Peter Fosl

Although many of the concepts and distinctions used in philosophy were first formulated many years ago, philosophers are still generating new and useful tools. In fact, one often has the experience of reading a distinction being made for the first time and wondering how we got on for so long without it.

One such recent contribution is Bernard Williams's distinction between thick and thin ethical concepts. Thin ethical concepts are ones such as “good”, “bad”, “right” and “wrong”. Such terms are very general and leave it open as to what precisely constitutes them. In this respect they stand almost as placeholders for a specific theory to flesh out later.

For example, if I say “one should maximise the good”, I really haven't said what you should do. That depends on what the good is. If the good is human happiness, then I must maximise human happiness. But if the good is a life free of sin, I will probably be required to behave in ways rather different from those that maximise happiness – in this life, anyway.

Thin concepts thus allow for wide variations in how they are understood. Thick concepts, on the other hand, carry with them a more substantive (but not necessarily complete) meaning.

We may disagree about when “gratitude”, for example, is ethically required, but we all understand that gratitude is the appropriate recognition of a good deed towards oneself, family or group and that gratitude is a morally virtuous emotion. This is what makes it a thick ethical concept.

Another example of a thick ethical concept would be “deceit”. Deceit is a morally bad form of deception. Although we may disagree as to whether a particular act should be classified as deceit or, say, a white lie, the term “deceit” itself carries with it both a clear enough idea of what it is and whether it is morally good or bad.

The distinction is extremely useful in discussions about moral theory. Some debates require thin concepts, some thick ones, and it is useful to be able to distinguish the two and identify which is appropriate. For instance, metaethics is the study of the general nature of ethics and ethical claims. An example of a metaethical question might be, “is ethics about objective features of the real world?” To answer this question you need to consider whether statements such as “murder is wrong” describe facts about the world or something else, such as our feelings about the world. In such discussions, thin ethical concepts are all that is required, since we are not arguing about whether this or that moral judgement is correct but about the nature of moral judgements themselves.

When, however, we are discussing substantive issues in ethics, thicker concepts are required. For instance, if I want to argue that assisted suicide is ethically unjustifiable on the grounds that the taking of a human life is always wrong, I need to be able to say why it is wrong and what specifically I mean by wrong. To do this I need a substantive account of ethical concepts such as “wrong” and “murder”. General conceptions of what ethics is and the use of mere placeholders won't do.

An advantage of the terms thick and thin over other distinctions (such as metaethics versus normative or substantive ethics) is that it doesn't presume a sharp distinction. Thick and thin are not flip sides of one coin but opposite ends of a continuum, between which terms can be thicker or thinner.

That means that this distinction captures both a real difference between two endpoints of the spectrum while allowing for the shades of grey in between.

Peter S Fosl (pfosl@transy.edu) is associate professor of philosophy at Transylvania University. This series is adapted from The Philosopher's Toolkit: A Compendium of Philosophical Concepts and Methods by Julian Baggini and Peter S Fosl (Blackwell).