Here Hare wants to offer a brief summary of the theory of the book as a whole, an outline of the main points of the theory. The book is designed to defend the thesis that what makes something morally obligatory for us is that God commands it, and what makes something morally wrong for us is that God prohibits it. Hare thinks the fact that divine command is so central to all three Abrahamic traditions, and that so many of the same problems arise in all three about the relation between divine command and human reason, should be taken as confirmation.

God is taken in this book to be the supreme good, manifested in three ways. First, God is the creator of all that exists other than God, and God maintains it and is present to it once created. Second, God gives us revelation, and for the purposes of this book the primary revelation is of the divine will for our willing, which God gives us in command. Finally, God redeems us, by bringing us to that union with God that is our proper end. These three functions (creation, revelation, and redemption) can be expressed in terms of a threefold sovereign role that God has over the created order, by analogy with human sovereignty. God has legislative, executive, and judicial functions. God makes and promulgates the law by command; God runs the universe and sustains its order; and God judges us and punishes and saves us.

Human beings are created as rational animals through the processes of evolution. We have the purpose of a kind of loving union with God that’s available only to rational animals. Each of us has, however, not merely the purpose common to the whole species, but a particular purpose (unique to the individual) of a kind of love of God particular to that individual. Our destination is a realm in which all these individual kinds of love are conjoined. We all have the same basic value because we all have a call from God of this unique kind. We are individual centers of agency, in time, free, and language users, features that put constraints on what we should take to be a divine command. From these constraints, we can deduce a presumption against taking anything to be a divine command that requires breaching these constraints. We’re born with a predisposition to respond to the command, but a propensity to put our own happiness above the command. We are in that way a mixture, but the predisposition is essential to us, and the propensity is not.

Our power to accept or reject the command is made possible only by God’s sustaining power, and God in the second decree brings all things to good. The relation between our freedom and God’s power is that we are like a lake and God’s power is like the flow in that lake from a hidden spring.

Moral obligation can be both universal and particular. It’s universal when it has all human beings in the scope of the subjects who are commanded to act and the scope of the beneficiaries or victims of that action. Commands are a species of prescription, and we can distinguish five types of divine prescriptions: precepts, prohibitions, permissions, counsels, and directly effective commands. God has objective authority over all human beings, whether they recognize it or not, because God’s commands give all human beings rightful reason to comply, given God’s threefold sovereign role already described. The reasons are rightful because God’s commands make obligatory the good things that God prescribes, all of which take us to our proper end by the path God has selected for us, and our obedience is an expression of our love for God, which is good in itself and our end.

There are at least five objections to Hare’s thesis. One is that it produces an infinite regress. But the principle that God is to be loved is known from its terms: we know that if something is God, it’s to be loved, but to love God is to obey God, and so we can know from its terms the principle that God is to be obeyed.

A second objection is that the thesis makes morality arbitrary. Could not just anything be obligatory if God were to command it? The solution to this worry is that there is a distinction between the good and the obligatory. The thesis of Hare’s book is that God’s command makes something obligatory. When a person judges that a thing is good, she expresses an attraction to it and says that it deserves to attract her. There is a prescriptivist or expressivist side to this and a realist side. The prescriptivist side is that the evaluative judgment expresses some state of desire or emotion or will. The realist side is that there is some value property that she claims belongs to the thing, in virtue of which her state of desire or emotion or will is appropriate. The goodness might reside in resemblance to God. It might also reside in the union with God that is the human destination, or what leads to this union, or what manifests God by displaying God’s presence. If God is supremely good, union with God must also be good as an end, and so must the path to this end be good as a means. God commands only what is consistent with this destination, and thus the command is not arbitrary in the contemporary sense, in which what is arbitrary ignores some consideration that is relevant to a decision.

The third objection is this: If God commands only what is good, is God’s command redundant? Hare again makes a distinction: the moral law can’t be deduced from our nature, but it fits our nature exceedingly well. There are two kinds of deduction we should deny. It might be thought that we could fix the reference of ‘good’ by looking at what most people, most of the time, think is good. But this does not fit the fact that we could be, and in fact are, wrong much of the time in our evaluation. An examination of Greek ethics and its stress on the competitive goods illustrates this. The second kind of deduction we should avoid is the deduction of virtue from our human form of life, even though there is a goodness of organisms that can be deduced from their simply being alive. The human form of life does indeed put a constraint on what we should conceive our virtues to be, but a large part of our conception of virtue is constituted by our ideals. And these can’t be deduced from our form of life, unless we have already screened our description of this form of life through our ideals. The central reason for the failure of this deduction is the mixture in both our natural inclinations and our ideals between what deserves to attract us in this way and what does not so deserve. The danger of some kinds of natural law theory is that God disappears into creation, in the sense that, because we think we can get morality from our nature, we think we do not need a personal divine commander. But creation itself, including our created nature, is not yet sufficiently complete for us to deduce from it how we should live. Reason (in the sense of looking at our nature) can be thought of as a junior partner in determining our duties, and it’s indispensable in disputes between traditions. But its results are not sufficiently determinate to tell us how to live, and we need the revelation of divine command in addition.

A fourth objection is that we live in a pluralist society, and appealing to God’s commands is inappropriate for conduct in the public square in such a society. The reply to this objection is twofold. First, it is discriminatory against religious believers to require them to shed their most basic commitments in public dialogue. Second, there is not enough common ground between all the parties to public conversation so that we could get good policy by sticking to the lowest common denominator.

A fifth objection is that, even if God were to give us commands, we are too unreliable as receivers of them to make them the final arbiters of our moral decisions. Too many bad people have appealed to divine commands in justifying their actions. The question here pertains to what sort of access to the commands we have. One way to proceed is to work out a rational ethical decision procedure and then say simply that God commands us to follow it. But the Abrahamic faiths have additional resources in the content of the narratives they give us of God’s dealing with human beings, in the procedures they prescribe for checking with other members of the community, and in the phenomenology they describe as characteristic of the reception of divine command. They can say that direct divine commands present themselves with clarity and distinctness, external origination, familiarity, authority, and providential care.

Finally, we should deny another thesis found in some forms of natural law theory, the thesis of eudaemonism that we should choose everything for the sake of happiness. We need instead a dual structure of motivation, according to which happiness is properly one of our ends, but we are also to be moved by what is good in itself independently of our happiness. The notion of happiness is not just pleasure. It includes an ideal element, so that we would not count a person in a pleasure-machine as “really” happy. But it is self-indexed, in the sense that the agent pursues it as her own good, and this makes eudaemonism unacceptably self-regarding.

Various defenses of eudaemonism should be rejected, like this one: happiness includes sympathetic pleasures. This should be rejected because sympathetic pleasures are limited in a way that morality should want to transcend. A second defense is that reason brings impartiality with it, and so our good as rational beings requires that we follow the moral law. But the notion of reason here simply begs the question. A third defense is to propose that the interests of the whole of creation form a nested hierarchy, so that, if the agent correctly sees this order, she will see that her good is necessarily consistent with the good of the whole. But it’s not hard to think of cases of real conflict, or at least possible conflict, between interests, in which case the question arises of whether any self-indexed good should take the priority. Finally, we can revise the third defense so that the agent perfects herself by identifying with God who is self-transcending. But, if she thereby loses attachment to self-indexed goods, this revision becomes unacceptably self-neglecting. We need a dual structure of motivation. We should hold that happiness and morality are indeed conjoined, but not because of some necessity in the nature of happiness or in the nature of morality, but because of the free benevolence of the supersensible author of nature.