I want now to call attention to two limits on our subject-matter in this discussion.

First limit: Providing resources for what I have called normative legal scholarship is certainly not the only way in which philosophical learning enters into legal scholarship today. A good deal of philosophically informed legal scholarly work has aims that are, at least ostensibly, analytic rather than normative: to grasp what lawyers and judges mean when they use such basic expressions as "rights," "fault," "cause," "rule," "law," and "the rule of law;" to sort out the possible values and purposes to be served by punishments and other social sanctions; to explain the logical and grammatical workings of typical modes of legal reasoning such as rule-application and analogy; to explain what differentiates a legal order or system from other kinds of socially embedded normative orders; or otherwise to explore the relationships between legal norms and rules or principles of conduct drawn from other normative domains such as morality, religion, and manners.  Such scholarship will naturally draw from philosophical writings about these matters, of which there is a rich supply. Our focus here, however, will be on the use of philosophy in normative legal scholarship. (Of course, the field of philosophy is not the only possible source of extra-legal inspiration for normative legal scholarship. The field of economics, obviously, is another, and many normative legal scholars much prefer it, giving reasons we shall come to.)

Second limit: It is not all of "philosophy" that is involved here, or even all of moral philosophy, but only that part of moral philosophy that we may identify as "moral theory" -- that part that is interested in the production, analysis, criticism, and defense of what we may call "moral theories." But what is a "moral theory?"

A complete moral theory contains both a theory of the good and a theory of the right. "The good" is that which there is strongest reason to want or desire. "The right" is that which an actor ought to do (has strongest reason to do) in the circumstances of his or her action. A theory of the good is a claim about what it means for a human life to be going well or about what sorts of events and developments in their lives human beings have strongest reason to desire or approve. For example, theories of the good say (variously) that a human life goes well insofar the person living that life exercises a certain sort of deliberate control over its major directions and aims; or insofar as the life contributes to the well-being of others; or insofar as it is committed to finding and abiding by mutually satisfactory ways of cooperating with others whose specific aims and projects conflict with one's own; or insofar as it encompasses successful exercises of certain kinds of capacities -- say, for friendship, or leadership, or artistic creation. Other theories of the good quite differently say that the life goes well insofar as it is consumed with pleasant experiences, or passes without pain or frustration.

A theory of the right makes a claim about what an actor in a particular situation -- it could be a judge having to decide a case -- ought to do, all things considered, in view of some controlling theory of the good. Theories of the right of the sort that concern us here -- that is, theories of the right for lawmaking and law-application -- often differ with each other over questions about distribution. For example, it is common for theories of the right to affirm that every person is equally entitled to certain "freedoms" or dimensions of freedom (such as freedom of expression), but such theories differ over whether the ideal of equality of freedoms requires any measure of equality of access to material resources required for the effective exercise or enoyment of the freedoms in question. And here is another way in which theories of the right can differ over a question of distribution. Some theories of the right -- of which the "hard-nosed claim" to be described below is representative -- say that the lawmaker ought to act in the way that will lead to maximization of the good in society, regardless of how that total sum of good is distributed among persons, while others contrastingly say that the right aim is to show the respect and consideration that is due to the personhood of each individual, which requires lawmakers to act in the way required to achieve an equal distribution of the good to everyone, or at least assurance to everyone of adequate access to the good.

To say that a complete moral theory contains both a theory of the good and a theory of the right does not mean that a moral theory has to be anything high-falutin or out-of-the-ordinary. Consider the following hard-nosed claim:

Hard-nosed claim: Conditions of economic efficiency and political stability are known to be strongly conducive to the relative pleasantness of the lives led by the residents of any country where they prevail. Therefore, the practical requirements of economic efficiency and political stability ought always to be given controlling weight by judges interpreting the country's law. 

That claim looks pretty plain-minded -- not the sort of thing it takes a trained philosopher either to think up or to understand. Nevertheless, it contains a contestable moral argument, guided by a contestable moral theory.

The moral theory implicit in the hard-nosed claim can be rendered -- very roughly -- in two propositions -- 

(1) the right thing for a judge to do is to act in the way that will increase or maximize the total good of society, and

(2) the good consists in the pleasantness of human lives.

Add to those two propositions a third, non-moral, empirical claim about the sources and causes of pleasantness in human life -- specifically,

(3) economic efficiency and political stability are factors dominantly affecting the pleasantness of the lives people lead --

and you end up with the hard-nosed claim: Because economic efficiency and political stability tend to maximize the amount of that which there is strongest reason to want, namely, the pleasantness of human lives, the right thing for judges interpreting the Constitution to do is: interpret, insofar as possible, in ways that are maximally conducive to economic efficiency and political stability. But (1) is a philosophically contested theory of the right, and (2) is a philosophically contested theory of the good, so embedded in the hard-nosed claim is a moral theory that is very controversial among philosophers.  (Should that matter?)