Deleuze tells Clare Parnet (near the end of "P for Professor") of his preference for "movements" over "schools." Here is what he says:
For me, there are two important things: the relationship that one can have with students means to teach them that they must be happy with their solitude. They keep saying: a little communication, we feel isolated, we're so alone, etc., and that's why they want ''schools.'' [But they] can only achieve something as a result of their solitude, so it's to teach them the benefit of their solitude, it's to reconcile them with their solitude. That was my role as a professor. And then, the second aspect is a bit the same: I wouldn't want to introduce notions that would constitute a ''school,'' l'd want to introduce notions or concepts that would make it in the everyday arena. I don't mean these would become something ordinary, but that they would become commonly accepted ideas, namely ideas that one could handle in different ways. That could only occur if I addressed this to other solitary people who will twist these notions in their own way, to use them as they need them. So all of these are notions of movements and not notions of ''schools.''
(to watch this section of L'abécédaire, skip ahead to 6:30 in the video below)
They must be happy with their solitude, he says. I must teach them the benefit of their solitude. I often wonder if my students need to learn solitary happiness. It is remarkable how uninvested so many students are in thinking even about their own interests, even about things that seem to take up a lot of their free time, things for which they actively make free time. It's as if they need to interpellated into an engagement with themselves. Into a care of themselves?