Moral skepticism (or moral scepticism) is a class of metaethical theories all members of which entail that no one has any moral knowledge. Many moral skeptics also make the stronger, modal claim that moral knowledge is impossible. Moral skepticism is particularly opposed to moral realism: the view that there are knowable and objective moral truths.
In at least one source, a class is a set in which an individual member can be recognized in one or both of two ways: a) it is included in an extensional definition of the whole set b) it matches an Intensional definition of one set member. By contrast, a "type" is an intensional definition; it is a description that is sufficiently generalized to fit every member of a set.
Meta-ethics is the branch of ethics that seeks to understand the nature of ethical properties, statements, attitudes, and judgments. Meta-ethics is one of the three branches of ethics generally studied by philosophers, the others being normative ethics and applied ethics.
Logical consequence is a fundamental concept in logic, which describes the relationship between statements that hold true when one statement logically follows from one or more statements. A valid logical argument is one in which the conclusion is entailed by the premises, because the conclusion is the consequence of the premises. The philosophical analysis of logical consequence involves the questions: In what sense does a conclusion follow from its premises? and What does it mean for a conclusion to be a consequence of premises? All of philosophical logic is meant to provide accounts of the nature of logical consequence and the nature of logical truth.
Some defenders of moral skepticism include Pyrrho, Aenesidemus, Sextus Empiricus, David Hume, J. L. Mackie (1977), Max Stirner, Friedrich Nietzsche, Richard Joyce (2001), Michael Ruse, Joshua Greene, Richard Garner, Walter Sinnott-Armstrong (2006b), James Flynn, and Walter Veit (2019). Strictly speaking, Gilbert Harman (1975) argues in favor of a kind of moral relativism, not moral skepticism. However, he has influenced some contemporary moral skeptics.
Pyrrho of Elis was a Greek philosopher of Classical antiquity and is credited as being the first Greek skeptic philosopher and founder of Pyrrhonism.
Aenesidemus was a Greek Pyrrhonist philosopher, born in Knossos on the island of Crete. He lived in the 1st century BC, taught in Alexandria and flourished shortly after the life of Cicero. Photius says he was a member of Plato's Academy, but he came to dispute their theories, adopting Pyrrhonism instead. Diogenes Laërtius claims an unbroken lineage of teachers of Pyrrhonism through Aenesidemus, with his teacher being Heraclides. However, little is known about the names between Timon of Phlius and Aenesidemus, so this lineage is suspect. Whether Aenesidemus re-founded the Pyrrhonist school or merely revitalized it is unknown.
Sextus Empiricus, was a physician and philosopher, who likely lived in Alexandria, Rome, or Athens. His philosophical work is the most complete surviving account of ancient Greek and Roman Pyrrhonism.
Moral skepticism divides into three subclasses: moral error theory (or moral nihilism), epistemological moral skepticism, and noncognitivism.All three of these theories share the same conclusions, which are:
Moral nihilism is the meta-ethical view that nothing is morally right or wrong.
Non-cognitivism is the meta-ethical view that ethical sentences do not express propositions and thus cannot be true or false. A noncognitivist denies the cognitivist claim that "moral judgments are capable of being objectively true, because they describe some feature of the world". If moral statements cannot be true, and if one cannot know something that is not true, noncognitivism implies that moral knowledge is impossible.
However, each method arrives at (a) and (b) by different routes.
Moral error theory holds that we do not know that any moral claim is true because
Epistemological moral skepticism is a subclass of theory, the members of which include Pyrrhonian moral skepticism and dogmatic moral skepticism. All members of epistemological moral skepticism share two things: first, they acknowledge that we are unjustified in believing any moral claim, and second, they are agnostic on whether (i) is true (i.e. on whether all moral claims are false).
Finally, Noncognitivism holds that we can never know that any moral claim is true because moral claims are incapable of being true or false (they are not truth-apt). Instead, moral claims are imperatives (e.g. "Don't steal babies!"), expressions of emotion (e.g. "stealing babies: Boo!"), or expressions of "pro-attitudes" ("I do not believe that babies should be stolen.")
In philosophy, to say that a statement is truth-apt is to say that it could be uttered in some context and would then express a true or false proposition.
Universal prescriptivism is the meta-ethical view which claims that, rather than expressing propositions, ethical sentences function similarly to imperatives which are universalizable—whoever makes a moral judgment is committed to the same judgment in any situation where the same relevant facts obtain.
