There’s a fine line between the toes of a brave or stupid man. Call pro extremist Dean Potter what you will. Some people call him an A-hole. In 2006, he climbed Utah’s famous and forbidden Delicate Arch – the license plate arch – sparking outrage and forcing Patagonia, his main sponsor, to drop him from its roster. Lately Potter has focused on a more daring pursuit: highlining. Although he wears a harness in the video above, he sometimes walks on wire unleashed. He says he can catch himself with his legs or hands if he ever slips. We’ll reserve judgement. He’s alive today – probably more alive than most.