The concept of toleration includes a whole range of meanings: forbearing, putting up with, permitting,accepting, recognizing. Consequently, its value is uncertain: although intolerance is generally regarded as bad and wrong and a tolerant society is generally seen as desirable, as one characterized by openness, understanding, and respect for diversity, sometimes toleration is considered as a form of weakness, questionable complacency, and indulgence, or is equated to indifference. Broadly speaking, toleration is wrongif it permits injustice; it is a necessary evil if it means acquiescing in error; it is a virtue if it promotes mutual respect and social cooperation and allows people to deal with conflicts peacefully. Depending therefore on their general view of tolerance, some people argue that the scope of toleration should be restricted, others that it should be widened, while yet others maintain that contemporary theory and society ought to leave toleration behind and to move on to equal rights, anti-discrimination, and multiculturalism.

Given that the concept of toleration allows for such divergent conceptions, it would seem reasonable for a theoretical work on toleration to begin by mapping out the concept and takingsides between the various conceptions. Yet I have not approached the subject in this way. I have taken instead what I would call a pragmatic perspective: I have begun exploring the questions which are usually regarded as relevant to toleration, and asked which ones raise genuine problems of toleration in our world.