For Habermas, the function of public debate is not to find a reasonable common ground. Rather, the public sphere ‘is a warning system’, a set of ‘sensors’ that detect the new needs floating underneath the surface of a supposed political consensus. And if we worry too much about civility and the reasonable middle, we risk limiting the ability of the public sphere to detect new political claims. To get those claims on the agenda in the first place often requires uncivil and confrontational political tactics.