The Differences between Modernism and Post modernism

(According to C. Hugh Holman and William Harmon)

The fundamental philosophical assumptions of modernism, its tendency toward historical discontinuity, alienation, a social individualism, solipsism (a philosophical perspective that holds that one can only truly know oneself and that all other experiences are potentially false since they are filtered through the senses), and existentialism (a philosophy which claims that the individual must make decisions concerning right and wrong for him/herself without access to universal truths) continue to permeate contemporary writing, perhaps in a heightened sense. But the tendency of the modernist to construct intricate forms, to interweave symbols elaborately, to create works of art that, however much they oppose some established present order, create within themselves an ordered universe, have given way since the 1960s to a denial of order, to the presentation of highly fragmented universes in the created world of art, and to critical theories that are a form of phenomenology (a highly subjective contemporary philosophy which argues that the meaning of an object-a concept separate from its existence-is inherently related to the consciousness of the person perceiving it).

Many prominent works by authors from both periods engage in themes that relate to these philosophies indirectly. Furthermore, many of the critics responsible for the development of postmodernist theory (for example, Jacques Lacan, the members of the Frankfurt School, Michel Foucault, Roland Barthes, Jacques Derrida) have either been academically trained in philosophy themselves or substantially used the works of philosophers such as Friedrich Nietzsche, Karl Marx, Martin Heidegger, or G.W.F.Hegel as the basis for their own thoughts.

Source:

Postmodernism by Maus, Derek C, 2001