A truism is a claim that is so obvious or self-evident

Self-evidence

In epistemology , a self-evident proposition is one that is known to be true by understanding its meaning without proof....

 as to be hardly worth mentioning, except as a reminder or as a rhetoric

Rhetorical device

In rhetoric, a rhetorical device or resource of language is a technique that an author or speaker uses to convey to the listener or reader a meaning with the goal of persuading him or her towards considering a topic from a different perspective. While rhetorical devices may be used to evoke an...

al or literary device and is the opposite of falsism

Falsism

A falsism is a claim that is self-evident that is wrong as to be hardly worth mentioning, except as a reminder or as a rhetorical or literary device. It is the opposite of truism. It can also be called a fallacy....

.

In philosophy

Philosophy

Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...

, a sentence which asserts incomplete truth conditions for a proposition may be regarded as a truism. An example of such a sentence would be: "Under appropriate conditions, the sun rises." Without contextual support — a statement of what those appropriate conditions are — the sentence is true but incontestable. A statement which is true by definition ("All cats are mammals.") would also be considered a truism. This is quite similar to a tautology

Tautology

Tautology may refer to:*Tautology , using different words to say the same thing even if the repetition does not provide clarity. Tautology also means a series of self-reinforcing statements that cannot be disproved because the statements depend on the assumption that they are already...

 in which the conclusion of a statement is essentially equivalent to its premise, a statement that is "true by virtue of its logical form

Logical form

In logic, the logical form of a sentence or set of sentences is the form obtained by abstracting from the subject matter of its content terms or by regarding the content terms as mere placeholders or blanks on a form...

 alone".

The word may be used to disguise the fact that a proposition is really just an opinion, especially in rhetoric

Rhetoric

Rhetoric is the art of discourse, an art that aims to improve the facility of speakers or writers who attempt to inform, persuade, or motivate particular audiences in specific situations. As a subject of formal study and a productive civic practice, rhetoric has played a central role in the Western...

. A saying about people or an accepted truth about life in general is also a truism.

See also

• Aphorism
  Aphorism
  An aphorism is an original thought, spoken or written in a laconic and memorable form.The term was first used in the Aphorisms of Hippocrates...
  
  
• Axiom
  Axiom
  In traditional logic, an axiom or postulate is a proposition that is not proven or demonstrated but considered either to be self-evident or to define and delimit the realm of analysis. In other words, an axiom is a logical statement that is assumed to be true...
  
  
• Cliché
  Cliché
  A cliché or cliche is an expression, idea, or element of an artistic work which has been overused to the point of losing its original meaning or effect, especially when at some earlier time it was considered meaningful or novel. In phraseology, the term has taken on a more technical meaning,...
  
  
• Platitude
  Platitude
  A platitude is a trite, meaningless, biased, or prosaic statement, often presented as if it were significant and original. The word derives from plat, the French word for "flat." Whether any given statement is considered to have meaning is highly subjective, so platitude is often—but not...
  
  
• Contradiction
  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...
  
  
• Dictum
  Dictum
  In United States legal terminology, a dictum is a statement of opinion or belief considered authoritative though not binding, because of the authority of the person making it....
  
  
• Fact
  Fact
  A fact is something that has really occurred or is actually the case. The usual test for a statement of fact is verifiability, that is whether it can be shown to correspond to experience. Standard reference works are often used to check facts...
  
  

• Figure of speech
  Figure of speech
  A figure of speech is the use of a word or words diverging from its usual meaning. It can also be a special repetition, arrangement or omission of words with literal meaning, or a phrase with a specialized meaning not based on the literal meaning of the words in it, as in idiom, metaphor, simile,...
  
  
• Jacques de la Palice
  Jacques de la Palice
  Jacques de la Palice was a French nobleman and military officer. His full name and titles are Jacques II de Chabannes, Lord of La Palice, of Pacy, of Chauverothe, of Bort-le-Comte and of Héron...
  
  
• Jenny Holzer
  Jenny Holzer
  Jenny Holzer is an American conceptual artist. Holzer lives and works in Hoosick Falls, New York.-Education:...
  
  
• Maxim
• Moral
  Moral
  A moral is a message conveyed or a lesson to be learned from a story or event. The moral may be left to the hearer, reader or viewer to determine for themselves, or may be explicitly encapsulated in a maxim...
  
  
• Synthetic proposition
• Tautology
  Tautology (rhetoric)
  Tautology is an unnecessary or unessential repetition of meaning, using different and dissimilar words that effectively say the same thing...