Postmodernism emerged in the late 1970s to capture the changed character of the sciences in the twentieth century, which called into question the idea that the organized pursuit of knowledge has a unique and natural course of development that can provide the basis for the general improvement of humanity, typically in the form of rational statecraft. This “modernist” ideal had gone under a variety of names, from positivism in philosophical circles to simply progress in more popular ones. However, far from denying the fundamental importance of knowledge, postmodernists hold that knowledge is constitutive of social and individual identity. (See knowledge society and social constructivism) Instead, what they deny is that knowledge functions in some situation-transcendent capacity as a goal or regulative ideal in terms of which progress may be measured. In this respect, postmodernism is a revolt against the normativity of knowledge. Michel Foucault's stress on the embodied and self-disciplining character of knowledge is indicative of this position. Generally speaking, social epistemology attempts to reconstruct knowledge's normativity, given the features of our epistemic predicament that Jean-François Lyotard originally called the “postmodern condition”.

The term “Enlightenment” is often used for the tendency in the history of Western thought that postmodernism is said to oppose, if not undermine. However, principled opponents of postmodernism such as Jürgen Habermas generally mean by the term something rather different from the movement's eighteenth-century originators, such as Voltaire, Diderot, Hume and Kant.