The Disunity of Morality and Why it Matters to Philosophy

What can moral psychology and neuroscience contribute to moral philosophy? Descriptive sciences cannot directly entail normative conclusions, as Hume and Moore taught. Nonetheless, science still might play an important role in a larger argument (such as an inductive inference to the best explanation) with a normative conclusion. In addition, when philosophical moral theories depend on empirical presuppositions and premises, psychology and neuroscience can test those assumptions. This latter use of moral psychology and neuroscience is what we will try to exemplify here.For centuries, moral philosophers have proposed various theories about moral judgments. Recently moral psychologists and neuroscientists have joined die fray and developed descriptive accounts of how moral judgments operate in our minds. AU of this work in all of these fields regularly assumes that something is common and peculiar to all and only moral judgments that make them worthy of study as a unified topic. In mis paper, we will use empirical research (including some neuroscience) in conjunction with philosophical methods to argue against that assumption.1 Then we will discuss implications of giving it up.1. What Is Unity?Consider mineralogy. Quartz comes in many colors, but it is still a single mineral because the different types of quartz have the same basic chemical composition. The colors are due to impurities. In contrast, jade is not a unified mineral. Jade consists of two subtypes - jadeite and nephrite - with different chemical compositions: Jadeite is a type of pyroxene, and nephrite is a type of tremolite. Because of these chemical differences, it would be silly for a mineralogist to try to formulate a precise theory of jade in general. If a mineralogist wants to learn physical properties of jade, such as its density, hardness, and solubilities, the mineralogist will have to study Jadeite and nephrite separately. A general theory can work only if its subject matter is unified in the right way.A group of things is unified in the relevant way if and only if they share some feature that enables important universal generalizations about its distinctive properties. The shared feature might be content, structure, function, source, or almost anything else. The group is unified only if some such feature enables generalizations that hold not just usually but universally in all cases. Moreover, those generalizations must be important in illuminating the nature or effects of the phenomena.2. What Is a Moral Judgment?Whether moral judgments are unified in this way depends, of course, on what counts as a moral judgment. If someone stipulates that moral judgments include only judgments based on God's commands, then all of these moral judgments will be unified by their basis in God's commands. But then if someone else proclaims that all moral judgments must serve the good of society, then all of these moral judgments will be unified by their connection to social good. Defenders of each view can simply deny that any judgment that seems to be a moral judgment is really a moral judgment if it doesn't don't have to do with God's commands or the good of society. Unfortunately, that easy move is cheating, just as it would be cheating to deny that nephrite is really jade because it's different from jadeite. One could just as easily deny that jadeite is jade because it's different from nephrite. To avoid such cheating and pointless disputes, we need to specify what counts as jade or as a moral judgment in some way that does not beg the question and make the view empty.Accordingly, we define moral judgments to include all judgments that are intended to resemble paradigm moal judgments. The judger's intention is what makes the judgment moral. If people who say that homosexuality is wrong intend to be saying that homosexuality violates standards that they do or would see as moral in much the same way as exemplars that they take to be paradigms of moral judgment, and if they intend to be denying judgments that they also take to be similarly moral in nature, then their judgment is a moral judgment for our purposes. …