"One of the most debated problems during the Middle Ages was the problem of the nature of general concepts. Greek logic, after long
discussions, established the theory of the concept, which became classic, and was transmitted by commentators in their manuals and compendia. In the Middle
Ages, the problem of the nature of general concepts, called by the logicians of the time universalia, was placed in the centre of logical and
philosophical concerns, and gave rise to the famous "dispute of the universals".
This dispute lasted throughout the Middle Ages, though in certain periods a particular conception might prevail. This problem originates from
a famous passage in Porphyry's Introduction to Aristotle's Categories -- Isagogé -- translated by Boethius, a treatise which represented the
corner-stone of all dialectical studies. This passage appears at the beginning of the above mentioned work and it raised the following problem: are genera and
species real, or are they empty inventions of the intellect? Here is that famous passage, opening the Prooemium in Porphyry's Isagogé: De
generibus speciebus illud quidem sive subsistent, sine in nudis intellectibus posita sunt, sive subsistentia corporalia sent an incorporalia, et utrum separata
a sensibilibus an in sensibilibus posita et circa ea constantia, dicere recusabo; altissimum mysterium est hujus modi et majoris indigens inquisitionis
("I shall avoid investigating whether genera and species do exist in themselves, or as mere notions of the intellect, or whether they have a corporeal, or
incorporeal existence, or whether they have an existence separated from sensible things, or only in sensible things; it is quite a mystery which requires a
more thorough investigation than the present one"). This problem, raised by Boethius, had been left aside for a while in the Middle Ages, but it arose again as
soon as Aristotle's texts became better known.
Let us now see how this extraordinary problem of the universals arose. Aristotle said, (...) that there was no other science but of the
universal. This thesis was adopted by the Scholastic logicians, who kept repeating: Scientia est de universalibus, existentia est singularium --
"Science concerns the universals, existence refers to singular (objects)" or, with another formula: Nulla est fluxorum scientia -- "There is no
science of transient (ephemeral) things". It is therefore clear that the universal will be the central problem of any science, its whole foundation, its
starting point. They granted such a great importance to this problem because they wanted first and foremost to lay the basis of science, without which science
itself could not exist. Also, at the beginning of this dispute, a nominalist thinker, Roscelin, appeared, who denied the universal; this shocked the
Aristotelian and Latin minded Middle Ages and gave rise to the discussion.
The treatises on the history of philosophy simplify, generally, the solutions the Scholastic proposed to the problem of the universals, and
deal with only three or four main solutions. This simplification is made in order to detect the general directions of the Scholastics' thinking. As we shall
see, the problem was far more complicated and subtle. Of course, it appeared simple to the first Scholastics. F. J. Thonnard remarks (Précis d'histoire de
la philosophie, Paris, Tournai, Rome, 1963 p. 285) : "In the Middle Ages, the first philosophers did not realise initially all the nuances, and they
answer by yes, or by no". According to Thonnard, only two groups of philosophers should be considered: (1) the realists, embracing a metaphysical point of
view, and who assert that the universals are definitely objects; (2) the antirealists, adopting a psychological standpoint, and raising objections which force
the realists to be more precise in their solutions.
The problem of the universals, as defined by Porphyry, and taken over by Boethius, was called prima quaestio -- "the first problem".
Great importance was attached to this problem because of the numerous trends and nuances implied by the solutions. We possess a complete classification of
these solutions, made by a mediaeval logician, John of Salisbury (twelfth century), in his. work Metalogicus (Metalogicon). In this work, the author
enumerates 13 directions in the problem of the universals.
Metalogicus was a treatise on logic which the author himself confessed to have written (1159) from memory, after a rather long
interruption of his studies of logic. His intention was to prove the usefulness of logic, opposing the attacks against this discipline by certain philosophers.
The value of the work is that it is a vast source of information about the conceptions of the time.
Here are the 13 conceptions in the problem of the universals, such as given by John of Salisbury.
1) Roscelin's conception, in keeping with which the universals are mere words -- votes (nominalism).
2) Abelard's, and his disciples' conception, with whom the general concepts are reduced to sermons, predication being possible only in
sermo (judgement), as the predicate of an object cannot be an object.
