From Wikipedia

History Of Impressionism
Lecture One

The Realist and the Idealist

Realism in the visual arts and literature refers to the general attempt to depict subjects "in accordance with secular empirical rules," as they are considered to exist in third person objective reality, without embellishment or interpretation. As such, the approach inherently implies a belief that such reality is ontologically independent of man's conceptual schemes, linguistic practices and beliefs, and thus can be known (or knowable) to the artist, who can in turn represent this 'reality' faithfully. As Ian Watt states, modern realism "begins from the position that truth can be discovered by the individual through the senses" and as such "it has its origins in Descartes and Locke, and received its first full formulation by Thomas Reid in the middle of the eighteenth century."

Realism often refers more specifically to the artistic movement, which began in France in the 1850s. These realists positioned themselves against romanticism, a genre dominating French literature and artwork in the late 18th and early 19th centuries. Purporting to be undistorted by personal bias, Realism believed in the ideology of objective reality and revolted against the exaggerated emotionalism of the romantic movement. Truth and accuracy became the goals of many Realists. Many paintings which sprung up during the time of realism depicted people at work, as during the 19th century there were many open work places due to the Industrial Revolution and Commercial Revolutions. The popularity of such 'realistic' works grew with the introduction of photography — a new visual source that created a desire for people to produce representations which look “objectively real.”

The term is also used to refer to works of art which, in revealing a truth, may emphasize the ugly or sordid, such as works of social realism, regionalism or Kitchen sink realism.

From Wikipedia

Idealism is the philosophical theory which maintains that the ultimate nature of reality is based on the mind or ideas. In the philosophy of perception, idealism is contrasted with realism, in which the external world is said to have an apparent absolute existence. Epistemological idealists (such as Kant) claim that the only things which can be directly known for certain are just ideas (abstraction). In literature, idealism means the thoughts or the ideas of the writer.

In the philosophy of mind, idealism is the opposite of materialism, in which the ultimate nature of reality is based on physical substances. Idealism and materialism are both theories of monism as opposed to dualism and pluralism. Idealism sometimes refers to a tradition in thought that represents things of a perfect form, as in the fields of ethics, morality, aesthetics, and value. In this way, it represents a human perfect being or circumstance.

Idealism is a philosophical movement in Western thought, and names a number of philosophical positions with sometimes quite different tendencies and implications in politics and ethics; for instance, at least in popular culture, philosophical idealism is associated with Plato and the school of platonism.