Ethical naturalism

Overview

Ethical naturalism typically involves several related claims: that moral sentences express propositions, that some of these propositions are true, and that their truth depends on objective features of the world which are independent of human opinion and reducible to empirical or natural properties.

Ethical naturalism encompasses a range of views that attempt to reduce ethical properties, such as "goodness", to non-ethical properties. Different versions of ethical naturalism identify moral properties with different natural features, such as pleasure, human flourishing, or the satisfaction of preferences.

Many versions of ethical naturalism discussed in contemporary philosophy, such as Cornell realism, differ from the view that moral norms simply follow from how the world happens to be.

Types of naturalism

Philosophers often distinguish between different forms of ethical naturalism, including reductive and non-reductive versions. Reductive naturalists attempt to define moral properties in terms of descriptive natural properties, whereas non-reductive naturalists maintain that moral properties are part of the natural world but cannot be reduced through simple analytic definitions.

One influential form of non-reductive ethical naturalism is associated with Cornell realism, a position developed by philosophers including Richard Boyd, Nicholas Sturgeon, and David O. Brink. Cornell realists argue that moral properties are natural properties and can play explanatory roles in scientific accounts of the world, even if they cannot be defined through simple conceptual analysis. On this view, moral properties are often understood by analogy with other theoretical properties in science, whose identities may be discovered through empirical investigation rather than through purely conceptual analysis.

This view emerged partly as a response to earlier criticisms of ethical naturalism, such as Moore's open-question argument, and attempts to defend moral realism while rejecting non-naturalist accounts of moral properties.

History

Ideas associated with ethical naturalism appear in earlier philosophical traditions that attempted to explain morality in terms of human nature or natural facts. Elements of naturalistic thinking are often associated with Aristotle's account of human flourishing and virtue.

Twentieth-century metaethical debates renewed attention to whether moral properties could be identified with natural properties, particularly in response to criticisms such as Moore's open-question argument.

During the late twentieth century, several philosophers associated with so-called Cornell realism defended forms of ethical naturalism that attempted to reconcile moral realism with a broadly naturalistic worldview.

Relation to moral realism

Ethical naturalism is generally considered a form of moral realism because it holds that moral statements can be objectively true or false. However, it differs from non-naturalist forms of realism in claiming that moral facts ultimately depend on natural features of the world.

Fact–value distinction

Ethical naturalism is frequently discussed in relation to the fact–value distinction and the is-ought problem. Naturalist theories are often presented as challenging strong interpretations of this distinction by arguing that moral facts are grounded in natural facts about human behavior or social organisation.

Ethical theories associated with naturalism

• Altruism
• Consequentialism
• Consequentialist libertarianism
• Cornell realism
• Ethical egoism
• Evolutionary ethics
• Hedonism
• Humanistic ethics
• Natural law
• Natural-rights libertarianism
• Objectivism
• Utilitarianism
• Virtue ethics

Criticisms

Moore's open-question argument and his discussion of the naturalistic fallacy remain among the most influential critiques of ethical naturalism. Moore argued that for any proposed naturalistic definition of “good”, it remains meaningful to ask whether the natural property in question is itself good, suggesting that moral properties cannot be analytically reduced to natural properties.

R. M. Hare argued that moral language functions prescriptively rather than descriptively and therefore cannot be reduced to purely descriptive natural properties.

Moral nihilism

Some critics approach the debate from the perspective of moral nihilism, a form of moral anti-realism that denies the existence of objective moral facts or values. From this perspective, both naturalist and non-naturalist forms of moral realism are rejected. Critics in this tradition argue that attempts to ground morality in natural facts fail because there are no moral facts to explain in the first place.

Morality as a science

Research in fields such as evolutionary biology, psychology, and neuroscience has examined the origins and functions of moral behaviour and the natural bases of moral judgment.

Some philosophers and scientists, such as Sam Harris, have argued that moral questions can in principle be studied scientifically in terms of the well-being or flourishing of conscious creatures.

Physicist Sean M. Carroll has criticized this approach, arguing that attempts to frame morality as a scientific discipline risk extending scientific explanation beyond its appropriate domain.

Philosopher John Shook has also discussed the prospects for a scientific study of morality, arguing that empirical research may contribute to ethical inquiry even if philosophical disagreements about moral facts remain unresolved.