Yelin Reviews Gaus


Posted Tuesday, September 19, 1995

"The Rational, The Reasonable, and Justification" The Journal of Political Philosophy 3:3, (September 1995): 234-258, by Gerald Gaus (University of Minnesota)

Reviewed by Lewis Yelin (Brown University) (

For a political conception of justice to be justified, it must be acceptable to all reasonable persons. This is the central claim of political liberalism. Note that the claim isn't that political principles, policies, and institutions are justified if they are endorsed by all rational individuals. This isn't accidental. Political philosophers who endorse political liberalism, John Rawls foremost among them, attempt to draw a sharp distinction between reasonableness and what they take to be the altogether different concept of rationality. Practical rationality is the capacity by which agents adopt, prioritize, and pursue ends. Reasonableness is the capacity by which they recognize the independent validity of others' claims in questions of fair social cooperation. (John Rawls, Political Liberalism [New York: Columbia University Press, 1993], pp. 50; 51, 52)

In the provocative article under review, Gerald Gaus calls into question both the sharpness of this distinction and the prioritizing of the reasonable in political justification.

Gaus begins by taking up the idea of the rational, and the standards it provides for both action and belief. Gaus argues that rational action involves more than goal-directed behavior. It involves behavior which is chosen and, importantly, chosen precisely because it is based on reasons which are somehow connected with the agent's goals. (p. 236) Gaus suggests that we adopt a conception of instrumentally rational action which asserts that an agent's action is rational if the agent chooses the action because he believes for good reason that it effectively promotes his goals. (p. 237) Whether the action actually is efficacious or not is beside the point. It's her belief in the efficacy of an action, a belief held for good reason, that determines the rationality of the action. Thus "rational action presupposes a notion of rational (or justified) belief." (p. 238)

Turning to belief, Gaus maintains that we should adopt (at least) two principles of the rationality of belief. The first is the Weak Principle of Epistemic Rationality ("WER"): An agent's belief, B, is irrational if (i) she is aware of a statement C that is incompatible with B and (ii) she is aware of very strong evidence that C has a higher credibility value than B. (p. 239) The second, the Stronger Principle of Epistemic Rationality ("SER"), requires that (i) if a proposition, B, is extremely credible, (ii) if an agent accepts the evidence for B's high credibility, and (iii) if the agent's believing B would be consistent with WER, then it's irrational for the agent not to believe B. (p. 244) WER prohibits rational agents from knowingly believing less credible propositions; SER requires them to believe the most credible propositions of which they are aware.

Gaus argues that this analysis of rationality tells against the political liberal account of justification. Central to that account, he suggests, is a conception of agent-reasonableness: "[i]f a belief B is (i) reflectively embraced by a cognitively normal agent, applying her reasoning powers, acting in good faith and paying attention to the relevant information and (ii) this acceptance is stable in light of new information and criticism, then (iii) B is a reasonable belief." (p. 245) Political liberals strive for agreement on a set of beliefs which are reasonable in this way and which can provide a basis for the political justification of a conception of justice.

But a problem arises once one realizes that reasonable agents can hold irrational beliefs. This fact should trouble political liberals because it would seem to allow justification to proceed from obviously irrational beliefs. To demonstrate this, Gaus asks us to imagine Alf attempting to justify some policy to reasonable Betty by appealing to her belief B. Betty's belief in B is in violation of WER and Alf knows this. Does Alf's appeal to B justify the policy? Political liberals, Gaus argues, must say yes. Yet this seems highly dubious: according to WER, Betty shouldn't believe B. But "if she ought not believe it, how can [Alf] appeal to it in justifying the policy? It seems quite manifest that appeal to such a belief cannot justify a policy, because appeal to a premise known to be false cannot justify a conclusion." (p. 249)

This conjecture leads Gaus to reject the Sufficiency Interpretation of reasonable justification which states that "[i]f some principle, policy, or institution would be accepted by all reasonable people it is justified." (p. 249) But reasonable people can also be irrational in that they can refuse to accept the most credible belief available to them, that is, they can hold beliefs in violation of SER. This has even stronger implications for justification: a reasonable person's rejection of a belief is no bar for that belief to serve as a basis for justification so long as the rejection is in violation of SER. (pp. 251-252) Thus it would seem that reasonable acceptability isn't even a necessary condition for political justification.

