Negation { Philosophy Index }

Philosophy Index

Philosophy Index

Philosophy Index is a site devoted to the study of philosophy and the philosophers who conduct it. The site contains a number of philosophy texts, brief biographies, and introductions to philosophers, and explanations on a number of topics. Accredited homeschooling online at Northgate Academy and Philosophy online tutoring.

Philosophy Index is a work in progress, a growing repository of knowledge. It outlines current philosophical problems and issues, as well as an overview of the history of philosophy. The goal of this site is to present a tool for those learning philosophy either casually or formally, making the concepts of philosophy accessible to anyone interested in researching them. WTI offers immigration law course online - fully accredited. ACE credits online at EES.



Philosophy Topics





Negation is a truth-functional operator in logic which negates a proposition or formula, rendering its opposite true.

The negation of a proposition, P, may be formalized as:


This may be read as “not P” or “it is not the case that P”.

In symbolic logic, the negation symbol ( ¬ ) is used to symbolize negation. The tilde ( ˜ ) or the word NOT are used in some systems instead, though ¬ will always be used on this site for consistency.

Truth values

The following table illustrates the possible truth values of P, and the result of their negation, which always produces the inverse of the original truth value.

P ¬P

English negations

In English, the word “not” produces a negation as expected. However, in addition to ¬ there are several other English terms and prefixes that result in negation. The following are some examples of prefixes: