By drawing connections between Deleuze's thought and the thought of Immanuel Kant, a space is allowed to emerge for exploring the development of an ethics from Deleuze's immanentist reading of Kantian critique. This space calls for an adjustment in expectations surrounding what counts as ethics. For ethics is not merely the articulation of sets of rules or hierarchies of the good. It is also, and perhaps primarily, an attitude toward life that is habituated and cultivates a character. This character – dramatised by figures such as the Apprentice and the Russian idiot in Deleuze's early work, and expanded to include the nomad, becoming-woman and the minor in his work with Guattari – expresses a way of living Deleuze's ontology of intensive becoming. Moreover, the space created is one that could not be mapped without the comparison to Kant. The deep logic of the faculties that expresses the dynamic of powerlessness becoming power, the transcendental subject for whom a preparatory education of sensibility in culture is tantamount to the formation of a non-fascistic identity, the connection to the long tradition of critical thinking in education as paideia, and the platform on which to turn the critique back onto Deleuze, are all features of the ethics mapped out by Deleuze's work that are overlooked when the focus is exclusively on Nietzschean activity/reactivity or Spinozist expressions of worthiness. An understanding of Kant – and especially the idea of critique, the theory of faculties, and the relationship between culture and morality – is crucial for understanding the ethical stakes and promise of Deleuze's philosophy. When this starting point is taken seriously, the critical ethos implicit in much of Deleuze's thought is easy to map, from his earliest works on Nietzsche, Kant and Proust, through the development of the radical critique in Difference and Repetition, to its transformation into schizoanalysis in Capitalism and Schizophrenia, and finally to its distillation in immanence in his last works. This critical ethos expresses the mode of living an ontology of becoming through a critique of subjectivity and in so doing promotes non-rule-based ethical decision-making as a value-creating and fulfilled way of life.