The Problem of universals is an ancient problem about what is signified by common nouns and adjectives, such as 'man' and 'animal', 'white' and other universals. In Metaphysics, a universal is what particular things have in common namely characteristics or qualities These words apply to many different objects. For example, the word 'human' applies to John, Mary, Poppy. These objects all have something in common (they are all human). The question then arises as to the logical and existential status of the thing that these objects have in common. Is it a thing at all? Is it a concept, or is it something existing in reality, external to the mind? If it exists in reality, is it something physical or something abstract? Is it separated from material objects, or something that, although it remains single and individual, is also a part of each of the objects named by the noun corresponding to it. The problem is of the very deepest, requires extensive investigation, and has never been satisfactorily resolved.
The problem was introduced by Heraclitus, who said that we never step into the same river twice. Heraclitus of Ephesus ( Ancient Greek: &mdash grc-Latn ''Hērákleitos ho Ephésios'' English Heraclitus the Ephesian) (ca In the time it takes us to move our rear foot forward for that second step, water has continued to rush forward, the banks have shifted a bit, and the river is no longer the same. A pupil of Heraclitus, Cratylus, offered a strengthened version of the dictum, claiming that we never step into the same river once. Cratylus ( ancient Greek:, Kratylos) was an ancient Athenian Philosopher from late 5th century BC mostly known through his portrayal 
Heraclitus is sometimes interpreted as implying a skeptical conclusion: since nothing ever stays the same from moment to moment, any information we may think we have is obsolete even as we acquire it, and therefore we can have no certain knowledge of our world. In ordinary usage skepticism or scepticism ( Greek 'σκέπτομαι' skeptomai, to look about to consider see also spelling differences He might also have been suggesting that names are a means to impose stability on the flux of reality—for example by calling some flowing water (or rather, this thing in front of me) a river I pretend that a thing I sense in my environment endures, that this is just one thing of a certain type. In Mathematics, Logic and Computer science, type theory is any of several Formal systems that can serve as alternatives to Naive set theory This would make of him the first nominalist. Nominalism is a metaphysical view in Philosophy according to which general or abstract terms and predicates exist but that either universals
The metaphysics of Plato may be partly understood as an answer to Heraclitus, especially to the skeptical implications of his writings. Metaphysics is the branch of Philosophy investigating principles of reality transcending those of any particular science Biography Early life Birth and family Plato was born in Athens Greece For Plato, our intellect can contemplate the same river any number of times, for river as a form or type of thing, is changeless and eternal, and thus we can always have the idea of that form. Plato, at least during the first part of his life, believed there to be a sharp distinction between the world of sensible objects and the world of the Forms: one can only have opinions about the former, but one can have knowledge about the latter. Plato 's Theory of Forms asserts that Forms (or Ideas) and not the material world of change known to us through sensation, possess Knowledge is defined ( Oxford English Dictionary) variously as (i expertise and skills acquired by a person through experience or education the theoretical or practical understanding For Plato it was not possible to have knowledge of anything that could change, since knowledge had to be forever unfailing. For that reason, the world of the Forms is the real world, like sunlight, the sensible world is only imperfectly or partially real, like shadows. Plato 's Theory of Forms asserts that Forms (or Ideas) and not the material world of change known to us through sensation, possess The Allegory of the Cave is an Allegory used by the Greek Philosopher Plato in his work The Republic. The Allegory of the Cave is an Allegory used by the Greek Philosopher Plato in his work The Republic.
