idealism, the attitude that places special value on ideas and ideals as products of the mind, in comparison with the world as perceived through the senses. In art idealism is the tendency to represent things as aesthetic sensibility would have them rather than as they are. In ethics it implies a view of life in which the predominant forces are spiritual and the aim is perfection. In philosophy the term refers to efforts to account for all objects in nature and experience as representations of the mind and sometimes to assign to such representations a higher order of existence. It is opposed to materialism. Plato conceived a world in which eternal ideas constituted reality, of which the ordinary world of experience is a shadow. In modern times idealism has largely come to refer the source of ideas to man's consciousness, whereas in the earlier period ideas were assigned a reality outside and independent of man's existence. Nevertheless, modern idealism generally proposes suprahuman mental activity of some sort and ascribes independent reality to certain principles, such as creativity, a force for good, or an absolute truth. The subjective idealism of George Berkeley in the 18th cent. held that the apparently objective world has its existence in the consciousness of individuals. Immanuel Kant developed a critical or transcendental idealism in which the phenomenal world, constituted by the human understanding, stands opposed to a world of things-in-themselves. The post-Kantian German idealism of J. G. Fichte and Friedrich von Schelling, which culminated in the absolute or objective idealism of G. W. F. Hegel, began with a denial of the unknowable thing-in-itself, thereby enabling these philosophers to treat all reality as the creation of mind or spirit. Forms of post-Kantian idealism were developed in Germany by Arthur Schopenhauer and Hermann Lotze and in England by Samuel Coleridge; forms of post-Hegelian idealism were developed in England and France by T. H. Green, Victor Cousin, and C. B. Renouvier. More recent idealists include F. H. Bradley, Bernard Bosanquet, Josiah Royce, Benedetto Croce, and the neo-Kantians such as Ernst Cassirer and Hermann Cohen.
See J. H. Muirhead, The Platonic Tradition in Anglo-Saxon Philosophy (1931, repr. 1965); A. C. Ewing, ed., The Idealist Tradition (1957); G. A. Kelly, Idealism, Politics, and History (1969).