Proof (truth)

A proof is sufficient evidence or an argument for the truth of a proposition.

The concept is applied in a variety of disciplines, with both the nature of the evidence or justification and the criteria for sufficiency being area-dependent. In the area of oral and written communication such as conversation, dialog, rhetoric, etc., a proof is a persuasive perlocutionary speech act, which demonstrates the truth of a proposition. In any area of mathematics defined by its assumptions or axioms, a proof is an argument establishing a theorem of that area via accepted rules of inference starting from those axioms and other previously established theorems. The subject of logic, in particular proof theory, formalizes and studies the notion of formal proof. In the areas of epistemology and theology, the notion of justification plays approximately the role of proof, while in jurisprudence the corresponding term is evidence, with burden of proof as a concept common to both philosophy and law.

Truth

Truth is most often used to mean being in accord with fact or reality, or fidelity to an original or standard. Truth may also often be used in modern contexts to refer to an idea of "truth to self," or authenticity.

The commonly understood opposite of truth is falsehood, which, correspondingly, can also take on a logical, factual, or ethical meaning. The concept of truth is discussed and debated in several contexts, including philosophy, art, and religion. Many human activities depend upon the concept, where its nature as a concept is assumed rather than being a subject of discussion; these include most (but not all) of the sciences, law, journalism, and everyday life. Some philosophers view the concept of truth as basic, and unable to be explained in any terms that are more easily understood than the concept of truth itself. Commonly, truth is viewed as the correspondence of language or thought to an independent reality, in what is sometimes called the correspondence theory of truth.

Proof

Proof may refer to:

Law

Entertainment

Flat Earth

The flat Earth model is an archaic conception of the Earth's shape as a plane or disk. Many ancient cultures subscribed to a flat Earth cosmography, including Greece until the classical period, the Bronze Age and Iron Age civilizations of the Near East until the Hellenistic period, India until the Gupta period (early centuries AD) and China until the 17th century. That paradigm was also typically held in the aboriginal cultures of the Americas, and the notion of a flat Earth domed by the firmament in the shape of an inverted bowl was common in pre-scientific societies.

The idea of a spherical Earth appeared in Greek philosophy with Pythagoras (6th century BC), although most Pre-Socratics retained the flat Earth model. Aristotle accepted the spherical shape of the Earth on empirical grounds around 330 BC, and knowledge of the spherical Earth gradually began to spread beyond the Hellenistic world from then on.

Historical development

Ancient Near East

In early Egyptian and Mesopotamian thought the world was portrayed as a flat disk floating in the ocean. A similar model is found in the Homeric account of the 8th century BC in which "Okeanos, the personified body of water surrounding the circular surface of the Earth, is the begetter of all life and possibly of all gods." The Israelites likely had a similar cosmology, with the earth as a flat disc floating on water beneath an arced firmament separating it from the heavens.