# Question: Are Tautologies Valid?

## Is tautology a fallacy?

A tautology in math (and logic) is a compound statement (premise and conclusion) that always produces truth.

No matter what the individual parts are, the result is a true statement; a tautology is always true.

The opposite of a tautology is a contradiction or a fallacy, which is “always false”..

## Is a tautology always true?

A tautology is a formula which is “always true” — that is, it is true for every assignment of truth values to its simple components. You can think of a tautology as a rule of logic. The opposite of a tautology is a contradiction, a formula which is “always false”.

## What is it called when you use 2 words that mean the same thing?

If two words are synonymous, they mean the same thing. … In addition to describing words with the same or similar meanings, you can use the adjective synonymous to describe things that are similar in a more figurative way.

## How do you know if a statement is a tautology?

If you are given any statement or argument, you can determine if it is a tautology by constructing a truth table for the statement and looking at the final column in the truth table. If all of the truth values in the final column are true, then the statement is a tautology.

## What is an example of tautology?

In grammatical terms, a tautology is when you use different words to repeat the same idea. For example, the phrase, “It was adequate enough,” is a tautology. The words adequate and enough are two words that convey the same meaning.

## What do you call a statement that is always true?

Summary: A compound statement that is always true, regardless of the truth value of the individual statements, is defined to be a tautology. We can construct a truth table to determine if a compound statement is a tautology.

## Is tautology a figure of speech?

A tautology often involves just a few words in a sentence that have the same meaning, or in which one word is part of the definition of the other word. Though tautologies are common in everyday speech and don’t diminish clarity, they should be avoided in formal writing so you don’t repeat yourself unnecessarily.

## What is the opposite of a tautology?

Tautology refers to a redundant use of language, “too many words”. The opposite of that would presumably be “not enough words”, excessive concision, terseness, insufficiency, curtness. 3. Contradiction refers to something going against something else.

## What is an example of paradox?

Here are some thought-provoking paradox examples: Save money by spending it. If I know one thing, it’s that I know nothing. This is the beginning of the end. Deep down, you’re really shallow.

Since a contradiction has to be made up by at least one false premise, it can’t be made up of premises that are all true. Therefore it can’t be invalid, so it must be a valid argument.

The standard criticism of tautologies goes like this: because of the the fact that tautologies are necessarily true, they do not tell us anything new about the world. They cannot possibly be wrong; therefore, they do not add to our knowledge. They are redundancies, and they ultimately do not need to be stated.

## Why is a tautology useless for logical argumentation?

An argument requires support for an idea where as a tautology is merely a repetition/rephrasing of an idea. If a tautology was posed as an argument it would be an invalid one because it doesn’t support the idea any further, not because it is logically incorrect.

A paradox, also known as an antinomy, 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 premises, leads to a seemingly self-contradictory or a logically unacceptable conclusion.

to assert the contrary or opposite of; deny directly and categorically. to speak contrary to the assertions of: to contradict oneself. (of an action or event) to imply a denial of: His way of life contradicts his stated principles. Obsolete. to speak or declare against; oppose.

## What is it called when someone does the opposite of what they say?

The verbal form of irony is sarcasm, which is when someone says the opposite of what he or she means or says something out of character, usually to emphasize the absurdity of something or to convey the opposite point. The other use for irony us to convey something opposite to what you’re actually saying.

## What is the most famous paradox?

Russell’s ParadoxRussell’s paradox is the most famous of the logical or set-theoretical paradoxes. Also known as the Russell-Zermelo paradox, the paradox arises within naïve set theory by considering the set of all sets that are not members of themselves.

## Can you use the same word twice in a sentence?

On occasion, an immediate repetition of a word, separated by punctuation, is appropriate for emphatic effect, for example, “I am far, far away from home.” So, the rule is, repetition of a word in a sentence that makes grammatical sense isn’t wrong, but there is actually no reason for this to occur if you put the extra …

## How can tautology be prevented?

How to Avoid Tautology. In order to avoid using tautologies, pay careful attention to the logic of what you are writing. Often beginning writers cannot see what they have written as objectively as other people and may not notice tautologies, so you have to practice reading your writing as if you were someone else.

## What do you call a person who contradicts himself?

A hypocrite. Cambridge[1] dictionary defines ‘hypocrite’ as, “someone who says that they have particular moral beliefs but behaves in a way that shows these are not sincere” An example[2] of a hypocrite is a person who says they care about the environment, but are constantly littering.

## When someone does the opposite of what they say?

“Contra-” usually means “against,” and to contradict is to go against or say the opposite of what someone else is doing or saying.