I’ll leave aside for the moment the larger conversation one could develop around Hadot, Foucault, and Sloterdijk, because doing justice to such a dialogue would require a whole new project unto itself. Instead, I’ll just mark simply—and inadequately—that the nexus of this conversation, in many ways precipitated first by Foucault’s picking up in his later works of a few central themes found in Hadot, and then carried forward by Sloterdijk’s discussion of both his predecessors, centers around askēsis and its meaning. Each figure draws us back to practice in his own way.
But more specifically, in Sloterdijk’s work the image of the athlete becomes even more pronounced than in Foucault’s treatment. “The analogy between forms of sport and forms of discourse and knowledge should be taken as literally as possible,” is how Sloterdijk puts it. The connection to sports and athletics is ubiquitous in this text, where the emphasis shifts from askēsis to ascetics, to “existential acrobatics,” “general ascetology,” and “anthropotechnics.” Askēsis in this context is a gymnastic or acrobatic ability, whether in a physical or conceptual domain.
Sloterdijk suggests that general ascetology is concerned with the question, “What is the business of the practicing life, and to what end is it pursued?” And he defines anthropotechnics as a general means of “turning the power of repetition against repetition.” While these themes bare strong conceptual resemblance to those found in Hadot and Foucault, it’s difficult not to acknowledge a shift in tone with Sloterdijk. Here the text warbles, and the paragraphs move in non-linear directions. It’s not clear that his major text on the topic of asceticism, You Must Change Your Life, should even be read from start to finish, or if the text itself isn’t some gymnastics arena designed to put the reader through their paces.
To be sure, the text is primarily concerned with the power of habit and repetition, and how both play a pronounced role in shaping human perception and behavior, but it’s also a technical manual for escaping the grip of habit and automatic thinking. Here’s Sloterdijk with a representative theme of the work, “As soon as one knows that one is possessed by automated programs—affects, habits, notions—it is time for possessing-breaking measures.” The sense here is that certain practices make possible the re-shaping of one’s life and identity (i.e., the book is full of “possession-breaking measures”). “In this manner,” writes Sloterdijk, “a subject human gradually sets itself apart from the object human,” the point being that the patterns of repetition that shape identity can be taken up into awareness and redirected through the intentional deployment of regimes of training (askēsis). The object human, gripped by habit, becomes the subject human, able to act on him or herself.
I quote Sloterdijk at length to provide the reader with a sense for his concern with this topic:
No activity evades the principle of retroactive influence on the operator—and whatever reacts to earlier events also effects later ones. The act produces the actor, the reflection the reflected, the emotion the feeler, and the test of conscience the conscience itself. . . . The practicing life is not limited to a simple reproduction of actors by their actions, however. All expansions of ability circles, all increases extending to the furthest caves of artistry, take place on the basis of self-shaping through practice.
Sloterdijk gives many names to the species whose work is precisely this “self-shaping through practice,” including Homo repetitivus, Homo artista, and Homo immunologicus. This human-in-training is a student of self-disciplines, and an athlete in pursuit of mechané (cunning), anthropotechnics (the practicing of self-forming), and the bios theoretikos (the contemplative life). This practitioner is engaged in a “philosophical multisport” in “the exercise of existence.” For Sloterdijk, the pursuit of these “ability systems” forms the basis of a somatic idealism and an intellectual athleticism, an integration of the deliverances of practice.
Hadot, Foucault, and Sloterdijk all deploy askēsis and the notion of ascetic practices in their work. In each case, askēsis is something like a fundamental requirement for living a philosophical life, present in all schools of philosophy when viewed in the right way, and though diverse in deployment in execution, share in the theme of transformation of the person in the direction emphasized by a school’s way of life, by its existential commitments, values, and beliefs. This is all true enough of philosophy, but askēsis is not limited to philosophy alone. It’s also central to Christian monastic practice (and, to be sure, other spiritual and religious schools I do not treat here), as well as to aesthetic disciplines, like art, poetry, and literature. I turn next to these disciplines.
 I’m thinking here of the 1980–1984 lecture series at the Collège de France, which includes the English language publications of Subjectivity and Truth, The Hermeneutics of the Subject, The Government of Self and Others, and The Courage of Truth.
 Sloterdijk, You Must Change Your Life, 155.
 Ibid., 336–337.
 Ibid., 155.
 Ibid., 196.
 Ibid., 197.
 Ibid., 320.
 Sloterdijk, You Must Change Your Life, 10.
 Ibid., 47, 170.
 Ibid., 154.