Category mistake

A category mistake, or category error, is a semantic or ontological error by which a property is ascribed to a thing that could not possibly have that property. All (propositional) mistakes involve some sort of misascription of properties, so in a sense any mistake is a "category mistake": putting a thing into a class to which it does not belong. But a "category mistake" in colloquial philosophical usage seems to be the most severe form of misascription, involving the endorsement of what is in fact logically impossible. Thus the mistaken claim that "Most Americans are atheists" is not a category mistake, since it is merely contingently true that most Americans are theists. On the other hand, "Most bananas are atheists" is a category error. To show that a category mistake has been committed one must typically show that once the phenomenon in question is properly understood, it becomes clear that the claim being made about it could not possibly be true.

Gilbert Ryle

The term "category-mistake" was introduced by Gilbert Ryle in his book The Concept of Mind (1949) to remove what he argued to be a confusion over the nature of mind born from Cartesian metaphysics. Ryle alleged that it was a mistake to treat the mind as an object made of an immaterial substance because predications of substance are not meaningful for a collection of dispositions and capacities.

Specifically, the phrase is introduced in chapter 1, section 2. The first example he gives is of someone being shown Oxford or Cambridge, and after seeing colleges, libraries, playing fields, museums, scientific departments and administrative offices asks 'but where is the University?' 'The University is just the way in which all that he has already seen is organized' says Ryle. The visitor's mistake is presuming that a University is part of the category "units of physical infrastructure" or some such thing, rather than the category "institutions", say, which are far more abstract and complex conglomerations of buildings, people, procedures, and so on.

Ryle's second example is of a child witnessing the march-past of a division. After having had battalions, batteries, squadrons, etc. pointed out, the child asks when is the division going to appear. 'The march-past was not a parade of battalions, batteries, squadrons and a division; it was a parade of the battalions, batteries and squadrons of a division.' (Ryle's italics)

His third example is of a foreigner being shown a cricket match. After being pointed out batsmen, bowlers and fielders, the foreigner asks: 'who is left to contribute the famous element of team-spirit?'

He goes on to argue that the Cartesian dualism of mind and body rests on a category-mistake.

See also

• catachresis
• Colorless green ideas sleep furiously
• mixed metaphor

References