Karl Popper on Tolerance and Intolerance

"Let us be clear: we are not criticizing practical tolerance, which is exercised towards individuals, but rather theoretical tolerance, which claims to be applied to ideas and grants all ideas the same rights. This would logically imply a radical skepticism. We cannot help noticing that, like all propagandists, the apostles of tolerance, truth to tell, are very often the most intolerant of men. This is what has in fact happened, and it is strangely ironical : those who wished to overthrow all dogma have created for their own use, we will not say a new dogma, but a caricature of dogma, which they have succeeded in imposing on the western world in general; in this way there have been established, under the pretext of "freedom of thought," the most chimerical beliefs that have ever been seen at any time, under the form of these different idols, of which we have just singled out some of the more important." René Guénon