ethics noun Moral principles that govern a person's behavior, or the branch of philosophy studying right and wrong. The board reviewed the company's ethics policy after the scandal came to light. + metaphysics noun The branch of philosophy that examines the fundamental nature of reality, existence, and being. Her thesis explored questions of metaphysics, such as what it means for something to exist. + epistemology noun The branch of philosophy concerned with the nature, sources, and limits of human knowledge. Epistemology asks how we can distinguish genuine knowledge from mere belief or opinion. + logic noun The systematic study of valid reasoning, or a coherent, sensible way of thinking about something. By his logic, spending more now would save money in the long run. + aesthetics noun The branch of philosophy concerned with the nature of beauty and artistic taste. The professor's course on aesthetics examined why we find certain artworks beautiful. + ontology noun The branch of philosophy that studies the nature of being, existence, and reality. Her dissertation in ontology asked what it truly means for something abstract, like a number, to exist. + empiricism noun The theory that knowledge comes mainly from sensory experience and observation rather than reasoning alone. Empiricism shaped early modern science by insisting that claims be tested through observation. + rationalism noun The philosophical view that reason, rather than experience or faith, is the primary source of knowledge and truth. Descartes is often considered a founder of rationalism because he trusted logical reasoning above the senses. + existentialism noun A philosophical movement holding that individuals must create their own meaning and purpose in an indifferent universe. Her philosophy class spent a full month studying existentialism through the works of Sartre and Camus. + nihilism noun The belief that life has no inherent meaning or purpose, and that moral truths do not exist. The novel's narrator sinks into nihilism after witnessing the horrors of war. + dualism noun A belief or theory that a subject consists of two fundamentally different or opposing parts, such as mind and body. The philosopher's dualism treated the mind as entirely separate from the physical brain. + monism noun The philosophical view that reality is fundamentally made of a single substance or principle, rather than two or more distinct kinds. The philosopher argued for monism, claiming that mind and matter are ultimately one substance. + determinism noun The philosophical view that all events are caused entirely by prior events, not free will. Strict determinism suggests that every choice we make was already inevitable. + free will noun The power to make choices that are not determined by fate, God, or prior causes. Philosophers have long debated whether humans truly have free will or only the illusion of it. + virtue noun A quality of high moral standing, such as honesty or courage, considered good or admirable. Patience is a virtue he learned slowly, through years of raising four children. + morality noun Principles and beliefs concerning what is right and wrong behavior, and the degree to which actions conform to those standards. The novel raises difficult questions about morality during a brutal war. + dialectic noun A method of examining ideas through structured argument between opposing viewpoints to reach a truth. Their dialectic moved from thesis to counterargument until a shared conclusion emerged. + syllogism noun A form of logical reasoning in which a conclusion is drawn from two given premises. The classic syllogism states: all men are mortal, Socrates is a man, so Socrates is mortal. + paradox noun A statement or situation that seems contradictory or absurd but may nonetheless be true. It's a paradox that the more choices we have, the harder it becomes to decide. + skepticism noun An attitude of doubting claims or beliefs until they are supported by sufficient evidence. The scientist approached the new theory with skepticism until the data was independently confirmed. + utilitarianism noun An ethical theory holding that the right action is the one that produces the greatest overall happiness or benefit. Utilitarianism led the committee to fund the program that would help the largest number of people. + stoicism noun The endurance of pain or hardship without complaint or visible emotion. He faced the diagnosis with a quiet stoicism that impressed everyone around him. + idealism noun The pursuit of high or noble ideals, often without full regard for what is practical or achievable. Her idealism led her to volunteer abroad instead of pursuing a higher-paying job. + materialism noun An excessive focus on acquiring money and possessions rather than spiritual or ethical values. Critics accused the holiday season of encouraging pure materialism over generosity. + consciousness noun The state of being aware of and able to think about one's own existence and surroundings. The patient slowly regained consciousness after several hours in the operating room. + cognition noun The mental process of acquiring knowledge and understanding through thought, experience, and the senses. Researchers study how sleep affects memory and other aspects of cognition. + philosopher noun A person who studies or thinks deeply about fundamental questions of knowledge, existence, and ethics. The ancient Greek philosopher Socrates taught his students by asking probing questions. + treatise noun A long, formal piece of writing that deals systematically and thoroughly with a single subject. Newton's treatise on motion and gravity changed the course of physics. + axiom noun A statement or principle widely accepted as true without needing proof. 'Honesty is the best policy' is treated almost like an axiom in many cultures. + premise noun A statement or idea assumed to be true and used as the basis for an argument or a piece of reasoning. The lawyer's entire case rested on the premise that the contract had never been signed. +