An Essay Concerning Human Understanding
John Locke
About this work
Locke's , published in 1689, is the founding text of British empiricism. Its governing claim is negative: the mind at birth contains no innate ideas, no principles stamped on the soul before experience begins. Everything we know arrives through sensation or reflection, and the task of philosophy is to trace our ideas back to these sources and to mark the boundaries of what we can and cannot know.
Book I demolishes innate ideas. Books II and III do the constructive work. Book II catalogs the materials of thought: simple ideas received passively from sensation (color, sound, solidity) and from reflection (thinking, willing), then complex ideas formed by the mind's own activity (substances, modes, relations). Locke's treatment of personal identity, placed here among the chapters on identity and diversity, defines the self as continuity of consciousness rather than continuity of substance. Book III takes up language: words are signs of ideas, not of things, and much confusion in philosophy arises from treating them otherwise. The theory of abstract ideas and the doctrine of nominal versus real essence lay groundwork that Berkeley and Hume will contest within a generation.
Book IV defines knowledge as the perception of agreement or disagreement among ideas and distinguishes it from probable opinion. The range of genuine knowledge turns out to be narrow; most of what we call knowledge is really well-founded belief. Locke is candid about this, and the candor is the point. The Essay does not so much limit human understanding as map it honestly, separating what reason can establish from what it cannot, and directing inquiry toward where it is likely to bear fruit.
Appears in 37 ideas
Epistemology/Philosophy of Mind
Theology
Science
- AnimalWhat distinguishes the animal from the plant and the human, and what is the nature of animal life?
- MedicineIs medicine an art or a science, and what is the relation of health to disease?
- ElementWhat are the basic building blocks of the physical world, and how do they combine to form complex things?
Ethics
Metaphysics
- FormWhat makes a thing the kind of thing it is: an intelligible pattern, an indwelling principle, or a structure imposed by the mind?
- MatterWhat is matter, the stuff of the physical world, and how does it relate to form, mind, and change?
- SpaceIs space a thing in itself, a property of bodies, or a form of the mind?
- RelationDo things exist in themselves, or only in their connections to other things?
- Same and OtherWhat makes things the same, and what makes them different?
- QualityAre the qualities we perceive in things real properties of nature, or projections of the mind?
- QuantityIs quantity the measure of reality, and how does the quantitative differ from the qualitative?
Epistemology
- KnowledgeWhat can we know, and how do we come to know it?
- LanguageIs language a natural expression of thought or a conventional system that shapes what we can think?
- ExperienceIs experience the source of all knowledge, or does the mind bring something of its own?
- WillIs the will free, and if so, what is the nature of its freedom?
- RhetoricWhat is the art of persuasion, and can it serve truth as well as power?
- Memory and ImaginationHow do memory and imagination extend experience beyond the present, and what do they reveal about the mind?
- OpinionHow does opinion differ from knowledge, and what authority does it deserve?
- IdeaWhat is an idea, and how does it relate to the things we claim to know?
- JudgmentWhat is it for the mind to affirm or deny, and how do we distinguish sound judgment from error?
- SenseWhat do the senses contribute to knowledge, and where do they fall short?
- PrincipleWhat are the starting points of knowledge and reality, and how do we know them?
- ReasoningHow does the mind move from what it knows to what it does not yet know?
- Sign and SymbolHow do signs and symbols carry meaning, and what is the relation between words, ideas, and things?
- MathematicsWhat is the nature of mathematical objects, and why does mathematics apply to the physical world?
Logic & Method
- LogicWhat are the rules that govern valid reasoning, and is logic a science, an art, or both?
- InductionHow does the mind move from observed particulars to universal truths, and can this move ever be rationally justified?
- DefinitionDoes a definition state the nature of a thing, the meaning of a word, or merely the purpose for which we classify it?
- Universal and ParticularDo universals exist independently of particular things, or are they only names we apply to collections of similar individuals?