3) Another position upheld that the universal is intellectus (idea), or notio, such as Cicero (that is the Stoics) had
seen it. Thinking cannot discriminate the particular and corporeal concrete from the sensation, but only the abstract, namely the general abstract, which is
devoid of reality.
4) Walter of Mortaigne's position, who maintained the universals to be closely united with the individuals (res sensibiles), but to
have a mode of existence -- status -- according to which way they are considered. It is the so-called theory of the status.
Walter of Mortaigne was a professor in Paris, and died as a bishop of Laon in 1174. His position is interesting because he professed,
basically, a multiplicity of ontological status. The species and genera, up to the supreme genus, have different existential states.
So, the status of the general, united to the individual, depends on the consideration of the individual as belonging to one or to another species. (This idea,
of "the multiple states of the Being" originated with Aristotle. See the relevant chapter). The idea of multiple ontological states has appeared in
contemporary logic since the establishment of the many-valued logics where the proposition can have more than two values, truth and falsehood. A close
examination of Walter of Mortaigne's theories in this respect would certainly prove very interesting.
5) The platonic realism of Bernard of Chartres.
6) Gilbert of Poitiers' conception concerning the native forms - forma nativae.
Gilbert de la Porrée, bishop of Poitiers (1076-1154), is known also as Gilbertus Porretanus, or Pictaviensis (of Poitiers). His most
important work on logic is De sex principiis, which played an important part later on. He started from the Platonic conception of ideas -- principles;
these have copies -- the native forms -- which become multiple ant distinct in the individuals. Comparing these forms, the intellect shapes by abstraction a
unique form, the genus, or the species, which conforms with the divine idea. Therefore in Plato's existence he saw a special "subsistence"subsistentia
-- the essence of the individual Plato, this "Platonicity" -- Platonitas --, his distinct form, a copy of the idea of man.
7) Gauslenus of Soissons' opinion, according to which the universal exist only in collections.
Gauslenus of Soissons (1125-1151), bishop of Soissons, held that the universal concept exists only in the collection of individuals
belonging to the same class, and not in the individual. The author of the treatise Metalogicus wrote that "Gauslenus Suessonensis episcopus situated
the universal in objects gathered in a collection" (rebus in unum collectis) and denied it with isolated individuals.
8) The so-called theory of "manners" -- maneries.
This conception, just like that of Gauslenus of Soissons, of the collections or of native forms, is to be found in a work, written in the
Middle Ages, De generibus et speciebus. This conception is a nominalist variant, in keeping with which the thing -- res -- is mere word --
The term maneries means "way of treating" or "way of handling", and is the origin of the French "manière". The canonist Huguccio
(d. 1212), author of Summa Decretorum defined, in this sense, the species (species) as being rerum maneries (the "manner" of
things). In short, a thing is a word -- vox --, and genus is its manner -- maneries.
9) The opinion according to which the universals are abstract form similar to the mathematical forms.
10) The so-called ratio indifferentiae doctrine, in keeping with which one thing can be at the same time individual and universal,
although there is nothing universal in things, but the universal is what is similar between them.
Charles de Rémusat in Abélard (2nd ed., Paris, 1855) supplied a few excerpts from Abelard Glossulae super Porphyrium which
explain this ratio indifferentiae conception. What in Plato, or in Socrates, is non-differentiated, or similar, indifferens vel consimile.
Certain things are mutually convening, or agreeing, that is similar in nature, such as animals, bodies, so they are both universal and particular -- universal
in that they are several in a community of essential attribution, and particular in that each of them is different from the other.
11) William of Champeaux's (1070-1120) opinion, who held a rather strange realism, finally coming to a theoria indifferentiae.
12) The conception according to which the distinction between genus and individual lies merely in a particularity of existence, as
the universal exists at the same time in several and in the particular object.
13) The conception of the unknown author of the above mentioned -- De generibus et speciebus, a sort of Platonism, the "theory of
identity". According to it, the genus, mankind for instance, is unique and identical with all the individuals, which are only accidentally distinct." (pp.
From: Anton Dumitriu, History of Logic, Vol. II, Tunbridge Wells: Abacus Press 1977.