From a post by Fr. Dwight Longenecker
…To paraphrase G.K.Chesterton, "Tolerance is a nice word for indifference and indifference is an elegant word for ignorance." The reason for having an open mind (like the reason to have an open mouth) is eventually to close it–because it has been filled with something good.
Tolerance, on its own, is a weak virtue that eventually turns on itself with a suicidal bent. This is because the one thing tolerance cannot tolerate is intolerance, and the more tolerant a person becomes the more every little bit of intolerance becomes intolerable. So the person who puts tolerance as the highest and only virtue, finally is incapable of tolerating anyone or anything or any law that limits or defines anything because to limit or define any behavior or any sort of person is perceived as a form of intolerance.
I recently read Truth And Tolerance: Christian Belief And World Religions by then-Cardinal Ratzinger which was published in 2004. This book is highly recommended if you want to go deeper on the topic of tolerance especially on the topic of religious tolerance. This book proves once again how silly the caricature of him that was made after the publication of Dominus Iesus. Like most books of his on theology I felt the pain of normally unused synaptic muscles being strained to their utmost – but hey no pain, no gain – and this book is definitely in the category of gain.