It is a critical and yet uncritical in its subversion. Just like looking on how to destroy or to defeat an enemy" http://www.geocities.com/philodept/diwatao/derrida_and_saussure.htm
Different scholars and critics defined Deconstruction in their own way. Somehow with many definitions the theory became richer over the years. "It represents a complex response to a variety of theoretical and philosophical movements of the 20th century, most notably Husserlian phenomenology, Saussurean and French structuralism, and Freudian and Lacanian psychoanalysis" http://prelectur.stanford.edu/lecturers/derrida/deconstruction.html
Derrida starts with the structure, but he is not happy with the binary structure and showed that dualisms are never equivalent; but are hierarchically placed. He said one pole is privileged at the expense of the other. The centre and presence are the originally attributed qualities to the speech, which have been continuing for a long time now. Speech has been given more importance, whereas the writing has been relegated into the secondary place. He said the logocentric tradition of the western thought since Plato has made the written word as a mere representation of the spoken word. Paul De Mann is another critic who adopted the same style of criticism. It is best understood as a textual strategy. He posed a challenge to metaphysical speculation.
He argued: "Structure has always been neutralised or reduced.by giving it a centre or referring it to a point of presence, a fixed origin," Derrida (1978, p.278) and even the quantitative enlargement of adding historical experience does not help it. He started with exposing the problems of centred discourses. "Derrida argues that the "structure" determining these discourses (including "structuralist" theory itself) always presupposes a "centre" that ensures a point of origin, meaning, being, or presence. What troubles Derrida is that the centre determines a given systems structure but is itself strangely above or transcendent of such structural analysis or scrutiny" http://www.usp.nus.edu.sg/post/poldiscourse/spivak/deconstruction.html His argument is that the centre that ensures a presence. The presence, he says, is the original state and should come first, just like how the world is present around us, and it is connected to the consciousness and self-reflection and gives a meaning. This means, presence is the predicate for a text's meaning, according to Derrida.
It is accepted that Derrida had great influence on the intellectual thinking of the world. The paper he presented to John Hopkins University in 1966 changed the critical movement in United States. In this paper he uses the structure, structuralist theory while saying that there exists a centre in every structure. He argues that this is needed by the readers because it is definite that there is an existing presence. The centre is the main unity that supports the structure, which would not have contained much meaning without that centre. "if we try to undo the centring concept of 'consciousness' by asserting the disruptive counterforce of the 'unconscious' we are in danger of introducing a new centre, because we cannot choose but enter the conceptual system (conscious/unconscious) we are trying to dislodge," Selden (1985, p.144).
Deconstruction and poststructuralism have been in close terms