Solipsists

Part of speech: noun

Definitions

1. A person who believes that only their own mind is certain to exist, often dismissing the external world as an illusion
2. An individual who maintains that knowledge of anything outside one's own mind is uncertain, leading to profound skepticism about reality itself
3. Someone adhering to the philosophical viewpoint that only their own consciousness is sure, questioning the existence of other minds or the external universe

Etymology: The word is a plural, so the core story belongs to "solipsist," the person who holds the view. That view, solipsism, is a philosophical position that only one's own mind can be known for certain, and the name for it is a recent coinage built from Latin "solus" ("alone") and "ipse" ("self"), with the "-ism" suffix added to form the doctrine. The solipsist is the person who adheres to it. The ending "-ist" has a long pedigree. It passed from Ancient Greek "-istēs," which formed agent nouns for people who practise or follow something, into Latin as "-ista," then through Old French "-iste" into Middle English as "-ist." English speakers then attached it freely to new bases, so "solipsist" was formed in English from "solipsism" plus "-ist." Plurals such as "solipsists" simply mean more than one such person. The "-s" is the ordinary English plural ending, so no further history attaches to it.