Philosophy
The Political Philosophy of Civil Society and the Public Sphere
Quick fact
Actually, the quick fact is already included above. But since it's the immediate payoff, here it is again: The German philosopher Jürgen Habermas argued that the public sphere first emerged in 18th-century European coffee houses and salons, where bourgeois men gathered to debate literature and politics, laying the groundwork for modern democratic public opinion.
Why this is interesting
You've probably seen a town square or a Facebook group where people debate big issues. But what makes that conversation matter? Sometimes it changes minds, and occasionally it even changes laws—why?