The last 2 sections of Chapter IX of A Theory of Justice are also the last 2 sections of the whole book. In this posting I will treat them both in turn. Section 86, entitled "the good of the sense of justice" is intended to complete the argument for the view that there is a reasonable expectation that, in a well-ordered society, there would be congruence between justice and the specific conceptions of the good that are adopted by individuals. Since this argument concerning congruence was also motivated at the beginning of Chapter IX as the rationale for the whole argument of this chapter section 86 essentially completes the general purpose of the chapter. The concluding section 87 is meant not to add to this argument but, rather, to offer a general overall summary of the way in which the theory of justice as fairness has been "justified" in the book as a whole.
Section 86 opens with Rawls stating that the completion of the congruence argument basically requires an overall view of the notion of the well-ordered society. In this society the two moral powers of persons - the capacity for a sense of justice and the ability to pursue a particular conception of the good - are congruent with each other or so is the assumption and the argument of the chapter, which is completed here, is intended to show the reasons for taking this to be the case. The central reason for being concerned with the congruence between the two moral powers in the well-ordered society is that such congruence is assumed to be the basis of the stability of it. This does not require reviewing again the rationality of the selection of the principles of justice within the original position as we take for granted by this stage that this selection has been justified. The problem is, rather, "whether the regulative desire to adopt the standpoint of justice belongs to a person's own good" when we view the latter in the light of Rawls' "thin" theory of the good. When we arrive at this point we are no longer behind the veil of ignorance as the "thin" theory can be fully specified.
The justification of the view that it is rational for someone, merely following the thin theory of the good, to accept the claim of the sense of justice to be regulative of their conception of the good, is not equivalent to justification of the sense of justice to an egoist. Nor does Rawls aim to show that, in a well-ordered society, even an egoist would act from a sense of justice. Rawls is instead assuming that there does exist amongst the members of the well-ordered society a settled desire to act from the sense of justice and then raising the question of whether this desire is one that is consistent with the good of these people. This question presupposes only the "thin" theory of the good as anything wider would involve wider presuppositions. So the question concerns only those with a moral psychology that is already, at least in one of its relevant aspects, as we would ideally wish it to be.
Now this does not mean that the question has been so carefully curtailed as to be of little interest. So Rawls is not assuming for example that everyone simply does things due to motivation by pure conscientiousness. It is conceivable, even assuming that there is a settled desire to act from the sense of justice, that this settled desire is one that runs up against formidable resistance when acting upon it appears to cut against some key element of that persons' view of the good. Then the question may arise for them what to do and not be one that they simply take to have an obvious answer.
Having stated the problem in this way Rawls proceeds to describe the elements of the "grounds of congruence". The first element is that the principles of justice are public, a point he consistently stresses. Since this is so the consideration of acting in a way that does not conform to the principles of justice is one in which we think of ourselves as prepared to act as free riders upon the public good. Given that the settled disposition to act from a sense of justice is one that is given reinforcement by the publicly acknowledged justification of the principles of justice the consideration of acting in such a way is sure to have psychic cost. Not only is this the case but failure to act from the sense of justice is something whose public effect we would have to acknowledge as impacting upon the way the institutions we have accepted to have a public basis would run. The importance of this consideration is that such institutions are also supported publicly by those with whom we are close. This point gives strong grounds for preserving our sense of justice.
Another element of the grounds of congruence is the way that the participation in the public good of the well-ordered society satisfies the Aristotelian Principle. The well-ordered society is one that realises to a pre-eminent degree the forms of human activity and the way in which the cooperation of persons safeguards the well-being of each one of us. To really share in the goods of this society we must acknowledge the principles that regulate activities. A final reason underpinning congruence is bound up with the Kantian conception of the person which states that acting justly is something we want to do inasmuch as we are free and equal rational beings.
Assuming that the reference to publicity, the Aristotelian Principle and the Kantian conception of the person provide the chief reasons within the "thin" theory of the good to underpin congruence we can now ask whether these reasons are decisive in motivating members of the well-ordered society to generally act in accordance with their sense of justice. It appears that this leads us to a question about how to balance contrary principles. But an element that has not yet been considered is what it is that acting from the sense of justice really requires of us. The congruence between it and our conception of the good depends upon the content of the specific notion of right that has determined the sense of justice taking the form it does. So the good of justice is, we are clear, not akin to that provided by classical utilitarianism which required us to sacrifice our interests when this would be necessary for the greater good of all. The reason why the principles of justice defended by Rawls does not have this stringency is due to the priority of the first principle of justice. It would be hazardous to freedom to accept the stringent requirements defended by writers such as Sidgwick. This is already a point in favour of the view that it is possible to act in accordance with the sense of justice as Rawls conceives it as such a sense of justice is not so stringent and out of keeping with the demands of common sense as the view of Sidgwick.
