What remains relevant in Michel Foucault’s thought today, 100 years after his birth and over 40 years after his death? Not his controversially debated diagnoses of the ‘death of man’, the ‘disciplinary society’ or ‘biopolitics’ – this is the first thesis of this talk – but his method. It should be reconstructed – second thesis – as a mode of thinking in terms of conditions of existence. Foucault does not examine the conditions of possibility, as transcendental philosophical does, but rather analyses the conditions of our existence archaeologically and genealogically along the three dimensions of knowledge, power and subjectivity. Uncovering this alternative form of philosophising, according to the third thesis, enables us to formulate critical diagnoses of our present, rather than merely extending Foucault’s old diagnoses of his own time.