Moral nihilism is the meta-ethical view that nothing is morally right or wrong. Moral nihilism is distinct from moral relativism, which allows for actions to be wrong relative to a particular culture or individual. It is also distinct from expressivism, according to which when we make moral claims, "We are not making an effort to describe the way the world is... we are venting our emotions, commanding others to act in certain ways, or revealing a plan of action". Nihilism does not imply that we should give up using moral or ethical language; some nihilists contend that it remains a useful tool.
Forms of nihilism
Moral nihilists agree that all claims such as 'murder is morally wrong' are not true. But different nihilistic views differ in two ways. Some may say that such claims are neither true nor false; others say that they are all false. Nihilists differ in the scope of their theories. Error theorists typically claim that it is only distinctively moral claims which are false; practical nihilists claim that there are no reasons for action of any kind; some nihilists extend this claim to include reasons for belief.
Ethical language: false versus not truth-apt
argues that moral assertions are only true if there are moral properties, but because there are none, all such claims are false. Other versions of the theory claim that moral assertions are not true because they are neither true nor false. This form of moral nihilism claims that moral beliefs and assertions presuppose the existence of moral facts that do not exist. Consider, for example, the claim that the present king of France is bald. Some argue that this claim is neither true nor false because it presupposes that there is currently a king of France, but there is not. The claim suffers from "presupposition failure". Richard argues for this form of moral nihilism under the name "fictionalism".
The scope question
Error theory is built on three principles:
There are no moral features in this world; nothing is right or wrong.
Therefore, no moral judgments are true; however,
Our sincere moral judgments try, but always fail, to describe the moral features of things.
Thus, we always lapse into error when thinking in moral terms. We are trying to state the truth when we make moral judgments. But since there is no moral truth, all of our moral claims are mistaken. Hence the error. These three principles lead to the conclusion that there is no moral knowledge. Knowledge requires truth. If there is no moral truth, there can be no moral knowledge. Thus moral values are purely chimerical The famous Cartesian hypothesis is of a demon who deceives me in all of my beliefs about the external world, while also ensuring that my beliefs are completely coherent. This possibility cannot be ruled out by any experiences or beliefs, because of how the deceiving demon is defined. This hypothesis is also contrary to my beliefs about the lake. So my beliefs about the lake are not justified, according to the above principle. And there is nothing special about my beliefs about the lake. Everything I believe about the external world is incompatible with the deceiving demon hypothesis. Skeptics conclude that no such belief is justified. This argument is often dismissed on the grounds that there is no reason to believe in a deceiving demon or that nobody really doubts whether there is an external world. In contrast, this form of argument is not subject to such objections when it is applied to morality, because some people really do adopt and even argue for a parallel skeptical hypothesis in morality: Moral Nihilism = Nothing is morally wrong. Moral nihilism here is not about what is semantically or metaphysically possible. It is just a substantive, negative, existential claim that there does not exist anything that is morally wrong.
The most prominent argument for nihilism is the argument from queerness. J. L. Mackie argues that there are no objective ethical values, by arguing that they would be queer :
If there were objective values, then they would be entities or qualities or relations of a very strange sort, utterly different from anything else in the universe.
For all those who also find such entities queer, there is reason to doubt the existence of objective values. In his book Morality without Foundations: A Defense of Ethical Contextualism, Mark Timmons provides a reconstruction of Mackie's views in the form of the two related arguments. These are based on the rejection of properties, facts, and relationships that do not fit within the worldview of philosophical naturalism, the idea "that everything—including any particular events, facts, properties, and so on—is part of the natural physical world that science investigates". Timmons adds, "The undeniable attraction of this outlook in contemporary philosophyno doubt stems from the rise of modern science and the belief that science is our best avenue for discovering the nature of reality". There are several ways in which moral properties are supposedly queer:
our ordinary moral discourse purports to refer to intrinsically prescriptive properties and facts "that would somehow motivate us or provide us with reasons for action independent of our desires and aversions"—but such properties and facts do not comport with philosophical naturalism.
given that objective moral properties supposedly supervene upon natural properties, the relation between the moral properties and the natural properties is metaphysically mysterious and does not comport with philosophical naturalism.
a moral realist who countenances the existence of metaphysically queer properties, facts, and relations must also posit some special faculty by which we have knowledge of them.
Responses and criticisms
responds to Mackie by saying: Other criticisms of the argument include noting that for the very fact that such entities would have to be something fundamentally different from what we normally experience—and therefore assumably outside our sphere of experience—we cannot prima facie have reason to either doubt or affirm their existence; therefore, if one had independent grounds for supposing such things to exist then the argument from queerness cannot give one any particular reason to think otherwise. An argument along these lines has been provided by e.g. Akeel.