It must be noted that the Platonic notion of changeless ideals isn't confined to universals. Particular terms, too, can be understood as the name of an intelligible form. So although river is a form, Meander is also a form, and "the Meander as it was at noon last Friday" is a form. Even the concept "Heraclitean flux" is a form, and as such fluxlessly timeless. There are many puzzles here, and Plato himself explored several of them in his dialogue Parmenides. Parmenides is one of the Dialogues of Plato. It is perhaps Plato 's most challenging dialogue
But at least part of what Plato meant to convey is that river is a timeless ideal in which physical rivers partially participate, as the material world is an imperfect mirror of the really real world. Plato, accordingly, took a realist position regarding universals. Contemporary philosophical realism is the belief in a Reality that is completely Ontologically independent of our conceptual schemes linguistic practices beliefs This Platonic realism, however, in denying full reality to the material world, differs sharply with modern forms of realism, which generally assert the reality of the external, physical world and which in some versions deny the reality of ideals. Platonic realism is a philosophical term usually used to refer to the idea of realism regarding the existence of universals after the Greek Contemporary philosophical realism is the belief in a Reality that is completely Ontologically independent of our conceptual schemes linguistic practices beliefs
Plato's student Aristotle disagreed with both Plato and Heraclitus. Aristotle (Greek Aristotélēs) (384 BC – 322 BC was a Greek philosopher a student of Plato and teacher of Alexander the Great. Aristotle transformed Plato's forms into "formal causes," the blueprints or essences of individual things. In Philosophy, essence is the attribute or set of attributes that make an object or substance what it fundamentally is and which it has by necessity Where Plato idealized geometry, Aristotle emphasized biology and related disciplines, so much of his thinking concerns living beings and their properties. Geometry ( Greek γεωμετρία; geo = earth metria = measure is a part of Mathematics concerned with questions of size shape and relative position Foundations of modern biology There are five unifying principles The nature of universals in Aristotle's philosophy therefore hinges on his view of natural kinds. In Philosophy a natural kind is a grouping of things which is a natural grouping not an artificial one
Consider for example a particular oak tree. The term oak can be used as part of the common name of any of about 400 species of Trees and Shrubs in the Genus Quercus (from Latin This is a member of a species, and it has much in common with other oak trees, past, present, and future. Its universal, its oakness, is a part of it. A biologist can study oak trees and learn about oakness and more generally the intelligible order within the sensible world. Accordingly, Aristotle was more confident than either Heraclitus or Plato about coming to know the sensible world; he is an early empiricist. In Philosophy, empiricism is a theory of Knowledge which asserts that knowledge arises from Experience. Aristotle was a new sort of realist about universals; some might call this view moderate realism. Moderate realism as a position in the debate on the Metaphysics of universals holds that there is no realm in which universals exist (against Platonism,
The problem was introduced to the medieval world by Boethius, by his translation of Porphyry's Isagoge. Anicius Manlius Severinus Boethius (480&ndash524 or 525 was a Christian philosopher of the 6th century The Isagoge or "Introduction" to Aristotle's "Categories", written by Porphyry in Greek and translated into Latin by Boethius It begins
For the moment, I shall naturally decline to say, concerning genera and species, whether they subsist, whether they are bare, pure isolated conceptions, whether, if subsistent, they are corporeal or incorporeal, or whether they are separated from or in sensible objects, and other related matters. This sort of problem is of the very deepest, and requires more extensive investigation.
This intrigued medieval philosophers such as Abelard, who wrote an extensive commentary on the Isagoge.
As the Middle Ages waned and the Renaissance approached, some European intellectuals switched their allegiance to nominalism. The Renaissance (from French Renaissance, meaning "rebirth" Italian: Rinascimento, from re- "again" and nascere The new Heraclitus of this period was William of Ockham. William of Ockham (also Occam, Hockham, or any of several other spellings ˈɒkəm (c "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 disbelieved in 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 Socrates. Nothing further is explained by saying that. This is in accord with the analytical method which has since come to be called Ockham's razor, the principle that the explanation of any phenomenon should make as few assumptions as possible. Occam's razor (sometimes spelled Ockham's razor) is a principle attributed to the 14th-century English Logician and Franciscan Friar,
A position subsequently identified as conceptualism was formulated by Pierre Abelard. Conceptualism is a Doctrine in Philosophy intermediate between Nominalism and realism that says universals exist only within the This advertises itself as a middle way between nominalism and realism. There is something in common between like individuals, but it is a concept in the mind, not an objective reality.
