In The Concept of Mind (1949), Ryle admits to having been
taken in by the body-mind dualism which permeates Western
philosophy, and claims that the idea of mind as an independent
entity, inhabiting and governing the body, should be rejected as a
redundant piece of literalism carried over from the era before the
biological sciences became established. The proper function of
mind-body language, he suggests, is to describe how higher organisms
such as humans demonstrate resourcefulness, strategy, the ability to
abstract and hypothesize and so on from the evidences of their
He attacks the idea of 17th and 18th century thinkers (such
as Descartes) that nature is a complex machine, and that human
nature is a smaller machine with a "ghost" in it to account for
intelligence, spontaneity, and other such human qualities. While
mental vocabulary plays an important role in describing and
explaining human behaviour, neither are humans analogous to machines
nor do philosophers need a "hidden" principle to explain their
Ryle asserted that the workings of the mind are not distinct
from the actions of the body. They are one and the same. Mental
vocabulary is, he insists, merely a different manner of describing
action. He also claimed that the nature of a person's motives is
defined by that person's dispositions to act in certain situations.
There are no overt feelings, pains, or twinges of vanity. There is
instead a set of actions and feelings that are subsumed under a
general behaviour-trend or propensity to act, which we term
Novelists, historians and journalists, Ryle points out, have
no trouble in ascribing motives, moral values and individuality to
people's actions. It is only when philosophers try to attribute
these qualities to a separate realm of mind or soul that the problem
arises. Ryle also created the classic argument against cognitivist
theories of explanation, Ryle's Regress.
One theme of The Concept of Mind is that dualism involves
category mistakes and philosophical nonsense. Category mistakes and
nonsense as philosophical topics continued to inform Ryle's work.
Students in his 1967-8 Oxford audience would be asked rhetorically
what was wrong with saying that there are three things in a field:
two cows and a pair of cows. They were also invited to ponder
whether the bung-hole of a beer barrel is part of the barrel or not.
A category mistake, or category error, 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 the metaphor "time
crawled", which if taken literally is not just false but a category
mistake. 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.
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.
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 inquired “But where is the University?" 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 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.'
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. In the philosophy of the mind, Ryle's
category mistake argument can be used to support eliminative
materialism. By using the argument, one can attack the existence of
a separate, distinct mind. The argument concludes that minds are not
conscious, but a collective predicate for a set of observable
behaviour and unobservable dispositions.