Both Derrida and Foucault are concerned about the way power often relegates the powerless, their voices and their stories, to the sideline of history. Both thinkers attempt to bring these voices to the center chiefly through a process of undermining the claims of power. Foucault, on the other hand, shows through his genealogical method that institutional power is the ground of moral and cognitive determinations. Meynell recognizes, at least, the moral value of the efforts of these two thinkers, but he finds Derrida ultimately incoherent and Foucault far too despairing. While power is potentially abusive, it is not intrinsically abusive.
Social living is conditioned by power.
The issue is the use of power, a use which can only be determined if one has a ground upon which to base a distinction between good use of power and bad use. Neither thinker produces such a ground. In fact, they claim that such a ground is impossible. However, generalized empirical method provides such a ground. The use of power then becomes critical insofar as that power, institutional power, facilitates the cognitive authenticity of the subjects of that power.