Mackie’s Error Theory

screen-capture-1“There are no objective values.”  So starts the first chapter of J.L. Mackie’s book, Ethics: Inventing Right and Wrong, where he argues that there are no objective, universally prescriptive moral facts.

His view is a cognitivist view, which means that our moral judgments express believes that have truth-value, but it is not an example of moral realism.  Mackie argued that all of our moral judgments and beliefs are false.  This is why it is called “Error Theory.”  How does he argue for this position?

His argument combines a conceptual claim about our moral judgments and an ontological claim about the existence of moral facts.

1) Conceptual claim: Our moral concepts are concepts of universally prescriptive, categorical facts in the world.

2) Ontological claim: There are no such facts in the world.

Since there is nothing in the world that corresponds to our beliefs about moral facts, our moral beliefs and claims are all false.  That is why Mackie’s view is called Error Theory, because we are literally in error.

Mackie argues for (1) by showing that many philosophers in the Western tradition have defended objective moral values.  While acknowledging that many thinkers are moral subjectivists he says “the main tradition of European moral philosophy includes the contrary claim, that there are objective values of just the sort I have denied,” (p. 30).  He cites philosophers like Plato, Kant, Sidgwick, Aristotle, Samuel Clarke, Hutcheson, Richard Price, and says Hume noticed the prevalence of the objectivist tradition as well.  He also argues that the objectivist tradition has a firm basis in ordinary thought.  When many people ask if a certain action is wrong, they are not asking what they feel about the action or what benefit they think it will give them, they are asking if the action itself is wrong.  Mackie also claims that existentialism and its influence on people shows that people tend to objectify their concerns.  People who cease to believe that objective moral facts or values exist tend to begin believing that nothing matters at all; that life has no purpose.  This suggests that those people were objectifying their moral judgments so that they were something external to them, not just aspects of their own ideas, thoughts, and desires (p. 34).

Mackie argues for (2) in a few different ways, but the argument I will focus on here is the argument from queerness.

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.  Correspondingly, if we were aware of them, it would have to be by some special faculty or moral perception or intuition, utterly different from our ordinary ways of knowing everything else. (p. 38)

In order to argue that moral facts do not exist, Mackie combines a metaphysical argument with an epistemological argument.  The metaphysical argument is that moral facts would be very “queer” properties unlike any other kinds of properties we know.  Moral facts are the kinds of things that have a demand for an action built into them.  They are prescriptive facts telling us how we ought to act.  The facts that we are all acquainted with, however, are prescriptively inert.  The facts or properties that we are all familiar with, physical properties, do not have demands for certain actions built into them.  They do not tell us how things ought to be, they just tell us how things are.  They are descriptive rather than prescriptive. These physical properties, which are descriptive properties that tell us how things are, are the kinds of properties that we are very well acquainted with and they are explicable on naturalism.  Moral properties, which are prescriptive properties that tell us how things ought to be, are strange and not easily explainable on naturalism, since the moral properties themselves would not be natural.

The epistemological argument is that we would need a special faculty that was able to detect these moral properties.  We have different faculties for detecting things in the world, and these faculties are how we gain knowledge about the world.  For example, our eyes pick up light and allow us to see, our noses detect scents in the air and allow us to smell, our ears detect the vibrations in the air and allow us to hear sound.  Through these different faculties we detect different things in the world and learn about them.  But what kind of faculty would we need to have in order to detect non-physical, universally prescriptive moral facts?  It is not clear what on earth this faculty could be or how we can gain knowledge of moral facts through it.  So Mackie concludes from this that we have good reason to reject the actual existence of moral facts.

To sum up, Mackie claims that our moral concepts are concepts of universally prescriptive facts, but these facts do not exist in the world, so our moral concepts are literally false.  He argues against their existence by showing that such facts would be metaphysically “queer” on naturalism and it is not clear how we would even know their existence.

I think Mackie’s moral theory is likely to be true if naturalism is true.  If someone is a naturalist, he would have to deny moral facts because they are not the kinds of things that would be natural.  If someone thinks that moral facts do exist, then he has reason to reject naturalism.


(1) Mackie, J. L. Ethics: Inventing Right and Wrong. Middelessex: Penguin, 1990. Print.

(2) Miller, Alexander. An Introduction to Contemporary Metaethics. Cambridge, UK: Polity, 2003. Print.

About Guest Contributor

KyleKyle Hendricks is a blogger of  Into the Harvest, a blog that reflects his thoughts on Philosophy of Religion and Theology.

Kyle is an awesomely gifted and careful Christian thinker. He graduated from The University of Missouri-Columbia with a B.A. in philosophy and is doing his M.A. program in philosophy at Biola University. Kyle works part-time for Stand to Reason.