Plato called Diogenes „a Socrates gone mad“. Why mad? Because the thought and action of this Cynic philosopher, Diogenes of Sinope, appeared provocative to him, being unacceptably radical and overturning the normal order of things? More „correct diagnoses“ may, however, be forthcoming, with interpretation depending on who feels affected, offended, shocked or fascinated by Diogenes’ provocations. This essay does not aim to diagnose Diogenes’ state of health, nor it does not deal with the issue of insanity at all. Instead, it follows Plato’s advice by treating Diogenes’ provocations and excesses in relation to Socrates. That does not mean the situation does not have its complexities, particularly because Diogenes denies Socrates’ „normality“ in various ways. Three traditional approaches are available three clues: is Diogenes the representative of a simple lifestyle, is he a philosopher of dubious quality, or is he rather a philosopher par excellence? Our inclination towards the third alternative is motivated, in particular, by an interpretation of Diogenes’ asceticism (M.-O. Goulet-Cazé) and of Socrates’ moral philosophy (G. Vlastos).