A truism is a claim that is so obvious or self-evident as to be hardly worth mentioning, except as a reminder or as a rhetorical or literary device, and is the opposite of falsism.[1]
In philosophy, a sentence which asserts incomplete truth conditions for a proposition may be regarded as a truism.[2] An example of such a sentence would be "Under appropriate conditions, the sun rises." Without contextual support – a statement of what those appropriate conditions are – the sentence is true but incontestable.[3]
Lapalissades, such as "If he were not dead, he would still be alive", are considered to be truisms.
An undoubted or self-evident truth; a statement which is pliantly true; a proposition needing no proof or argument; — opposed to falsism.