Foucault was also interested in the analysis of discourse that relied on power and knowledge relations throughout his career. For Foucault, discourse cannot be inconceivable separated from the epistemes of the historical period in which it arises. Discourse, is an instrument of constituting knowledge, together with the social practice and power relations. On the one hand, discourse is created and perpetuated by the power; on the other hand, power is produced and transmitted by discourse. As expressed by Foucault, discourses constitute the reality, what can be thought and said about the world. Discourse as defined by Foucault, is the whole of the practices that construct the objects it speaks on or creates its own truth. So, according to Foucault there is no universal reality or truth as in poststructuralist thought. He asserts that meaning, truth and morality are created through discourse.