First Principle

A first principle is a foundational proposition or assumption that cannot be deduced from any other proposition. In philosophy and science, first principles form the bedrock of reasoning — the irreducible truths from which all other knowledge is derived. Aristotle defined them as "the first basis from which a thing is known."

"In every systematic inquiry where there are first principles, or causes, or elements, knowledge and science result from acquiring knowledge of these." — Aristotle

Precedence in Law

Legal precedence — the principle that prior judicial decisions bind future cases with similar facts — forms the backbone of common law systems. Stare decisis, "to stand by things decided," ensures continuity in the law. Yet precedent is not absolute: courts may distinguish, limit, or overturn prior decisions when circumstances demand evolution.

The doctrine creates a hierarchy of authority: Supreme Court decisions bind all lower courts, appellate decisions bind trial courts, and lateral courts exercise persuasive but not binding authority.

Priority of Being

In metaphysics, priority of being addresses the question of what exists first or most fundamentally. Aristotle distinguished several kinds of priority: priority in time, in nature, in knowledge, and in definition. An entity is prior in nature if it can exist without another but not vice versa — substance is prior to accident, form to matter.

"The question which was raised of old and is raised now and always, and is always the subject of doubt — what is being?" — Aristotle, Metaphysics

First Mover Problem

The First Mover argument posits that all motion must originate from an unmoved mover — something that causes change without itself being changed. Aristotle's argument from Physics and Metaphysics was later adapted by Thomas Aquinas as the First Way in his Five Proofs of God's existence.

In game theory and economics, the "first mover advantage" describes the competitive edge gained by the initial significant occupant of a market segment. This advantage can include technological leadership, preemption of scarce assets, and switching costs imposed on later entrants.

Axiom and Foundation

An axiom is a statement taken to be true without proof, serving as a starting point for deductive reasoning and further arguments. In Euclid's Elements, five postulates formed the foundation of all geometric knowledge for over two millennia. The parallel postulate's independence led to the discovery of non-Euclidean geometries, demonstrating that even "first" assumptions can be questioned.

"A point is that which has no part. A line is breadthless length." — Euclid, Elements, Book I

Priority in Korean Thought

In Korean culture, 먼저 (meonjeo) carries weight beyond simple temporal ordering. The concept of going first — whether in yielding to elders (어른 먼저), in taking initiative (먼저 다가가다, "to approach first"), or in sacrifice — reflects deep Confucian values of social hierarchy and moral priority.

The phrase 먼저 가다 ("to go first") carries a euphemistic weight: it means to die before someone else, particularly a parent outliving a child. Priority, in this framing, is inseparable from loss.