Michel Foucault (French: [miʃɛl fuko]; born Paul-Michel Foucault) (15 October 1926 – 25 June 1984) was a French philosopher, historian of ideas, social theorist, philologist and literary critic. His theories addressed the relationship between power and knowledge.
Foucault's colleague Pierre Bourdieu
summarised the philosopher's thought as "a long exploration of
transgression, of going beyond social limits, always inseparably linked
to knowledge and power."
Philosopher Philip Stokes of the University of Reading
noted that overall, Foucault's work was "dark and pessimistic", but
that it did leave some room for optimism, in that it illustrates how the
discipline of philosophy can be used to highlight areas of domination.
In doing so, Stokes claimed, we are able to understand how we are being
dominated and strive to build social structures that minimize this risk
of domination. In all of this development there had to be close attention to detail; it is the detail which eventually individualises people.
--Taken from http://en.wikipedia.org/wiki/Michel_Foucault
For a more detailed introduction go to Stanford Encyclopedia of Philosophy --http://plato.stanford.edu/entries/foucault/