In previous essays (1973, 1975, 1977) I have praised Derrida's contributions to philosophical dialogue and also insisted on their limitations. The considerations raised in this present essay do not lead me to a position that is less ambivalent.
Philosophy is a particular language-game. Like any other, it has its constitutive rules; or, perhaps better: its practice has certain distinctive features by means of which we recognize philosophizing and distinguish it from other linguistic activities. None of this can be set down in the form of necessary and sufficient conditions, and there always will be large areas of controversy about the paradigms themselves. Nonetheless there are philosophers, and they generally acknowledge Plato, Aristotle, Leibniz, Hume, and even some of their colleagues as also being philosophers. This acknowledgement holds even where there is philosophical disagreement - as must inevitably be the case, in view of the dialogical character of philosophical discourse.
Derrida occasionally enters into the dialogue, as do many others - poets, novelists, critics, diplomats, attorneys, cooks, barbers, and babysitters. These occasional contributions to philosophical dialogue differ in focus, in style, and in lack of self-referentiality from the works which constitute the main corpus of philosophy. Some might wish to say, as if the matter were paradoxical, that such contributions are both philosophical and not philosophical, or that they are neither philosophy nor not-philosophy. That might be as good a thing to say as anything. The practice of philosophy is complex and has many levels. Those who are acknowledged as its finest practitioners have a focus, a style, and a respect for where questions begin and end. Derrida does not share these qualities, and does not care to share them. That is no reason to ignore his work, but it is sufficient to explain why philosophers do not recognize it as a contribution to the central corpus of philosophy.