H. P. Grice, "Boethius on the multiplicity of 'esse'"

ESSE -- entia per se, see entia per alio entia rationis, Latin term for entities of reason entity Metaphysics [from Latin ens, being, thing] A term generally used interchangeably with thing or object. Joseph Owens has proposed that entity should be used to translate the Greek ousia, which is usually translated as substance, because ousia is derived from the Greek copula estin and entity is similarly derived from the Latin copula ens. Hence, this translation would maintain an important etymological relation. However, his suggestion has difficulties. While ousia can be used both independently and as “ousia of . . . ,” in English we cannot say “entity of . . .” “In consequence of this perversion of the word Being, philosophers looking about for something to supply its place, laid their hands upon the word entity, a piece of barbarous Latin, invented by the schoolmen to be used as an abstract name, in which class its grammatical form would seem to place it, but being seized by logicians in distress to stop a leak in their terminology, it has ever since been used as a concrete name.” The Collected Works of John Stuart Mill, vol. VII -- entity of reason Metaphysics, epistemology [Latin ens rationis, also called an ideal entity] In Scholastic philosophy, there are things which do not really exist, but which are apprehended by reason, that is, conceptual entities such as relations, orderings, or general notions. A relation does not exist like a substance or accident, but is a conception obtained by abstraction from a consideration of things having certain associations to each other. An entity of reason is not an actual thing, but is an object of knowledge and has its foundations in actual things. “If ‘nothing’ means something imaginary, or what they commonly call an entity of reason [ens rationis], then this is not ‘nothing’ but something real and distinctly conceived. Nevertheless, since it is merely conceived and is not actual, although it can be conceived, it cannot in any way be caused.” Descartes, The Philosophical Writings