Category mistake

A category mistake (or category error, categorical mistake, or mistake of category), is a semantic or ontological error in which things belonging to a particular category are presented as if they belong to a different category, or, alternatively, a property is ascribed to a thing that could not possibly have that property. An example is a person learning that the game of cricket involves team spirit, and after being given a demonstration of each player's role, asking which player performs the "team spirit".

History
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 argues that it is 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.

The phrase is introduced in the first chapter. The first example is of a visitor to Oxford. The visitor, upon viewing the colleges and library, reportedly inquires, "But where is the University?" The visitor's mistake is presuming that a University is part of the category "units of physical infrastructure," rather than that of an "institution". Ryle's second example is of a child witnessing the march-past of a division of soldiers. 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.