Tolerance is widely recognized as one of the foundational values of open, democratic societies. It enables diverse groups of people to coexist peacefully, fostering dialogue and mutual respect across differences. However, philosopher Karl Popper introduced a compelling and somewhat controversial idea in 1945—that unlimited tolerance could ultimately threaten tolerance itself. Today, we’ll unpack this paradox and examine why, paradoxically, true freedom sometimes requires us to set limits on what we tolerate.

Let's start by clearly understanding the concept as Popper presented it.

Karl Popper argued that unlimited tolerance toward intolerant beliefs or behaviors would inevitably lead to the collapse of a tolerant society. In other words, if a society tolerates groups who explicitly advocate intolerance—those that seek to suppress freedom, silence dissent, or discriminate against others—it risks allowing those intolerant groups to gain power. Once empowered, these groups typically dismantle the very freedoms that allowed them to grow in the first place.