In the interest of harmony, an individual should cultivate tolerance of beliefs different from their own. While one may go beyond tolerance to cultivate curiosity or appreciation, the virtue of tolerance serves as the minimal moral demand. However, tolerance alone does not provide any framework for resolving conflicts between belief systems. When a belief cannot live and let live with another belief, tolerance alone does not tell us what to do.
In his later work on justice, John Rawls stresses that a liberal society must ultimately maintain a pluralist stance about good and acceptable beliefs. Individuals must be free to define and pursue good as they understand it as long as they can do so without causing harm to others. A pluralist must be tolerant, but pluralism also provides a standard for resolving conflicts of tolerance.
A pluralist society cannot support beliefs that do not themselves admit pluralism. Otherwise, one highly intolerant belief system can drive out all other beliefs, and pluralism collapses into monism. Karl Popper refers to this dynamic as the Paradox of Tolerance. Intolerant beliefs exceed the bounds of tolerance because they cannot coexist with other beliefs. While Popper’s Paradox has intuitive appeal, the normative proposition does not follow from the definition of tolerance alone. An additional value is needed to supply the moral judgment that Popper’s paradox endorses.
Pluralism locates tolerance in a framework for judgments about the bounds of acceptable beliefs. Where two beliefs are in conflict, pluralism requires adherents to practice tolerance for one another. A pluralist community should generally discourage overly rigid belief systems that render tolerance impossible. Where such beliefs arise organically, a society must resist accommodating them in order to preserve pluralism. Otherwise intolerant beliefs will drive more tolerant beliefs to the margins, and pluralism will collapse.