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

Some epistemologists deny that any proposition can be self-evident. For most others, the belief that oneself is conscious is offered as an example of self-evidence. However, one's belief that someone else is conscious is not epistemically self-evident.

The following proposition is often said to be self-evident:

Also self evident is the statement that two plus two is equal to 4.

A logical argument for a self-evident conclusion would demonstrate only an ignorance of the purpose of persuasively arguing for the conclusion based on one or more premises that differ from it (see ignoratio elenchi and begging the question).

Analytic propositions

It is sometimes said that a self-evident proposition is one whose denial is self-contradictory. It is also sometimes said that an analytic proposition is one whose denial is self-contradictory. But the concepts do mean different things.