Philosophy

Critical thinking: principles, skills, history, and practical uses Critical thinking Critical thinking is the disciplined process of evaluating information and arguments for accuracy, relevance and logic. This article explains core skills, methods, history, and eve…

Crossing the Rubicon Crossing the Rubicon is an idiom for making an irreversible decision, derived from Julius Caesar’s unauthorized crossing of the Rubicon River in 49 BCE, which helped trigger civil…

Cynics (ancient Greek philosophical school) Cynic Ancient philosophical movement urging virtue in accordance with nature, personal austerity, and rejection of conventional desires. Key figures include Antisthenes and Diogenes; inf…

Cynicism: Ancient Greek School and Modern Attitude Cynicism Cynicism is both an ancient Greek school of thought advocating ascetic virtue and a modern label for skepticism about human motives. This article explains its origins, teachings, p…

Dallas Willard: Philosopher and Writer on Christian Spiritual Formation Dallas Willard Overview of Dallas Willard (1935–2013), his philosophical work in phenomenology, academic career at USC, major books on spiritual formation, and influence on contemporary Christian…

Dariush Shayegan — Iranian philosopher, cultural theorist and public intellectual Dariush Shayegan Dariush Shayegan (1935–2018) was an Iranian philosopher and cultural theorist who explored East–West dialogue, Persian mysticism and modernity; he wrote in Persian and French and f…

Decision (choice and judgment) Decision A decision is the act of selecting among alternatives or issuing a formal determination. Covers components, theories, types, methods, legal and computational meanings, psychologica…

Deconstruction: a method for analyzing texts and meanings Deconstruction Deconstruction is a critical approach that studies how texts and cultural works generate meaning by exposing assumptions, tensions, and binary oppositions. It originated in 20th-ce…

Democritus — Ancient Greek Philosopher and Founder of Atomism Democritus Democritus (c.460–c.370 BC) of Abdera advanced early atomism: a naturalistic view that matter consists of eternal, indivisible atoms moving in empty space, influencing later scient…

Denis Diderot: French Enlightenment Philosopher and Encyclopedist Denis Diderot Denis Diderot (1713–1784) was a French philosopher, writer and art critic who co‑founded and edited the Encyclopédie. He influenced Enlightenment thought, literature and criticism…

Denying the Correlative (logical fallacy) Denying the correlative A logical fallacy that attempts to introduce a third option where two mutually exclusive and jointly exhaustive alternatives exist; explained with examples, causes, and how it diff…

Derek Parfit: life and philosophical contributions Derek Parfit British moral philosopher Derek Parfit (1942–2017) reshaped debates on personal identity, rationality, ethics and population problems through influential works such as Reasons and…

Derivation Derivation is the process of producing something from an existing source; the term appears across language, mathematics, science, law, and finance with related but distinct meaning…

Designer baby: concepts, methods, and ethical questions Designer baby Overview of the concept of 'designer babies' including scientific methods (IVF, PGD, gene editing), potential applications, history, and ethical, legal, and social concerns.

Determinism: philosophical and scientific perspectives Determinism Determinism is the view that events are governed by prior conditions or laws. This article surveys types of determinism, historical development, scientific role, implications for f…

Dialectic: Method, History, and Applications in Philosophy Dialectic Dialectic is a method of structured dialogue and reasoning used to explore contradictions and arrive at better-supported conclusions across philosophy, logic, and other fields.

Dignitas — Roman concept of personal standing and authority Dignitas Dignitas was a Roman idea denoting a man's accumulated reputation, moral worth, and claim to respect. It shaped political behavior, social rank, and rhetorical appeals in the Repub…

Dignity: Meaning, Origins, Social Role, and Contemporary Debates Dignity An overview of human dignity: its meanings, philosophical and legal roots, historical development, roles in law and ethics, and key controversies about its scope and application.

Dilemma: meaning, types, and logical formulations Dilemma A dilemma presents two or more alternatives that lead to different outcomes. This article explains everyday and formal meanings, types (constructive, destructive, trilemma), histor…

Discipline: Principles, Types, History and Practical Applications Discipline An overview of discipline: definitions, types (self, parental, institutional, military), historical context, uses in education and work, methods, and distinctions between punishmen…

Distortion Overview of distortion as change or corruption of form, signal, data or perception; types, causes, measurement, history, practical uses and notable distinctions.

Dualism: concepts, varieties, and significance in thought Dualism Dualism is the view that a thing or domain is fundamentally composed of two distinct kinds or substances. This article explains its forms, history, examples, and how it contrasts w…

Dukkha: The Buddhist concept of suffering and unsatisfactoriness Dukkha Dukkha is a foundational Buddhist idea often rendered as suffering or unsatisfactoriness. It names the pervasive unsatisfactory quality of conditioned life and points toward causes…

Duty (moral obligation, responsibility, and social role) Duty Duty: the moral or legal obligations that guide actions toward others, communities, roles, and principles. Covers definitions, types, history, ethical theories, examples, and how c…

Edmund Husserl: Founder of Phenomenology Edmund Husserl A concise account of Edmund Husserl's life, philosophical method, major ideas, academic background and lasting influence as the founder of phenomenology.

