The truth is what is true. It may be everything that is true (reality) or just a part of it (a fact). It may also be a statement that is true: a truth. Things or statements that are not true are untrue or false. True things exist (or have existed); false things do not (or never have).
Aristotle said: "To say of what is that it is not, or of what is not that it is, is false, while to say of what is that it is, and of what is not that it is not, is true." However, a statement may be about how things once were; this would be a true statement if it is clear that it is not a statement about how things are now. Most often, the tense of the verb will indicate this, but there may be other ways in which the statement is qualified: for example, by saying when the statement was true.
Truth is a noun, and the corresponding adjective is true. The word true also functions as a noun, a verb and an adverb. The English word truth is from Old English tríewþ, tréowþ, trýwþ, Middle English trewþe.
Most of the discussion on truth is about one of two things:
- How to find out whether a statement (a proposition or claim) is true
- How to find the truth when presented with a particular question or problem
Many philosophers have given opinions on these issues.
- It is a truth (true) that a dog is an animal. It is untrue (or false) that a dog is a plant.
- It is a truth that dodos were found on Mauritius (although not throughout the past). It is not true that dodos exist.
- It has never been true that unicorns exist, so it has always been true that unicorns do not exist.
In Other words change
Something untrue is false. A half truth is something true mixed with something false, or something partly true with key information omitted.
If the things one says are true, then they are speaking the truth, or speaking truly. Saying something that is untrue can be called a lie, if the person who is saying it knows it is untrue. A person who says something untrue is often called a "liar".
True and false in logic and philosophy change
- What is truth? Pontius Pilate (John, 18.38)
Aristotle was the first to put logic into a formal framework. His version is called propositional logic (see also syllogism and deductive reasoning). Other forms of logic use types of mathematics (mathematical logic) or symbols. Boolean algebra is about things being true and false.
Philosophers argue over what makes up truth and how to define and identify truth.