Emotivism is a meta-ethical view that claims that ethical sentences do not express propositions but emotional attitudes. Hence, it is colloquially known as the hurrah/boo theory. Influenced by the growth of analytic philosophy and logical positivism in the 20th century, the theory was stated vividly by A. J. Ayer in his 1936 book Language, Truth and Logic, but its development owes more to C. L. Stevenson.
Moral error theory is a position characterized by its commitment to two propositions: (i) all moral claims are false and (ii) we have reason to believe that all moral claims are false. The most famous moral error theorist is J. L. Mackie, who defended the metaethical view in Ethics: Inventing Right and Wrong (1977). Mackie has been interpreted as giving two arguments for moral error theory.
The first argument people attribute to Mackie, often called the argument from queerness,holds that moral claims imply motivation internalism (the doctrine that "It is necessary and a priori that any agent who judges that one of his available actions is morally obligatory will have some (defeasible) motivation to perform that action" ). Because motivation internalism is false, however, so too are all moral claims.
The other argument often attributed to Mackie, often called the argument from disagreement,maintains that any moral claim (e.g. "Killing babies is wrong") entails a correspondent "reasons claim" ("one has reason not to kill babies"). Put another way, if "killing babies is wrong" is true then everybody has a reason to not kill babies. This includes the psychopath who takes great pleasure from killing babies, and is utterly miserable when he does not have their blood on his hands. But, surely, (if we assume that he will suffer no reprisals) this psychopath has every reason to kill babies, and no reason not to do so. All moral claims are thus false.
All versions of epistemological moral skepticism hold that we are unjustified in believing any moral proposition. However, in contradistinction to moral error theory, epistemological moral skeptical arguments for this conclusion do not include the premise that "all moral claims are false." For example, Michael Rusegives what Richard Joyce calls an "evolutionary argument" for the conclusion that we are unjustified in believing any moral proposition. He argues that we have evolved to believe moral propositions because our believing the same enhances our genetic fitness (makes it more likely that we will reproduce successfully). However, our believing these propositions would enhance our fitness even if they were all false (they would make us more cooperative, etc.). Thus, our moral beliefs are unresponsive to evidence; they are analogous to the beliefs of a paranoiac. As a paranoiac is plainly unjustified in believing his conspiracy theories, so too are we unjustified in believing moral propositions. We therefore have reason to jettison our moral beliefs.
There are two different opinions that may follow from moral skepticism.
Amoralism is the idea that we should abandon morality.
John E. Hare claims there are some reasons to obey moral rules. He claims that amoralists are logically consistent, but have plenty of disadvantages in their lives.
Criticisms of moral skepticism come primarily from moral realists. The moral realist argues that there is in fact good reason to believe that there are objective moral truths and that we are justified in holding many moral beliefs. One moral realist response to moral error theory holds that it "proves too much"—if moral claims are false because they entail that we have reasons to do certain things regardless of our preferences, then so too are "hypothetical imperatives" (e.g. "if you want to get your hair-cut you ought to go to the barber"). This is because all hypothetical imperatives imply that "we have reason to do that which will enable us to accomplish our ends" and so, like moral claims, they imply that we have reason to do something regardless of our preferences.
If moral claims are false because they have this implication, then so too are hypothetical imperatives. But hypothetical imperatives are true. Thus the argument from the non-instantiation of (what Mackie terms) "objective prescriptivity" for moral error theory fails. Russ Shafer-Landau and Daniel Callcut have each outlined anti-skeptical strategies. Callcut argues that moral skepticism should be scrutinized in introductory ethics classes in order to get across the point that "if all views about morality, including the skeptical ones, face difficulties, then adopting a skeptical position is not an escape from difficulty."
Epistemology is the branch of philosophy concerned with the theory of knowledge.
Ethics or moral philosophy is a branch of philosophy that involves systematizing, defending, and recommending concepts of right and wrong conduct. The field of ethics, along with aesthetics, concerns matters of value, and thus comprises the branch of philosophy called axiology.
Ethical naturalism is the meta-ethical view which claims that:
Skepticism or scepticism is generally a questioning attitude or doubt towards one or more items of putative knowledge or belief or dogma. It is often directed at domains, such as the supernatural, morality, theism, or knowledge. Formally, skepticism as a topic occurs in the context of philosophy, particularly epistemology, although it can be applied to any topic such as politics, religion, and pseudoscience.