The rejection of both the Sufficiency and Necessity Interpretations of reasonable justification would clearly spell defeat for political liberalism. But Gaus has a plan to resuscitate a version of the project. Since political liberalism's woes stem from the compatibility of reasonableness and irrationality, Gaus suggests that we revise our account of reasonableness to eliminate this: "Instead of deeming a belief reasonable if it is arrived at by a reasonable person, the political liberal may directly invoke standards for the reasonableness of beliefs themselves." (p. 253) If WER and SER are a part of that standard, then the problem of reasonable but irrational beliefs disappears and the Sufficiency interpretation of reasonable justification gains plausibility.

(Note: Gaus' argument here is directed against political liberals such as Charles Larmore ["Political Liberalism," Political Theory: 18, August 1990, pp. 339-360] and Joshua Cohen ["Moral Pluralism and Political Consensus," The Idea of Democracy, ed. David Copp, Jean Hampton and John Roemer (Cambridge: Cambridge University Press, 1993), pp. 270-291] who make agent-reasonableness central to justification. Other political liberals such as Rawls use a descriptively "thicker" conception of reasonableness. In Rawls' case, the distinction between agent- and belief- reasonableness collapses and the problem of irrational yet reasonable beliefs falls to the side. See his description of reasonable people as sharing in "common human reason," That is, they share "similar powers of thought and judgment: they can draw inferences, weigh evidence, and balance competing considerations." [Political Liberalism, p. 55] As I read this passage, Rawls states that reasonable people are roughly equally rational.)

"As a justificatory category," Gaus states, "the reasonable operates within the space allowed by the rational." (p. 256) In what remains of this review, I'd like to focus on the implied claim that irrational beliefs can play no role in political justification. Consider the following case which I mean to be similar to Gaus' example of Alf and Betty: Dave and Lewis are having a discussion of policies meant to reduce inflation. Dave believes R, that raising interest rates will reduce inflation. Lewis also believes this. Dave's belief is rational, based on a highly credible economic theory. Lewis' belief is irrational, based on Voodoo. R is true (all else equal). Assume that Dave believes that Lewis' belief is rationally held (he doesn't know about Lewis' belief in Voodoo economics). Can Dave appeal to Lewis' belief in justifying the raising of interest rates? In this case, the appeal would seem to pose no problems for justification. But if this is so, then the claim that irrational beliefs can play no role in justification is wrong. Now change the case so that the shared belief is that lowering interest rates will reduce inflation. This belief is false. Still, is it appropriate for Dave to appeal to this belief of Lewis' in his attempt to justify a policy of lowering interest rates? Again, this seems acceptable. This implies that the truth or falsity of a belief which is to serve as the basis for political justification isn't relevant to justification. What is relevant is the parties' beliefs about the truth or falsity of the belief.

Assuming that you found the case of Alf and Betty troubling and that you agree that the case of Dave and Lewis isn't, what makes these two cases different? The difference is that Alf appeals to a belief of Betty's that he knows she holds irrationally where Dave does no such thing to Lewis. This suggests that what's troubling in the case of Alf and Betty isn't that Betty's irrational belief is appealed to in justification, but that Alf manipulates Betty. Betty believes something she ought not. Alf knows this, but still uses this belief in his attempt to elicit agreement from Betty. If I'm correct here, what this shows is not that the rational limits the reasonable as Gaus would have it, but that we should count as a characteristic of reasonable people the fact that they would not knowingly appeal to the irrationally held beliefs of others in attempts at justification.