Definition of: idealism

(ī·dē′əl·iz′əm) noun
1. Any of several philosophical theories that there is no reality, no world of objects or “thing–in–itself” apart from a reacting mind or consciousness; that only the mental is knowable, and therefore that reality is essentially spiritual or mental: variously developed by Berkeley, Kant, Hegel.
2. In literature, the development of subject matter following an imaginative or preconceived idea of perfection instead of adhering strictly to facts: opposed to realism.
3. The quest of the ideal; the habit of forming ideals and of striving after their realization; by extension, that which is so realized; the attainment of an ideal.
4. In art, the endeavor to attain perfection by improving and uniting in one form all the best qualities to be found in different individual forms. Idealism creates in conformity with a preconceived ideal; realism restricts the imaginative faculty.