Tolerance has its arguments, both in morality and in law. It also has its sources, not only in the sense of the origins from which it springs, but also in the sense of that which actuates it and gives it life, that which encourages it and sanctions it - profoundly. Religions take part of these sources, but also take part of this reflexive aspect of ethics that puts into play the final legitimation, the ultimate justification of the norms of our public and private actions. It is with respect to this recourse to the ultimate that religion and ethics intersect without becoming one. Yet it is also in this recourse to the ultimate that one and the other greatly face the danger of temptation. This is particularly the case with religion. It is indeed not enough to simply say that it is the political use of religion that is to blame, and not religion as such, in the long and unfinished history of religious intolerance. We must trace the source of the temptation of intolerance to the very heart of the certainty of religious faith. Any belief, as soon as it defines itself in relation - a relation of any kind, whether of distance or proximity, of alterity or fusion - to an absolute, must be on guard against its own penchant for intolerance. It is not enough, in an opposite sense of the preceding warning, to rely on the critical resources borrowed from sources outside of religion: it is at that same heart of certainty of all religious faith that we must seek the reason for the conviction that it is unjust to look to impose on adherents of other religions, on agnostics and atheists, the truth as it is admitted in good faith by the community of believers of one or another religious confession.