This does not mean that there are not possible costs to following our sense of justice in action. Certain things will be ruled out for us as possible actions if we follow it. This point is defended by Rawls by an extended comparison between acting from the sense of justice and acting from a view of love of others. The Kantian conception of the person underpins this point and shows grounds for giving first priority to our sense of justice. The principles of justice meet the conditions of finality, they are regulative of our behaviour and acting in accordance with other things is constrained by the claims of the principles of justice. The Kantian conception of the person points to the way that our freedom is best expressed by acting from the sense of justice. Acting against the sense of justice is therefore sure to produce feelings of guilt and shame and set for us a demanding standard of consistency.
It is possible that there are some persons, even in a well-ordered society, who do not take the affirmation of the sense of justice to be a good. For such people the thin theory of the good has proved insufficient to ground a regulative sentiment in favour of the sense of justice. The question of how to respond to such people requires recourse to partial compliance theory. We have seen that the principles of right are collectively rational and that affirmation of the sense of justice is a collective asset. Given this it is rational to authorise the measures required to maintain just institutions. The nature of those who have not found it part of their good to affirm the sense of justice is unfortunate for them and it is not required to provide sufficient reasons further to convince them. It would be true, however, if there were many such people that this would be an element of instability within the society and the degree to which such persons were present would effect the degree to which penal devices might be required within it. So long as there is no more stable conception of justice than the one Rawls has defined this point does not count against it.
In concluding the congruence argument Rawls specifies in more detail his definition of goodness. In a well-ordered society it is the case that behaving in a way that manifests a definite acceptance of the requirements of the sense of justice is good for each person within it. A well-ordered society is also a "good" society as it satisfies the principles of justice and enables a stable pattern to develop by which individuals come to affirm the sense of justice as regulative of their view of the good.
The final section of Chapter IX and of the book as a whole is mainly intended to address the question of what type of justification the work has produced for Rawls' theory. It is not a justification by reference to the view that there are self-evident principles, hence it is not a rationalist justification. It is also not a justification by means of reference to non-moral properties that are argued, by introducing appeals to common sense and science, to have some important normative significance. So it is also not a view that is broadly "realist" or "naturalist" and nor does it draw upon the justificatory strategies that would be appropriate for such views.
The three parts of the work are intended to make a unified argument by showing first the essentials of the structure of the view, then applying them to the examination of institutions and finally showing that the view is psychologically feasible. The first part of the argument proceeded by reasonable stipulations concerning choice. The second part related these stipulations to the ways that common sense comprehends the institutions required for our common way of life. The third part looked at questions of stability and congruence.
Rawls considers possible objections to the structure of justification his argument displays. It might be thought that Rawls' theory is grounded on a simple empirical appeal to agreement or that it depends on an unreasonably restrictive view of feasible conceptions in the choice situation. The response to the first part of this objection is that Rawls' theory proceeds from commonly held views. Now as to the charge that it is unreasonably restrictive in its consideration of alternatives it is less clear that leading candidates widely recognised are not all considered. This does not mean that all views are included and the basis of assessment of other views would require presentation of them and consideration of whether or how they related to views that have been looked at. The list considered is though one that arises from the history of moral philosophy.
The original position is intended to bring together reasonable constraints into a single conception so that the selection of principles of justice can proceed. The selection of these constraints is not arbitrary. Ordering and finality seem obvious criteria within the choice situation for example. Publicity, by contrast, ensures that the process of justification within the situation is one that can appeal to all parties involved and to be endorsed by all as something that is not chosen for special reasons by some part of the group using esoteric methods of choice. The original position is thus intended to be a kind of "constrained minimum" set of conditions. Each part of the conditions is reasonable taken singly and put together provide a criteria of right independent of the presumed good of any member of the situation. Disinterested motivation is assumed with regard to the parties and this asks little of the parties given the veil of ignorance. Part of what arises from assuming it is an obvious rational basis for freedom of conscience and convergence then on the priority of liberty.
The Kantian components of the theory are related now by Rawls to the way the theory is justified. The general conception of rational choice defines the way that autonomy and the moral law are to be understood as it does also provide a way of grasping the good of community. One thing that emerges clearly here however is that the Kantian conception of the person is part of the "Archimedean point" by means of which the basic structure of society can be judged. This occurs by means of the use of the original position to first determine the content of justice and the later reference back to what has emerged from it as the basis of our sense of justice. The original choice situation is one that allows for the interests that define parties to include determinate attachments. But the principles of justice are not derived from particular principles such as respect for persons. Rather the principles of justice are such as to give a basis for interpretation of such principles. The theory of justice is thus intended to give a rendering of Kantian ideas.
Once the original position is presented as the basis of the choice situation it provides a way that the social world can always be grasped and responded to. It is an objective situation that recognises autonomous decision. It is akin, says Rawls in his stirring conclusion, to seeing our situation sub specie aeternitatis. "Purity of heart, if one could attain it, would be to see clearly and to act with grace and self-command from this point of view."