The theory of justification is a part of epistemology that attempts to understand the justification of propositions and beliefs. Epistemologists are concerned with various epistemic features of belief, which include the ideas of justification, warrant, rationality, and probability. Loosely speaking, justification is the reason that someone (properly) holds a belief.
Moral relativism may be any of several philosophical positions concerned with the differences in moral judgments across different people and cultures. Descriptive moral relativism holds only that some people do in fact disagree about what is moral; meta-ethical moral relativism holds that in such disagreements, nobody is objectively right or wrong; and normative moral relativism holds that because nobody is right or wrong, we ought to tolerate the behavior of others even when we disagree about the morality of it.
Moral realism is the position that ethical sentences express propositions that refer to objective features of the world, some of which may be true to the extent that they report those features accurately. This makes moral realism a non-nihilist form of ethical cognitivism with an ontological orientation, standing in opposition to all forms of moral anti-realism and moral skepticism, including ethical subjectivism, error theory ; and non-cognitivism. Within moral realism, the two main subdivisions are ethical naturalism and ethical non-naturalism.
Philosophical skepticism is a philosophical school of thought that questions the possibility of certainty in knowledge. Skeptic philosophers from different historical periods adopted different principles and arguments, but their ideology can be generalized as either (1) the denial of possibility of all knowledge or (2) the suspension of judgement due to the inadequacy of evidence.
Groundwork of the Metaphysics of Morals is the first of Immanuel Kant's mature works on moral philosophy and remains one of the most influential in the field. Kant conceives his investigation as a work of foundational ethics—one that clears the ground for future research by explaining the core concepts and principles of moral theory and showing that they are normative for rational agents. Kant aspires to nothing less than this: to lay bare the fundamental principle of morality and show that it applies to us. In the text, Kant provides a groundbreaking argument that the rightness of an action is determined by the character of the principle that a person chooses to act upon. Kant thus stands in stark contrast to the moral sense theories and teleological moral theories that dominated moral philosophy at the time he was writing. Central to the work is the role of what Kant refers to as the categorical imperative, the concept that one must act only according to that precept which he or she would will to become a universal law.
Cognitivism is the meta-ethical view that ethical sentences express propositions and can therefore be true or false, which noncognitivists deny. Cognitivism is so broad a thesis that it encompasses moral realism, ethical subjectivism, and error theory.
Evidentialism is a thesis in epistemology which states that one is justified to believe something if and only if that person has evidence which supports his or her belief. Evidentialism is therefore a thesis about which beliefs are justified and which are not.
Ethical intuitionism is a family of views in moral epistemology. At minimum, ethical intuitionism is the thesis that our intuitive awareness of value, or intuitive knowledge of evaluative facts, forms the foundation of our ethical knowledge.
Contextualism describes a collection of views in philosophy which emphasize the context in which an action, utterance, or expression occurs, and argues that, in some important respect, the action, utterance, or expression can only be understood relative to that context. Contextualist views hold that philosophically controversial concepts, such as "meaning P", "knowing that P", "having a reason to A", and possibly even "being true" or "being right" only have meaning relative to a specified context. Some philosophers hold that context-dependence may lead to relativism;.
Broadly speaking, fallibilism is the philosophical claim that no belief can have justification which guarantees the truth of the belief. However, not all fallibilists believe that fallibilism extends to all domains of knowledge.
Trivialism is the logical theory that all statements are true and that all contradictions of the form "p and not p" are true. In accordance with this, a trivialist is a person who believes everything is true.
Moral sense theory is a theory in moral epistemology and meta-ethics concerning the discovery of moral truths. Moral sense theory typically holds that distinctions between morality and immorality are discovered by emotional responses to experience. Some take it to be primarily a view about the nature of moral facts or moral beliefs —this form of the view more often goes by the name "sentimentalism". Others take the view to be primarily about the nature of justifying moral beliefs —this form of the view more often goes by the name "moral sense theory". However, some theorists take the view to be one which claims that both moral facts and how one comes to be justified in believing them are necessarily bound up with human emotions.
Richard Joyce is a British-Australian-New Zealand philosopher, known for his contributions to the fields of meta-ethics and moral psychology. He is Professor of Philosophy at Victoria University of Wellington.