Self-contradiction or self-contradictory can refer to:
The Berry paradox is a self-referential paradox arising from an expression like "The smallest positive integer not definable in under sixty letters".
In logic, the law of non-contradiction (LNC) states that contradictory propositions cannot both be true in the same sense at the same time, e. g. the two propositions "p is the case" and "p is not the case" are mutually exclusive. Formally, this is expressed as the tautology ¬(p ∧ ¬p). The law is not to be confused with the law of excluded middle which states that at least one, "p is the case" or "p is not the case", holds.
In philosophy and logic, the classical liar paradox or liar's paradox or antinomy of the liar is the statement of a liar that they are lying: for instance, declaring that "I am lying". If the liar is indeed lying, then the liar is telling the truth, which means the liar just lied. In "this sentence is a lie" the paradox is strengthened in order to make it amenable to more rigorous logical analysis. It is still generally called the "liar paradox" although abstraction is made precisely from the liar making the statement. Trying to assign to this statement, the strengthened liar, a classical binary truth value leads to a contradiction.
An oxymoron is a figure of speech that juxtaposes concepts with opposite meanings within a word or in a phrase that is a self-contradiction. As a rhetorical device, an oxymoron illustrates a point to communicate and reveal a paradox. A general meaning of "contradiction in terms" is recorded by the 1902 edition of the Oxford English Dictionary.
Omnipotence is the quality of having unlimited power. Monotheistic religions generally attribute omnipotence only to the deity of their faith. In the monotheistic religious philosophy of Abrahamic religions, omnipotence is often listed as one of God's characteristics, along with omniscience, omnipresence, and omnibenevolence. The presence of all these properties in a single entity has given rise to considerable theological debate, prominently including the problem of evil, the question of why such a deity would permit the existence of evil. It is accepted in philosophy and science that omnipotence can never be effectively understood.
A paradox is a logically self-contradictory statement or a statement that runs contrary to one's expectation. It is a statement that, despite apparently valid reasoning from true or apparently true premises, leads to a seemingly self-contradictory or a logically unacceptable conclusion. A paradox usually involves contradictory-yet-interrelated elements that exist simultaneously and persist over time. They result in "persistent contradiction between interdependent elements" leading to a lasting "unity of opposites".
In traditional logic, a contradiction occurs when a proposition conflicts either with itself or established fact. It is often used as a tool to detect disingenuous beliefs and bias. Illustrating a general tendency in applied logic, Aristotle's law of noncontradiction states that "It is impossible that the same thing can at the same time both belong and not belong to the same object and in the same respect."
A figure of speech or rhetorical figure is a word or phrase that intentionally deviates from straightforward language use or literal meaning to produce a rhetorical or intensified effect. In the distinction between literal and figurative language, figures of speech constitute the latter. Figures of speech are traditionally classified into schemes, which vary the ordinary sequence of words, and tropes, where words carry a meaning other than what they ordinarily signify.
In epistemology, a self-evident proposition is a proposition that is known to be true by understanding its meaning without proof, and/or by ordinary human reason.
The Grelling–Nelson paradox arises from the question of whether the term "non-self-descriptive" is self-descriptive. It was formulated in 1908 by Kurt Grelling and Leonard Nelson, and is sometimes mistakenly attributed to the German philosopher and mathematician Hermann Weyl thus occasionally called Weyl's paradox or Grelling's paradox. It is closely related to several other well-known paradoxes, in particular, the barber paradox and Russell's paradox. It is an antinomy, or a semantic self-referential paradox.
The is–ought problem, as articulated by the Scottish philosopher and historian David Hume, arises when one makes claims about what ought to be that are based solely on statements about what is. Hume found that there seems to be a significant difference between positive statements and prescriptive or normative statements, and that it is not obvious how one can coherently transition from descriptive statements to prescriptive ones. Hume's law or Hume's guillotine is the thesis that an ethical or judgmental conclusion cannot be inferred from purely descriptive factual statements.
Dialetheism is the view that there are statements that are both true and false. More precisely, it is the belief that there can be a true statement whose negation is also true. Such statements are called "true contradictions", dialetheia, or nondualisms.
In classical logic, intuitionistic logic, and similar logical systems, the principle of explosion is the law according to which any statement can be proven from a contradiction. That is, from a contradiction, any proposition can be inferred; this is known as deductive explosion.
The laws of thought are fundamental axiomatic rules upon which rational discourse itself is often considered to be based. The formulation and clarification of such rules have a long tradition in the history of philosophy and logic. Generally they are taken as laws that guide and underlie everyone's thinking, thoughts, expressions, discussions, etc. However, such classical ideas are often questioned or rejected in more recent developments, such as intuitionistic logic, dialetheism and fuzzy logic.
The barbershop paradox was proposed by Lewis Carroll in a three-page essay titled "A Logical Paradox", which appeared in the July 1894 issue of Mind. The name comes from the "ornamental" short story that Carroll uses in the article to illustrate the paradox. It existed previously in several alternative forms in his writing and correspondence, not always involving a barbershop. Carroll described it as illustrating "a very real difficulty in the Theory of Hypotheticals". From the viewpoint of modern logic, it is seen not so much as a paradox than as a simple logical error. It is of interest now mainly as an episode in the development of algebraic logical methods when these were not so widely understood, although the problem continues to be discussed in relation to theories of implication and modal logic.
Aufheben ( ) or Aufhebung ( ) is a German word with several seemingly contradictory meanings, including "to lift up", "to abolish", "cancel" or "suspend", or "to sublate". The term has also been defined as "abolish", "preserve", and "transcend". In philosophy, aufheben is used by Hegel in his exposition of dialectics, and in this sense is translated mainly as "sublate".
Owing to its origin in ancient Greece and Rome, English rhetorical theory frequently employs Greek and Latin words as terms of art. This page explains commonly used rhetorical terms in alphabetical order. The brief definitions here are intended to serve as a quick reference rather than an in-depth discussion. For more information, click the terms.
A priori and a posteriori are Latin phrases used in philosophy to distinguish types of knowledge, justification, or argument by their reliance on experience. A priori knowledge is independent from any experience. Examples include mathematics, tautologies and deduction from pure reason. A posteriori knowledge depends on empirical evidence. Examples include most fields of science and aspects of personal knowledge.
In literature, the paradox is an anomalous juxtaposition of incongruous ideas for the sake of striking exposition or unexpected insight. It functions as a method of literary composition and analysis that involves examining apparently contradictory statements and drawing conclusions either to reconcile them or to explain their presence.