Egalitarianism: Principles, Forms, and Historical Context Egalitarianism Egalitarianism is the idea that people should be equal in important respects. This article explains its meanings, variants, history, debates, and practical implications.

Empedocles: philosopher of the four elements and the forces of Love and Strife Empedocles Empedocles, a 5th-century BCE thinker from Agrigentum, proposed the four classical elements and the twin powers Love and Strife, composed philosophical poetry, and influenced later…

Empiricism: the philosophical doctrine that knowledge derives from experience Empiricism Empiricism is the epistemological view that sense experience is the primary source of knowledge. This article outlines its core claims, history, methods, influence, and common obje…

Endoxa: Aristotle’s notion of reputable or commonly held opinions Endoxa Endoxa denotes opinions accepted by many and by reputable thinkers in Aristotle’s writings; it underpins dialectical argument, informs presumptions of common belief, and contrasts…

Enemy: adversary, threat, and concept of enmity Enemy An enemy is an individual or group regarded as an adversary or threat. This article explains types, historical and cultural roles, legal meanings in war, religious uses, and approa…

Enlightenment (intellectual movement and spiritual attainment) Enlightenment Enlightenment refers to an intellectual movement emphasizing reason and progress and to religious or spiritual experiences of insight, liberation, or awakening across many traditio…

Epictetus: Life, Teachings, and Enduring Influence of the Stoic Teacher Epictetus Epictetus (c. 55–135 AD) was a Greek Stoic philosopher whose practical ethics—centered on the distinction between what we can and cannot control—were recorded by his pupil Arrian.

Epicureanism: the philosophy of pleasure, tranquility, and atomism Epicureanism Epicureanism is an ancient Hellenistic school founded by Epicurus emphasizing absence of pain, simple pleasures, friendship, materialism and freedom from superstition.

Epicurus: Greek philosopher and founder of Epicureanism Epicurus Epicurus (341–270 BC) was an ancient Greek philosopher who founded Epicureanism, taught simple pleasures, friendship, atomism-based physics, and argued that death and divine punish…

Epistemology: the study of knowledge, justification, and belief Epistemology Epistemology is the branch of philosophy that examines the nature, sources, limits, and justification of knowledge and belief, and its role in inquiry and social life.

Epistle to Philemon: Overview, Themes, and Historical Context Epistle to Philemon A concise introduction to the Epistle to Philemon: authorship, date, contents, principal themes (forgiveness, reconciliation, social relations), and its reception in Christian trad…

Epistle to the Philippians A concise guide to the New Testament letter Paul wrote to the Christian community in Philippi: authorship, context, structure, major themes (joy, humility, Christology) and its las…

Equality Overview of equality as a concept in mathematics, law and society: definitions, historical background, major types (opportunity, racial, gender, social), distinctions (equity, fair…

Equivocation (informal fallacy of ambiguity) Equivocation Equivocation is an informal logical fallacy that exploits a word's multiple meanings to draw an invalid conclusion. This article explains how it works, gives examples, and shows ho…

Esotericism: Concepts, History, Practices, and Cultural Impact Esotericism Esotericism refers to teachings and practices claiming hidden or specialized knowledge for a restricted group; it spans mystical, occult, and symbolic traditions and has influenced…

Eternity: meaning, philosophical and religious perspectives Eternity Eternity is the idea of time without beginning or end. This article explains its meanings in philosophy, theology, science and culture, and distinguishes related terms like timeles…

Ethical tradition: social customs that shape ideas of right and wrong Ethical tradition A customary set of moral norms shared across a community, transmitted across generations and distinct from formal law or philosophical ethics.

Ethics: an introduction to moral philosophy, branches, and applications Ethics Overview of ethics (moral philosophy): central questions, main branches (normative, meta-, applied), historical development, practical uses, and distinctions like moral vs legal no…

Etienne Vermeersch (1934–2019) Etienne Vermeersch Belgian philosopher, public intellectual and skeptic who shaped debates on secularism, bioethics and science; former Jesuit turned atheist, long-time Ghent University academic and…

Eugene Thomas Long — American Philosopher of Religion (1935–2020) Eugene Thomas Long Eugene Thomas Long (1935–2020) was an American philosopher of religion known for comparative studies of Jaspers, Bultmann, Macquarrie and a century-wide survey of Western philosoph…

Eugenics: history, ideas, practices and modern relevance Eugenics Survey of eugenics: its origins, core concepts (positive and negative), historical policies and abuses, scientific critiques, and its relation to modern genetics and reproductive t…

Eurocentrism: concept, history, critiques, and global influence Eurocentrism Eurocentrism centers European experiences and categories in narratives about history, culture, and knowledge. This article outlines its forms, origins, manifestations, criticisms,…

Existential crisis A period of deep doubt or anxiety about life’s meaning, mortality, and personal purpose; causes, signs, history, and ways people cope and find direction.