Ancient Greek philosophy Plato was perhaps the first writer in
Western philosophy to clearly state a
realist, i.e., non-nominalist, position: ... We customarily hypothesize a single form in connection with each of the many things to which we apply the same name. ... For example, there are many beds and tables. ... But there are only two forms of such furniture, one of the bed and one of the table. (
Republic 596a–b, trans. Grube) What about someone who believes in beautiful things, but doesn't believe in the beautiful itself ...? Don't you think he is living in a dream rather than a wakened state? (
Republic 476c) The Platonic universals corresponding to the names "bed" and "beautiful" were the
Form of the Bed and the Form of the Beautiful, or the
Bed Itself and the
Beautiful Itself. Platonic Forms were the first universals posited as such in philosophy. Our term "universal" is due to the English translation of
Aristotle's technical term
katholou which he coined specially for the purpose of discussing the problem of universals.
Katholou is a contraction of the phrase
kata holou, meaning "on the whole". Aristotle famously rejected certain aspects of Plato's Theory of Forms, but he clearly rejected nominalism as well: ... 'Man', and indeed every general predicate, signifies not an individual, but some quality, or quantity or relation, or something of that sort. (
Sophistical Refutations xxii, 178b37, trans. Pickard-Cambridge) The first philosophers to explicitly describe nominalist arguments were the
Stoics, especially
Chrysippus.
Medieval philosophy In
medieval philosophy, the French philosopher and
theologian Roscellinus (c. 1050 – c. 1125) was an early, prominent proponent of nominalism. Nominalist ideas can be found in the work of
Peter Abelard and reached their flowering in
William of Ockham, who was the most influential and thorough nominalist. Abelard's and Ockham's version of nominalism is sometimes called
conceptualism, which presents itself as a middle way between nominalism and realism, asserting that there
is something in common among like individuals, but that it is a concept in the mind, rather than a real entity existing independently of the mind. Ockham argued that only individuals existed and that universals were only mental ways of referring to sets of individuals. "I maintain", he wrote, "that a universal is not something real that exists in a subject ... but that it has a being only as a thought-object in the mind [objectivum in anima]". As a general rule, Ockham argued against assuming any entities that were not necessary for explanations. Accordingly, he wrote, there is no reason to believe that there is an entity called "humanity" that resides inside, say, Socrates, and nothing further is explained by making this claim. This is in accord with the analytical method that has since come to be called
Ockham's razor, the principle that the explanation of any phenomenon should make as few assumptions as possible. Critics argue that conceptualist approaches answer only the psychological question of universals. If the same concept is
correctly and non-arbitrarily applied to two individuals, there must be some resemblance or shared property between the two individuals that justifies their falling under the same concept and that is just the metaphysical problem that universals were brought in to address, the starting-point of the whole problem (MacLeod & Rubenstein, 2006, §3d). If resemblances between individuals are asserted, conceptualism becomes moderate realism; if they are denied, it collapses into nominalism.
Modern and contemporary philosophy In
modern philosophy, nominalism was revived by
Thomas Hobbes and
Pierre Gassendi. In
contemporary analytic philosophy, it has been defended by
Rudolf Carnap,
Nelson Goodman,
H. H. Price, Lately, some scholars have been questioning what kind of influences nominalism might have had in the conception of
modernity and contemporaneity. According to
Michael Allen Gillespie, nominalism profoundly influences these two periods. Even though modernity and contemporaneity are secular eras, their roots are firmly established in the sacred. Furthermore, "Nominalism turned this world on its head," he argues. "For the nominalists, all real being was individual or particular and universals were thus mere fictions."
Indian philosophy Indian philosophy encompasses various realist and nominalist traditions. Certain orthodox Hindu schools defend the realist position, notably
Purva Mimamsa,
Nyaya and
Vaisheshika, maintaining that the referent of the word is both the individual object perceived by the subject of knowledge and the universal class to which the thing belongs. According to Indian realism, both the individual and the universal exist objectively, with the second underlying the former. Buddhists take the nominalist position, especially those of the
Sautrāntika and
Yogācāra schools; they were of the opinion that words have as referent not true objects, but only concepts produced in the intellect. These concepts are not real since they do not have efficient existence, that is, causal powers. Words, as linguistic conventions, are useful to thought and discourse, but even so, it should not be accepted that words apprehend reality as it is.
Dignāga formulated a nominalist theory of meaning called
apohavada, or
theory of exclusions. The theory seeks to explain how it is possible for words to refer to classes of objects even if no such class has an objective existence. Dignāga's thesis is that classes do not refer to positive qualities that their members share in common. On the contrary, universal classes are exclusions (
apoha). As such, the "cow" class, for example, is composed of all exclusions common to individual cows: they are all non-horse, non-elephant, etc. ==The problem of universals==