Reflective equilibrium

Reflective equilibrium is a state of balance or coherence among a set of beliefs arrived at by a process of deliberative mutual adjustment among general principles and particular judgments. Although he did not use the term, philosopher Nelson Goodman introduced the method of reflective equilibrium as an approach to justifying the principles of inductive logic. The term 'reflective equilibrium' was coined by John Rawls and popularized in his A Theory of Justice as a method for arriving at the content of the principles of justice.

Rawls argues that human beings have a "sense of justice" which is both a source of moral judgment and moral motivation. In Rawls's theory, we begin with "considered judgments" that arise from the sense of justice. These may be judgments about general moral principles (of any level of generality) or specific moral cases. If our judgments conflict in some way, we proceed by adjusting our various beliefs until they are in "equilibrium," which is to say that they are stable, not in conflict, and provide consistent practical guidance. Rawls argues that a set of moral beliefs in ideal reflective equilibrium describes or characterizes the underlying principles of the human sense of justice.

An example of the method of reflective equilibrium may be useful. Suppose Zachary believes in the general principle of always obeying the commands in the Bible, and mistakenly thinks that these are completely encompassed by every Old Testament command. Suppose also that he thinks that it is not ethical to stone people to death merely for being Wiccan. These views may come into conflict (see Exodus 22:18, but see John 8:7). If they do, Zachary will then have several choices. He can discard his general principle in search of a better one (for example, only obeying the Ten Commandments), modify his general principle (for example, choosing a different translation of the Bible, or letting Jesus' teaching from John 8:7 "If any of you is without sin, let him be the first to cast a stone" override the Old Testament command), or change his opinions about the point in question to conform with his theory (by deciding that witches really should be killed). Whatever the decision, he has moved toward reflective equilibrium.

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