Philosophy Glossary: Key Terms in Metaphysics, Epistemology and Ethics

Doxa versus Alētheia: In Parmenides, the path of truth (alētheia) is the path of reason, which rejects multiple and changing information as false and affirms the unity and permanence of being. The path of opinion (doxa), by contrast, relies on the senses and accepts multiple, changing appearances as real, without achieving necessary knowledge.

Substantial change: A type of change that transforms a thing completely, changing its very substance. Its two principal forms are birth and death.

Catharsis: Purification.

Categories: Pure a priori concepts of the understanding that make synthetic judgments a priori possible, and that underpin empirical science and its claim to objectivity. The categories apply to the contents of experience or sensible intuitions, shaping knowledge. The most notable are causality and substance. As Kant states, without intuitions concepts are empty, and without concepts intuitions are blind.

Efficient cause: In Aristotle, one of the four types of explanatory factors, the cause or causes of the initial movement of a change, its engine.

Final cause: In Aristotle, another of the four factors of change. It is the objective purpose or end toward which the agent of a change is directed.

Formal cause: In Aristotle, one of the four types of explanatory factors. It is the structure or organization adopted by the substrate at the end of a change.

Material cause: In Aristotle, one of the four types of explanatory factors. It is the substrate or subject of change, the element that undergoes the transformation.

Cynicism: A philosophical movement in ancient Greece that aspired to individual happiness through self-sufficiency, rejecting social conventions and human artifice, and criticizing civilization. Diogenes of Sinope (413-327 BC) is considered its greatest representative.

Knowledge: The activity whereby the mind comes to learn or grasp an object in some way.

Constant conjunction: In Hume's words, when two things are regularly found together, as when a woman is regularly seen with a child, we come to imagine that the first is always followed by the second. In no case do we perceive a necessary connection, only the constant association of the events.

Necessary connection: Traditionally, the conditions of causality (temporal priority and contiguity) are essential but do not by themselves establish the relation. For Hume, the idea of necessary connection is very important: it arises not from any sensory impression of the cause producing the effect, but from the habit of the mind.

Consciousness: A mental faculty consisting in the awareness of one's own activities.

Contingency: The condition of that which exists only by chance. The term opposes necessity: a contingent being could act otherwise or not exist at all.

Cosmogony: A religious, mythological, or philosophical account of the origin of the world and humanity.

Cosmology: The study of the cosmos or universe. Rational cosmology, grounded in scientific observation, physical astronomy, and philosophy, seeks to explain the natural structure of the universe.

Cosmopolitanism: A doctrine that considers all human beings as citizens of the world, regardless of nationality, race, or state, with the world (kosmopolis) as the true homeland.

Cosmos: A Greek term meaning universe, total order and harmony, as opposed to chaos.

Worldview: A set of answers about human reality, the world, and its general nature.

Cratos: Power or strength. Together with demos (people), it forms the word democracy.

Creationism: A doctrine or conception, generally of religious character, holding that the world and its inhabitants were totally created by a being or deity with a specific purpose.

Christianity: A monotheistic religion originating in Judaism, with Jesus of Nazareth as its founder and central figure. His followers believe that Jesus, also called the Messiah or Christ, is the Son of God.

Guilt: A feeling of regret for not having been able to do or be something, or for having done wrong.

Culture: The set of customs, habits, and values of a community, together with the mechanisms of social transmission.

Deduction: A form of knowledge that proceeds from one piece of knowledge to another, whereby the truth of the conclusion depends on the truth of the premises from which it is derived. Intuition is necessary in deduction, since the truth of the conclusion depends on the premises that are known by intuition.

Demiurge: In Plato's Timaeus, an artisan god who shapes the material world from pre-existing matter according to the perfect Forms. He is not a creator from nothing, but a divinity limited to ordering the chaotic material.

Citizenship: The set of rights and duties of members of a state. Together with cratos, it forms democracy.

Displacement: In psychoanalysis, the mechanism by which the affective charge of one idea or object is transferred to another. It operates in dreams, where the manifest content may conceal the latent content, and in the deep structure of the mind.

Determinism: A philosophical and scientific doctrine holding that all phenomena obey necessary laws, such that everything that happens is caused by prior conditions according to universal laws.

Dionysian: In Nietzsche's philosophy, a principle representing the unity of the world and the dissolution of individual differences. It is most clearly manifested in non-figurative art such as music and dance.

