INTRODUCTION

The well-known moral realist Nicholas Sturgeon once wrote that any critical response to a philosophical position can be classified as either an “Oh yeah?” or a “So what?” In the case of the claim that much moral diversity is radical, and therefore less tractable than disagreements in other areas, realists usually pursue the “Oh yeah?”–line. In this chapter, however, I shall start to explore the “So what?”–response. Why is the diversity supposed to show that there are no objective moral facts?

According to one idea, the reason is that the latter claim provides the best explanation of the diversity. For example, in David Brink's view, the central premise is the thesis that “moral disputes are so pervasive and so intractable that the best explanation of this kind of disagreement is that there are no moral facts.”

Brink conceives of this as an a posteriori argument; as an argument that relies on premises whose evaluation requires empirical research. There are versions that are construed differently, versions that appeal to the mere possibility of radical disagreement. However, this chapter is devoted to versions that appeal to claims about the existing diversity. I shall argue that none of these versions strengthens anti-realism to any significant extent.

THE ARGUMENT FROM RELATIVITY

Many realists concede that, if a significant number of the existing moral disagreements were radical, realism would be in trouble, at least if we assume that this would mean that they cannot be rationally resolved.