In philosophy

Philosophy

Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...

, a thick concept (sometimes: thick normative concept, or thick evaluative concept) is a kind of concept that both has a significant degree of descriptive content and is evaluatively loaded. Paradigmatic examples are various virtue

Virtue

Virtue is moral excellence. A virtue is a positive trait or quality subjectively deemed to be morally excellent and thus is valued as a foundation of principle and good moral being....

s and vice

Vice

Vice is a practice or a behavior or habit considered immoral, depraved, or degrading in the associated society. In more minor usage, vice can refer to a fault, a defect, an infirmity, or merely a bad habit. Synonyms for vice include fault, depravity, sin, iniquity, wickedness, and corruption...

s such as courage, cruelty, truthfulness and kindness. Courage for example, may be given a rough characterization in descriptive terms as '…opposing danger to promote a valued end'. At the same time, characterizing someone as courageous typically involves expressing a pro-attitude, or a (prima facie) good-making quality – i.e. an evaluative statement.

A middle position

Thick concepts thus seem to occupy a 'middle position' between (thin) descriptive concepts and (thin) evaluative concepts. Descriptive concepts such as water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

, gold

Gold

Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

, length

Length

In geometric measurements, length most commonly refers to the longest dimension of an object.In certain contexts, the term "length" is reserved for a certain dimension of an object along which the length is measured. For example it is possible to cut a length of a wire which is shorter than wire...

and mass

Mass

Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...

are commonly believed to pick out features of the world rather than provide reasons for action, whereas evaluative concepts such as right and good are commonly believed to provide reasons for action rather than picking out genuine features of the world. This 'double feature' of thick concepts has made them the point of debate between moral realists

Moral realism

Moral realism is the meta-ethical view which claims that:# Ethical sentences express propositions.# Some such propositions are true.# Those propositions are made true by objective features of the world, independent of subjective opinion....

 and moral expressivists

Expressivism

Expressivism in meta-ethics is a theory about the meaning of moral language. According to expressivism, sentences that employ moral terms–for example, “It is wrong to torture an innocent human being”–are not descriptive or fact-stating; moral terms such as “wrong,” “good,” or “just” do not refer...

. Moral realists have argued that the world-guided content and the action-guiding content cannot be usefully separated, indicating that competent use of thick concepts constitutes ethical knowledge. Expressivists, favoring an account of moral values as attitudes projected onto the world, wants to uphold a distinction between the (morally neutral) descriptive feature of a thick concept and the evaluative attitudes that typically goes with them.

Two accounts of thick concepts

As mentioned above, thick concepts seem to combine the descriptive features of natural concepts such as water with an evaluative content similar to the thin evaluative concepts such as good and right. How are we to understand this ‘combination’? Many theorists treat it as a conjunctive: a thick concept should be analyzed as a conjunction of a descriptive part and an evaluative part, which, at least in principle may be separated. A basic feature of this analysis is thus that the descriptive content of a thick concept may be given in absence of the evaluative content. Returning to the example of courage, ‘…is courageous’ could on this account be analyzed as something along the lines of ‘…opposing danger to promote a valued end’ and ‘this is (prima facie) good-making’. The evaluative part, on this view, may thus be characterized as a ‘prescriptive flag’ attached to the concept. It is, on this view, in principle possible to construct a completely descriptive concept – i.e. without evaluative force – that picked out the same features of the world.

This account of thick concepts has been criticized by other theorists, notably of moral realist persuasion. In their view, the only way to understand a thick concept is to understand the descriptive and evaluative aspects as a whole. The idea is that for a thick concept, the evaluative aspect is profoundly involved in the practice of using it; one cannot understand a thick concept without understanding also its evaluative point. Therefore, descriptive terms cannot completely fill in the ‘along the lines’ of a description such as ‘…opposing danger to promote a valued end’. These descriptions may allow the novice to see the salient features. However a hooking on to the evaluative perspective allows the person to fully understand the 'thick' concept.