At about this time a different form of subjectivism was gaining currency on the Continent and to some extent in the United States. Existentialism was as much a literary as a philosophical movement. Its leading figure, the French philosopher Jean-Paul Sartre (1905–80), propounded his ideas in novels and plays as well as in his major philosophical treatise, Being and Nothingness (1943). Sartre held that there is no God, and therefore human beings were not designed for any particular purpose. The existentialists expressed this by stating that “existence precedes essence.” Thus, they made clear their rejection of the Aristotelian notion that one can know what the good for human beings is once one understands the ultimate end toward which human beings tend. Because humans do not have an ultimate end, they are free to choose how they will live. To say of anyone that he is compelled by his situation, his nature, or his role in life to act in a certain way is to exhibit “bad faith.” This seems to be the only term of disapproval the existentialists were prepared to use. As long as a person chooses “authentically,” there are no moral standards by which his conduct can be criticized.

This, at least, was the view most widely held by the existentialists. In one work, a pamphlet entitled Existentialism Is a Humanism (1946), Sartre backed away from so radical a subjectivism by suggesting a version of Kant’s idea that moral judgments be applied universally. He does not reconcile this view with conflicting statements elsewhere in his writings, and it is doubtful whether it represents his final ethical position. It may reflect, however, revelations during the postwar years of atrocities committed by the Nazis at Auschwitz and other death camps. One leading German prewar existentialist, Martin Heidegger (1889–1976), had actually become a Nazi. Was his “authentic choice” to join the Nazi Party just as good as Sartre’s own choice to join the French Resistance? Is there really no firm ground from which to compare the two? This seemed to be the outcome of the pure existentialist position, just as it was an implication of the ethical emotivism that was dominant among English-speaking philosophers. It is scarcely surprising that many philosophers should search for a metaethical view that did not commit them to this conclusion. The Kantian avenues pursued by Sartre in Existentialism Is a Humanism were also explored in later British moral philosophy, though in a much more sophisticated form.

Universal prescriptivism

In The Language of Morals (1952), the British philosopher R.M. Hare (1919–2002) supported some elements of emotivism but rejected others. He agreed that moral judgments are not primarily descriptions of anything; but neither, he said, are they simply expressions of attitudes. Instead, he suggested that moral judgments are prescriptions—that is, they are a form of imperative sentence. Hume’s rule about not deriving an “is” from an “ought” can best be explained, according to Hare, in terms of the impossibility of deriving any prescription from a set of descriptive sentences. Even the description “There is an enraged bull charging straight toward you” does not necessarily entail the prescription “Run!,” because one may have intentionally put oneself in the bull’s path as a way of committing suicide. Only the individual can choose whether the prescription fits what he wants. Herein, therefore, lies moral freedom: because the choice of prescription is individual, no one can tell another what is right or wrong.

Hare’s espousal of the view that moral judgments are prescriptions led reviewers of his first book to classify him with the emotivists as one who did not believe in the possibility of using reason to arrive at ethical conclusions. That this was a mistake became apparent with the publication of his second book, Freedom and Reason (1963). The aim of this work was to show that the moral freedom guaranteed by prescriptivism is, notwithstanding its element of choice, compatible with a substantial amount of reasoning about moral judgments. Such reasoning is possible, Hare wrote, because moral judgments must be “universalizable.” This notion owed something to the ancient Golden Rule and even more to Kant’s first formulation of the categorical imperative. In Hare’s treatment, however, these ideas were refined so as to eliminate their obvious defects. Moreover, for Hare universalizability was not a substantive moral principle but a logical feature of moral terms. This means that anyone who uses words such as right and ought is logically committed to universalizability.

To say that a moral judgment must be universalizable means, for Hare, that anyone who judges a particular action—say, a person’s embezzlement of a million dollars from his employer—to be wrong must also judge any relevantly similar action to be wrong. Of course, everything will depend on what is allowed to count as a relevant difference. Hare’s view is that all features may count, except those that contain ineliminable uses of words such as I or my or singular terms such as proper names. In other words, the fact that Smith embezzled a million dollars in order to take holidays in Tahiti whereas Jones embezzled the same sum to give to famine relief in Africa may be a relevant difference; the fact that the first crime benefited Smith whereas the second crime benefited Jones cannot be so.

