin”, such as a cockroach. It’s a horrible situation, as he and his family struggle to adjust to his plight. But, suppose this were to happen to you! You’d be horrified, and you’d wonder how it could have happened; but you wouldn’t doubt that you were the person who was formerly human and is now an insect. Kafka’s story thus illustrates the plausibility of Locke’s idea that psychological continuity is essential to personal identity.
Locke knew how counterintuitive it would seem to say that personal identity across time is not about sameness of thinking substance (material or immaterial) across time. His major contribution was in illuminating how important psychological continuity is for our deserving praise, blame, reward, or punishment. Locke concluded that, regardless of what our consciousness is attached to—whether an immaterial soul or material brain or anything else—it is a relation of first-person consciousness that unites thinking beings across time into one and the same person. Thus, the relation we have to ourselves in the past via memory is crucial for our being justly accountable for our past actions.
To appreciate (i) the importance of personal identity across time, and (ii) what we’re looking for as philosophers as a solution to our mystery, check out this video by a philosopher:
Locke’s groundbreaking work motivated a vast philosophical literature on personal identity across time. For an overview see “Personal Identity” in The Internet Encyclopedia of Philosophy. For more on Locke’s view see “Locke on Personal Identity” in the Stanford Encyclopedia of Philosophy.
This work has been adapted from John Locke, An Essay Concerning Human Understanding, Book 2, Chapter xxvii, in the version presented here. This work is in the Public Domain. All images were created using Midjourney.
Long, Todd R. 2025. “You Are Who You Remember: John Locke’s An Essay Concerning Human Understanding, Book 2, Chapter 27.” The Philosophy Teaching Library. Edited by Robert Weston Siscoe, <https://philolibrary.crc.nd.edu/article/who-you-remember>
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.