Critics argue that conceptualist approaches like Abelard's only answer 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. If resemblances between individuals are asserted, conceptualism becomes moderate realism; if they are denied, it collapses into nominalism. Moderate realism as a position in the debate on the Metaphysics of universals holds that there is no realm in which universals exist (against Platonism, Nominalism is a metaphysical view in Philosophy according to which general or abstract terms and predicates exist but that either universals 
George Berkeley, best known for his empiricism, was also an advocate of an extreme nominalism. George Berkeley (ˈbɑrkli (12 March 1685 14 January 1753 also known as Bishop Berkeley, was a Philosopher. In Philosophy, empiricism is a theory of Knowledge which asserts that knowledge arises from Experience. Nominalism is a metaphysical view in Philosophy according to which general or abstract terms and predicates exist but that either universals Indeed, he disbelieved even in the possibility of a general thought as a psychological fact. It is impossible to imagine a man, the argument goes, unless one has in mind a very specific picture of one who is either tall or short, European or Asian, blue-eyed or brown-eyed, etc. When one thinks of a triangle, likewise, it is always obtuse, or right-angled, or acute. A triangle is one of the basic Shapes of Geometry: a Polygon with three corners or vertices and three sides or edges which are Line There is no mental image of a triangle in general. Not only, then, do general terms fail to correspond to extra-mental realities, they don't correspond to thoughts either.
Berkeleyan nominalism contributed to the same thinker's critique of the possibility of matter. In the climate of English thought in the period following Isaac Newton's great contributions to physics, there was much discussion of a distinction between primary qualities and secondary qualities. Sir Isaac Newton, FRS (ˈnjuːtən 4 January 1643 31 March 1727) Biography Early years See also Isaac Newton's early life and achievements The primary/secondary quality distinction is a conceptual distinction in Epistemology and Metaphysics, concerning the nature of Reality. The primary qualities were supposed to be true of material objects in themselves (size, position, momentum) whereas the secondary qualities were supposed to be more subjective (color and sound). In Classical mechanics, momentum ( pl momenta SI unit kg · m/s, or equivalently N · s) is the product Sound' is Vibration transmitted through a Solid, Liquid, or Gas; particularly sound means those vibrations composed of Frequencies But on Berkeley's view, just as it is meaningless to speak of triangularity in general aside from specific figures, so it is meaningless to speak of mass in motion without knowing the color. If the color is in the eye of the beholder, so is the mass.
John Stuart Mill discussed the problem of universals in the course of a book that eviscerated the philosophy of Sir William Hamilton. John Stuart Mill (20 May 1806 &ndash 8 May 1873 British Philosopher, political economist, civil servant and Member of Parliament, was an influential Sir William Hamilton 9th Baronet ( 8 March 1788 &ndash 6 May 1856) was a Scottish metaphysician. Mill wrote, "The formation of a Concept does not consist in separating the attributes which are said to compose it from all other attributes of the same object, and enabling us to conceive those attributes, disjoined from any others. We neither conceive them, nor think them, nor cognize them in any way, as a thing apart, but solely as forming, in combination with numerous other attributes, the idea of an individual object. "
At this point in his discussion he seems to be siding with Berkeley. But he proceeds to concede under some verbal camouflage, that Berkeley's position is impossible, and that every human mind performs the trick Berkeley thought impossible.
"But, though meaning them only as part of a larger agglomeration, we have the power of fixing our attention on them, to the neglect of the other attributes with which we think them combined. While the concentration of attention lasts, if it is sufficiently intense, we may be temporarily unconscious of any of the other attributes, and may really, for a brief interval, have nothing present to our mind but the attributes constituent of the concept. "
In other words, we may be "temporarily unconscious" of whether an image is white, black, or yellow and concentrate our attention on the fact that it is a man, and on just those attributes necessary to identify it as a man (but not as any particular one). It may, then, have the significance of a universal of manhood.