This notion of universalizability can also be used to test whether a difference that is alleged to be relevant—for instance, skin colour or even the position of a freckle on one’s nose—really is relevant. Hare emphasized that the same judgment must be made in all conceivable cases. Thus, if a Nazi were to claim that he may kill a person because that person is Jewish, he must be prepared to prescribe that if, somehow, it should turn out that he is himself of Jewish origin, he should also be killed. Nothing turns on the likelihood of such a discovery; the same prescription has to be made in all hypothetically, as well as actually, similar cases. Since only an unusually fanatic Nazi would be prepared to do this, universalizability is a powerful means of reasoning against certain moral judgments, including those made by Nazis. At the same time, since there could be fanatic Nazis who are prepared to die for the purity of the Aryan race, the argument of Freedom and Reason recognizes that the role of reason in ethics does have limits. Hare’s position at this stage therefore appeared to be a compromise between the extreme subjectivism of the emotivists and some more objectivist view.

Subsequently, in Moral Thinking (1981), Hare argued that to hold an ideal—whether it be a Nazi ideal such as the purity of the Aryan race or a more conventional ideal such as doing justice irrespective of consequences—is really to have a special kind of preference. When asking whether a moral judgment can be prescribed universally, one must take into account all the ideals and preferences held by all those who will be affected by the action one is judging; and in taking these into account, one cannot give any special weight to one’s own ideals merely because they are one’s own. The effect of this notion of universalizability is that for a moral judgment to be universalizable it must ultimately result in the maximum possible satisfaction of the preferences of all those affected by it. Hare claimed that this reading of the formal property of universalizability inherent in moral language enabled him to solve the ancient problem of showing how moral disagreements can be resolved, at least in principle, by reason. On the other hand, Hare’s view seemed to reduce the notion of moral freedom to the freedom to be an amoralist or the freedom to avoid using moral language altogether.

Hare’s position was immediately challenged by the Australian philosopher J.L. Mackie (1917–81). In his defense of moral subjectivism, Ethics: Inventing Right and Wrong (1977), Mackie argued that Hare had stretched the notion of universalizability far beyond anything inherent in moral language. Moreover, Mackie insisted, even if such a notion were embodied in the ways in which people think and talk about morality, this would not show that the only legitimate moral judgments are those that are universalizable in Hare’s sense, because the ways in which people think and talk about morality may be mistaken. Indeed, according to Mackie, the ordinary use of moral language wrongly presupposes that moral judgments are statements about objective features of the world and that they therefore can be true or false. Against this view, Mackie drew upon Hume to argue that moral judgments cannot have the status of matters of fact, because no matter of fact can imply that it is morally right or wrong to act in a particular way (it is impossible, as Hume said, to derive an “ought” from an “is”). If morality is not to be rejected altogether, therefore, it must be allowed that moral judgments are based on individual desires and feelings.

Later developments in metaethics

Mackie’s suggestion that moral language takes a mistakenly realist view of morality effectively ended the preoccupation of moral philosophers with the analysis of the meanings of moral terms. Mackie showed clearly that such an analysis would not reveal whether moral judgments really can be true or false. In subsequent work, moral philosophers tended to keep metaphysical questions separate from semantic ones. Within this new framework, however, the main positions in the earlier debates reemerged, though under new labels. The view that moral judgments can be true or false came to be called “moral realism.” Moral realists tended to be either naturalists or intuitionists; they were opposed by “antirealists” or “irrealists,” sometimes also called “noncognitivists” because they claimed that moral judgments, not being true or false, are not about anything that can be known. The terminology was sometimes confusing, in particular because moral realism did not imply, as intuitionism and naturalism did earlier, that moral judgments are objective in the sense that they are true or false independently of the feelings or beliefs of the individual.