POSTMODERNISM

Historical period
Postmodernism is a philosophic and literary movement developed during the Sixties.

Tenets
It does no longer believe in the concept of truth
It puts the question of authority into doubt
It does no longer believe in the concept of centre as it generally happened in all the previous generation.

If Modernism (which covers the first three decades of the 20th century) was still looking for a centre (point of reference) and put the question and the research on art at the centre, Postmodernism questions all that and comes to the conclusion that there is no longer a single centre because saying that there is no absolute truth also implies that there is no meaning.
There is no longer one centre but a lot of centres and therefore meaning is always differed: there is a continuous slipping of the meaning because meaning is never stable. This concept is connected to the relationship between:

1. Signifier: a sign's physical form (such as a sound, printed word, or image) as distinct from its meaning.
2. Signified: the meaning or idea expressed by a sign, as distinct from the physical form in which it is expressed.

The position of the reader is the best one because it is the reader (he/she) that makes the sense because he gives one of the possible meanings to what he/she is reading.

A perfect example of Postmodernism is Oranges Are Not the Only Fruit which relies on a restructuring of the Bible structure in a new context. Another example is David Lodge's novel Nice Work.