Second, pluralism is not just tolerance, but the active seeking of understanding across lines of difference . Tolerance is a necessary public virtue, but it does not require Christians and Muslims, Hindus, Jews, and ardent secularists to know anything about one another. Tolerance is too thin a foundation for a world of religious difference and proximity. It does nothing to remove our ignorance of one another, and leaves in place the stereotype, the half-truth, the fears that underlie old patterns of division and violence. In the world in which we live today, our ignorance of one another will be increasingly costly.