Those who believe in idealism. They may be divided into two distinct sections—
(1) Those who follow Plato, who taught that before creation there existed certain types or ideal models, of which ideas created objects are the visible images. Malebranche, Kant, Schelling, Hegel, etc., were of this school.
(2) Those who maintain that all phenomena are only subjective—that is, mental cognisances only within ourselves, and what we see and what we hear are only brain impressions. Of this school were Berkeley, Hume, Fichte, and many others.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894