Plato once described the philosopher Diogenes of Sinope as ‘a Socrates gone mad!’ It’s a good comparison. Like Socrates, Diogenes gave the bird to respectable society. He undermined status and manners in the 4th century BCE with his bottomless reserve of shamelessness and irreverence, opting to live on the streets like a stray dog. But, of course, there was a method to his madness. In this short video by TED-Ed, the Irish philosopher William D Desmond explains how Diogenes lived an authentic and ascetic life in accordance with nature, and how in doing so he founded the philosophy of cynicism – an iconoclastic tradition that continues to illuminate and infuriate today.