Double truth: A doctrine prevalent during the Middle Ages holding that the conclusions of reason (based on philosophical reasoning) and the revelations of faith (based on religious belief) can both be true, even when they appear contradictory.

Dogma: A set of beliefs in religious or political doctrines that cannot be modified and must be accepted by members of a community. A dogma is a truth affirmed or believed as indisputable. In epistemology, dogmatism refers to the belief that reason alone is capable of attaining truth.

Law: A set of norms that regulate behavior in a given society.

Natural law: The idea that there are rules or principles prior to human legislation, whether derived from nature (physis), religious belief, or human reason. Positive law, by contrast, is the set of laws enacted by parliaments in different countries.

Methodical doubt: In Descartes, the procedure of systematically doubting anything questionable, rejecting as false whatever can be imagined as doubtful, as a first step toward certainty.

Moral emotivism: The view that moral judgments express emotions and feelings, which constitute the origin of morality.

Empirical: Relating to what is tested, verified, or confirmed through observation and experience.

Empiricism: A current of modern thought holding that knowledge fundamentally derives from the senses and experience.

Epistemological empiricism: The principle that all ideas must be derived from sensory impressions. Ideas that cannot be traced to such impressions are considered meaningless.

Psychological empiricism: The principle that every idea is a copy of some prior impression. This rejects innate ideas, since all experience presupposes earlier experience.

Incarnation: A theological term referring to the belief that the divine became human in the person of Jesus Christ.

Being: Existence itself, what is.

Being-and-nothingness: In Sartre's thought, the fundamental tension between being-in-itself and being-for-itself, central to his conception of human freedom.

Existentialism: A philosophical current, associated with Sartre, which holds that human beings define themselves through their free choices and actions, rather than through a pre-given essence.

Epicureanism: A philosophical school that identifies happiness as the supreme good of human life, grounded in natural pleasure and friendship, understood as the absence of pain and disturbance.

Epistemology: The branch of philosophy that investigates the nature, scope, and foundations of knowledge, especially its justification and validity. It is also called gnoseology, the theory of knowledge.

Skepticism: An epistemological position questioning the possibility of certain knowledge, the existence of truth, or the reliability of reason. In ethics, skeptics advocated suspension of judgment (epochē) as a means to achieve tranquility of mind and happiness.

Skepticism in philosophy: Philosophy culminates in skepticism. A moderate skepticism can be positive, fostering inquiry within achievable limits. Human knowledge, according to this view, is essentially abstract and mathematical, composed of relations between ideas, while matters of fact and existence are known empirically through sensory experience.

Scripture: A term used for the sacred writings of the Bible, the canonical books of Judaism and Christianity.

Essence: That which a thing is in itself; the fundamental nature of a being.

Being: That which exists.

State of nature: A philosophical concept referring to the original condition of human beings before the establishment of the state, its institutions, and the laws derived from it. This concept appears in many thinkers, including Aristotle, Hobbes, Locke, and Rousseau.

Civil society: A concept opposed to the state of nature, referring to the stage in which human beings organize themselves into institutions that regulate social and political relations.

Status: The social position an individual occupies within society.

Aesthetics: The branch of philosophy that studies and reflects on questions related to beauty and art in general.

Stoicism: A philosophical school that identifies happiness with living in accordance with nature and reason, accepting with equanimity what cannot be changed. The Stoic sage is impassive and indifferent to suffering and pleasure.

Eternal return: In ancient Stoic cosmology, the belief that history repeats itself endlessly in cycles of destruction and regeneration under universal divine providence (pronoia). Nietzsche considered eternal return a supreme test: the affirmation of all that has been and will be, accepting that every moment recurs infinitely.

Ethics: The philosophical reflection on the foundations of morality.

Formal ethics: Ethics concerned with the conditions of moral behavior, rather than its specific content.

Material ethics: Ethics concerned with the content of moral action, including the concrete goods and norms that guide individual conduct.

Ethnocentrism: The attitude of taking one's own culture as the standard for judging and evaluating other cultures.

Eudaimonia: A Greek term referring to happiness as the highest good. Literally, it means having a good spirit, a state of flourishing achieved through virtue.

Evidence: In Descartes, the primary method of knowledge and the criterion of truth. A proposition is true when it is evident, meaning clear and distinct to the mind.