The Collaborative International Dictionary
Self-evidence \Self`-ev"i*dence\, n.
The quality or state of being self-evident.
--Locke.
Wiktionary
n. The quality of being self-evident.
Wikipedia
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:
- ''A finite whole is greater than, or equal to, any of its parts
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).
Usage examples of "self-evidence".
I will take two criteria which have been suggested, namely, (1) self-evidence, (2) mutual coherence.
If this theory is to be logically tenable, self-evidence must not consist merely in the fact that we believe a proposition.
If, for example, two propositions p and q were self-evident, and it were also self-evident that p and q could not both be true, that would condemn self-evidence as a guarantee of truth.
Again, self-evidence must not be the same thing as the absence of doubt or the presence of complete certainty.
If self-evidence is alleged as a ground of belief, that implies that doubt has crept in, and that our self-evident proposition has not wholly resisted the assaults of scepticism.
Therefore, if self-evidence is a guarantee of truth, our ancestors must have been mistaken in thinking their beliefs about the Antipodes self-evident.
It would seem, therefore, that self-evidence is useless as a practical criterion for insuring truth.
But I do wish to suggest that the feeling of self-evidence in mathematical propositions has to do with the fact that they are concerned with the meanings of symbols, not with properties of the world such as external observation might reveal.
Their self-evidence, if this is so, lies merely in the fact that they represent our decision as to the use of words, not a property of physical objects.
For such reasons, no form of self-evidence seems to afford an absolute criterion of truth.
As an initial guarantee, therefore, neither self-evidence nor subjective certainty can be accepted as adequate.