Discourse analysts are often accused of two things, namely, that Discourse Analysis leads to a vicious relativism, and that it lapses into philosophical idealism.
The charge of relativism contends that since, according to Discourse Analysis, there are no ultimate foundations and so everything is discursive, discourse analysts end up in a situation where everything is equally true, right and good. This supposedly makes it impossible to defend any particular set of claims or values.
The premise of the argument is correct. Discourse Analysis claims that there is no extra-discursive truth, morals or ethics. However, the conclusion is wrong, since discourse analysts never arrive at a situation where everything is equally valid. Discourse analysts always find themselves located within a particular discourse, which necessarily provides a set of historically contingent criteria for determining what is true, right and good. Only God is capable of transcending all discursivity. We mortals are always placed within discursive frameworks that define our criteria of validity. These frameworks are constantly renegotiated through processes of disintegration, mutual exchange, or antagonistic conflict.