Philosophy

Rationality

Rationality: Reasoned Thought, Decision-Making, and Practical Use

Raven paradox

Red herring

Red herring (fallacy and literary device)

Reductio ad Hitlerum

Reductio ad Hitlerum (playing the Hitler card)

Relativism

Relativism (philosophical concept)

Relevance

Right to die

Right to Die: Concepts, Forms, Ethical Debates and Legal Safeguards

Robert Spaemann

Romantic friendship

Romantic friendship: affectionate, non-sexual close relationships

Rota Fortunae

Rules for the Direction of the Mind

Rules for the Direction of the Mind: Descartes’ Unfinished Method

Sapir-Whorf hypothesis

Sapir–Whorf hypothesis: linguistic relativity and its implications

Satyagraha

Satyagraha: Gandhi's doctrine of nonviolent resistance

Satyameva Jayate

Scholasticism

Scholasticism: medieval method of learning, argument, and synthesis

Secular humanism

Self-denial

Self-denial: meaning, forms, history, and implications

Selfishness

Selling out

Selling out: compromise of principles for profit or popularity

Seneca

Sentience

Sentimentality

Seven deadly sins

Seven Deadly Sins (Cardinal Sins in Christian Tradition)

Shamarpa

Silhak

Silhak: Korea's practical learning movement in the Joseon era

Simple living

Simple living: principles, history, and practical approaches

Skepticism

Skepticism: doubt, inquiry, and critical thinking

Socrates

Socrates: life, method, and influence

Socrates (469–399 BC) was a classical Greek philosopher known for the Socratic method, his ethical inquiries, and his lasting influence on Western thought. He left no writings; kno

Socratic method

Socratic Method: Elenchus and Questioning as a Way of Inquiry

Solipsism

Sophism

Sophism: ancient practice and modern concept of deceptive reasoning

Soul

Soul: definitions, religious beliefs, and philosophical perspectives

Overview of the soul as a concept: definitions, major religious and philosophical views, historical development, cultural roles, and distinctions from mind or consciousness.

Stoicism

Straw man

Straw man (logical fallacy)

Sublime (philosophy)

Suffering

Summa Theologica

Svecchachara

Svecchachara: will-driven conduct in Sanskrit traditions

Syllogism

Syllogism: definition, structure, history and applications

Synthesis

Tai chi chuan

Tai chi chuan (Tàijíquán): Chinese internal martial art and health practice

Tantric yoga

Tantric Yoga: Principles, Practices, and Historical Context

Tao

Tao (Dao): Central principle of Chinese philosophy and spiritual practice

Taoism

Taoism (Daoism): beliefs, history, practices, and influence

Taoism (Daoism) is a Chinese philosophical and religious tradition centered on the Tao (the Way), emphasizing harmony with nature, simplicity, wu wei, and practices from meditation

Tautology

Teleology

The end justifies the means

The principle 'the end justifies the means' in ethics and politics

The Republic

The Republic (Plato) — overview, themes, and legacy

Plato's Republic is a Socratic dialogue that examines justice, the ideal city, philosopher‑kings, the tripartite soul, education, and the theory of forms. It deeply influenced West