The 19th century American logician Charles Peirce developed his own views on the problem of universals in the course of a review of an edition of the writings of George Berkeley. The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar Charles Sanders Peirce (pronounced purse) (September 10 1839 &ndash April 19 1914 was an American Logician mathematician, philosopher Peirce begins with the observation that "Berkeley's metaphysical theories have at first sight an air of paradox and levity very unbecoming to a bishop. Metaphysics is the branch of Philosophy investigating principles of reality transcending those of any particular science " He includes among these paradoxical doctrines Berkeley's denial of "the possibility of forming the simplest general conception. " Peirce responded to this paradox in the way that one might expect from a man known as the father of pragmatism. Pragmatism generally considered to have originated in the late nineteenth century with Charles Peirce, who first stated the Pragmatic maxim. He wrote that if there is some mental fact that works in practice the way that a universal would, that fact is a universal. "If I have learned a formula in gibberish which in any way jogs my memory so as to enable me in each single case to act as though I had a general idea, what possible utility is there in distinguishing between such a gibberish . . . and an idea?" Peirce also held as a matter of ontology that what he called "thirdness," the more general facts about the world, are extra-mental realities.
William James learned pragmatism, this way of understanding an idea by its practical effects, from his friend Peirce, but he gave it new significance. For other people named William James see William James (disambiguation William James (January 11 1842 – August 26 1910 was a pioneering (Too new for Peirce's taste -- he came to complain that James had "kidnapped" the term, and to call himself a "pragmaticist" instead. ) Although James certainly agreed with Peirce and against Berkeley that general ideas exist as a psychological fact, he was a nominalist in his ontology. "From every point of view," he wrote, "the overwhelming and portentous character ascribed to universal conceptions is surprising. Why, from Plato and Aristotle, philosophers should have vied with each other in scorn of the knowledge of the particular, and in adoration of that of the general, is hard to understand, seeing that the more adorable knowledge ought to be that of the more adorable things, and that the things of worth are all concretes and singulars. The only value of universal characters is that they help us, by reasoning, to know new truths about individual things. The meaning of the word truth extends from Honesty, Good faith, and Sincerity in general to agreement with Fact or Reality "
There are at least three ways in which a realist might try to answer James' challenge of explaining the reason why universal conceptions are more lofty than those of particulars -- there is the moral/political answer, the mathematical/scientific answer, and the anti-paradoxical answer. Each has contemporary or near contemporary advocates.
In 1948 Richard M. Weaver, a conservative political philosopher, wrote Ideas Have Consequences, a book in which he diagnosed what he believed had gone wrong with the modern world, leading indeed to the two world wars that dominated the first half of the 20th century. Year 1948 ( MCMXLVIII) was a Leap year starting on Thursday (link will display the 1948 calendar of the Gregorian calendar. Richard Malcolm Weaver Jr ( March 3, 1910 – April 1, 1963) was an American scholar who taught English at the Ideas Have Consequences is a philosophical work by Richard M Weaver, published in 1948. The problem was, in his words, "the fateful doctrine of nominalism. "
Western civilization, Weaver wrote, succumbed to a powerful temptation in the 14th century, the time of William of Ockham, and has paid dearly for it since. "The defeat of logical realism in the great medieval debate was the crucial event in the history of Western culture; from this flowed those acts which issue now in modern decadence. "
Roger Penrose contends that the foundations of mathematics can't be understood absent the Platonic view that "mathematical truth is absolute, external, and eternal, and not based on man-made criteria . Sir Roger Penrose, PhD, OM, FRS (born 8 August 1931) is an English Mathematical physicist and Emeritus The philosophy of mathematics is the branch of Philosophy that studies the philosophical assumptions foundations and implications of Mathematics. . . mathematical objects have a timeless existence of their own. . . . "
Nino Cocchiarella, professor emeritus of philosophy at Indiana University, has maintained that conceptual realism is the best response to certain logical paradoxes to which nominalism leads. Nino Cocchiarella (born 1933 Professor Emeritus of Philosophy at Indiana University, is best known for his work in Formal logic and Ontology. Indiana University is the flagship campus of the Indiana University system. This is the argument, for example, of his paper "Logical Atomism, Nominalism, and Modal Logic," Synthese (June 1975). Year 1975 ( MCMLXXV) was a Common year starting on Wednesday (link will display full calendar of the Gregorian calendar. Note that in a sense Professor Cocchiarella has adopted platonism for anti-platonic reasons. Plato, as one sees in the dialogue Parmenides, was willing to accept a certain amount of paradox with his forms. Cocchiarella adopts the forms to avoid paradox.