Someone once told me that Foucault recommended that everyone should have a thinker they’re always reading but never write about. When I heard that, it struck me that mine is Foucault himself. I started reading him in college, and I’ve been reading and rereading steadily ever since. When I’d gotten through most of his published works, the lecture series started coming out. I kept up with those at first, but as I started falling behind, I started teaching Foucault. Now I’m in a reading group on The Order of Things, which I somehow skipped before.
In sum, Foucault is probably in my top five for authors I’ve read most. Yet it never occurs to me to write on him. I might use him here or there — for instance, I’m planning to do something with him in The Prince of This World — but I’d never sit down to write something thematically on Foucault.
A big part of this is my perception that Foucault is a scholarly mine field. There are so many controversies over his development and the appropriate way to periodize his work that I can already anticipate people dismissing what I have to say with the scholar’s deflationary “it’s much more complicated than that.”
The same goes for another figure I’ve spent a lot of time on but never formally written on: Heidegger. There, however, it’s more a question of not having plowed through as big a proportion of the vast material available. I know that there’s probably some text or seminar — preferrably a late one, judging by the more popular secondary works in recent years — that completely changes everything and shows that I don’t know what I’m talking about.
What about you, my dear readers? Do you have any silent partners of the kind Foucault describes?
An und für sich 
If merely using a thinker here or there doesn’t count as writing on someone, what do you mean by “writing on”? Using their name in the title of a piece? Creating an essay that’s entirely framed around this other person’s thought? If this is what it means to write on someone, then it might be the case that I’ve never really written on anyone, properly speaking. That’s not true. I’ve written a lot on Simone Weil. And have recently been writing more on Anne Conway. And I’ve had to write many, many, many course papers on figures in the Christian tradition, of course. But I do feel like one of the lessons I’ve learned through the particular feminist approach I was trained in was to hone in on questions or concepts (assuming that these are distributed among a host of thinkers), rather than take on a posture of discipleship in relation to any particular thinker. I think that this has created a resistance, on my part, to the sort of “writing on” that I feel like you’re talking about here. Of course I’ve copiously sampled from (or been in extended conversations with) Deleuze, Derrida, Augustine, Aquinas, Cusa, etc, etc, etc… in countless essays. But I’ve always been super cautious never to accidentally appear in the guise of a Deleuzian, or a Derridean, or a Heideggerian. I feel like this would only serve to further the Great Man model of scholarship that has silenced or erased the voices of many others over the centuries.
The distinction between “writing on” and “using” may be a little too easy, though it seemed intuitive to me. I’d say I’ve clearly “written on” Agamben and Zizek, and I’ve “used” them weirdly rarely. By the same time, I “used” Heidegger in Awkwardness, at somewhat great length — but what made it creative wasn’t what I was saying about Heidegger (which I wanted to keep uncontroversial in order to avoid the scholarship vortex), but the context in which I was situating him. Similarly, I doubt I’ll have any groundbreaking insights into Foucault as such when I “use” him in my book, but placing him in a demonic context may count as creative.
If I’m considering the history of philosophy, there are many that I could list, most notably, Augustine, Hegel, and Marx. As for 20th c. and contemporary thinkers, Butler, Collins, Dewey, Du Bois, and Rawls would top my list of those I read quite a bit of but never write on.
How about Kotsko…