Dans l'introduction de Therapy of desire(1994), Martha Nussbaum présente ainsi la critique qu'elle fait de l'approche que Foucault a eue des philosophies hellénistiques:
" There is one reclaiming of Hellenistic texts within philosophy -perhaps the most widely known to the general public- that seems to me, though exciting, also deeply problematic. This is Michel Foucault's appeal to the Hellenistic thinkers, in the third volume of his History of Sexuality, and in lectures given toward the end of his life, as sources for the idea that philosophy is a set of techniques du soi, practices for the formation of a certain sort of self. Certainly Foucault has brought out something very fundamental about these philosophers when he stresses the extent to which they are not just teaching lessons, but also engaging in complex practices of self-shaping. But this the philosophers have in common with religious and magical/superstitious movements of various types in their culture. Many people purveyed a biou techne, an "art of life." What is distinctive about the contribution of the philosophers is that they assert that philosophy, and not anything else, is the art we require, an art that deals in valid and sound arguments, an art that is commited to the truth. These philosophers claim that the pursuit of logical validity, intellectual coherence, and truth delivers freedom from the tyranny of custom and convention, creating a community of beings who can take charge of their own life story and their own thought. (Skepticism is in some ways an exception, as we shall see; but even Skeptics rely heavily on reason and argument, in a way other popular "arts" do not.) It is questionable whether Foucault can even admit the possibility of such a community of freedom, given his view that knowledge and argument are themselves tools of power. In any case, his work on this period, challenging though it is, fails to confront the fundamental commitment to reason that divides philosophical techniques du soi from other such techniques. Perhaps that commitment is an illusion. I believe that it is not. And I am sure that Foucault has not shown that it is. In any case, this book will take that commitment as its focus, and try to ask why it should have been thought that the philosophical use of reason is the technique by which we can be truly thinking and truly flourishing." (p.5-6)
On peut lire ce texte comme une défense, dans la tradition des Lumières, de la raison comme moyen d'émancipation réelle. En dehors de tout relativisme et de toute herméneutique du soupçon, Martha Nussbaum prend position en faveur de la valeur non seulement gnoséologique mais aussi éthique de la cohérence et du respect de la vérité. Elle tient ainsi à établir une frontière nette entre l'usage de la raison à des fins libératrices et l'usage de techniques irrationnelles, par exemple, religieuses. Il va de soi que le camp visé par Martha Nussbaum pourra juger avec condescendance ce plaidoyer en faveur de la raison qu'il taxera alors de naïf et illusoire. Mais aura-t-il raison ?