﻿
(or law of )
The law of logic that it is not the case that (p & not-p ). Contradiction is the final logical stopping-point: if we can derive a contradiction from a set of premises, then at least one of them is false (see reductio ad absurdum ). If we ask what is so bad about contradiction, one answer is that a contradiction cannot be true (classically, if one conjunct p is true, then the other not-p is false, and vice versa, so they cannot be true together; see also negation ). Another answer is that from a contradiction anything whatsoever can be derived, which is true in classical logical systems. See dialetheia ; strict implication, paradox of.

Philosophy dictionary. . 2011.

### Look at other dictionaries:

• Principle of contradiction — In logic, the Principle of contradiction ( principium contradictionis in Latin) is the second of the so called three classic laws of thought. The oldest statement of the law is that contradictory statements cannot both at the same time be true, e …   Wikipedia

• Principle of bivalence — In logic, the semantic principle of bivalence states that every proposition takes exactly one of two truth values (e.g. truth or falsehood ). The laws of bivalence, excluded middle, and non contradiction are related, but they refer to the… …   Wikipedia

• Non-standard cosmology — Physical cosmology Universe · Big Bang …   Wikipedia

• Non-Aristotelian logic — The term non Aristotelian logic, sometimes shortened to null A, means any non classical system of logic which rejects one of Aristotle s premises (see term logic). Contents 1 History 2 Use in science fiction 3 See also 4 …   Wikipedia

• Non-Euclidean geometry — Behavior of lines with a common perpendicular in each of the three types of geometry Non Euclidean geometry is the term used to refer to two specific geometries which are, loosely speaking, obtained by negating the Euclidean parallel postulate,… …   Wikipedia

• Contradiction — In classical logic, a contradiction consists of a logical incompatibility between two or more propositions. It occurs when the propositions, taken together, yield two conclusions which form the logical, usually opposite inversions of each other.… …   Wikipedia

• Non-topological soliton — In quantum field theory, a non topological soliton (NTS) is a field configuration possessing, contrary to a topological one, a conserved Noether charge and stable against transformation into usual particles of this field for the following reason …   Wikipedia

• Harm principle — The harm principle holds that the actions of individuals should only be limited to prevent harm to other individuals. John Stuart Mill first articulated this principle in On Liberty, where he argued that the only purpose for which power can be… …   Wikipedia

• Novikov self-consistency principle — The Novikov self consistency principle, also known as the Novikov self consistency conjecture, is a principle developed by Russian physicist Igor Dmitriyevich Novikov in the mid 1980s to solve the problem of paradoxes in time travel, which is… …   Wikipedia

• Reflection principle — This article is about the reflection principles in set theory. For the reflection principle of complex analysis, see Schwarz reflection principleIn set theory, a branch of mathematics, a reflection principle says that it is possible to find sets… …   Wikipedia