## 1. Issues




Philosophers speak about categories in many different ways. There is
one initial, and rather substantial, difference between philosophers
who allow a very large number of categories and those who allow only a
very small number. The first include among categories such different
things as human, green, animal, thought, and justice; the second speak
only of very general things such as substance, quality, relation, and
the like, as categories. Among twentieth-century authors who allow
many categories is Gilbert Ryle (b. 1900, d. 1976). Roderick Chisholm
(b. 1916, d. 1999) is an example of those who have only very
few. Medieval authors follow Aristotle's narrow
understanding.




The disagreement concerning categories in the history of philosophy
does not end there. Even if we restrict the discussion to a small
number of items of the sort that Aristotle regards as categories, many
issues remain to be settled about them, and philosophers frequently
disagree about how to settle them. These issues may be gathered into
roughly ten groups.




The first group comprises what may be described roughly as extensional
issues; they have to do with the number of categories. The extension
of a term is comprised by the things of which the term can be
truthfully predicated. Thus the extension of 'cat'
consists of all the animals of which it is true to say that they are
cats. Philosophers in general frequently disagree on how many
categories there are. For example, Aristotle lists up to ten, but
gives the impression that the ultimate number is not settled at
all. Plotinus (204/5-270) and Baruch Spinoza (1632-77)
reduce the number radically, but their views do not by any means
establish themselves as definitive. In the Middle Ages the number of
categories is always small (ten or less) but it nonetheless
varies.




The second group is roughly intensional; they concern what categories
are and the properties they have. The intension of a term is the set
of properties that apply to the things of which the term is truthfully
predicated and which are listed in its definition or taken to be
implied by it. Thus the intension of 'human' is, say,
rational animal, and includes living and corporeal. Again,
philosophers disagree as to whether categories can be defined, and if
they can be, how they are to be defined. In general, medieval authors
reject the possibility of defining them for various reasons. One
reason is that most of these authors conceive categories as divisions
of being, and being for them is not a genus. Since a definition
requires a genus ("animal" in the definition of
"human" given earlier), the categories cannot be defined.
Another reason is that a definition requires a difference that
distinguishes what is being defined from other types of thing within
the genus ("rationality" for humans, within the genus
"animal"), but the categories are the highest kind of
things, so there is nothing outside of them that can be used to
distinguish them.




The third group is ontological; the issues here involve the place that
categories occupy in the map of all things that exist or can
exist. Ontology is the sub-discipline of philosophy that deals with
being and what exists. The three most common questions raised in this
context are: (1) Are categories extra-mental entities, such as
properties, qualities, relations, structures, sets, classes, or forms?
(2) Are categories intra-mental entities, such as phenomena, mental
acts, mental contents, *Gestalten*, or mental structures? (3)
Are categories linguistic entities, such as meanings, words, types,
tokens, predicates, or syntactical places? Four views stand out.
According to one, categories are linguistic entities-call them
words-such as the words 'quality' and
'relation,' with which we speak about things. According to
another, categories are mental acts-call them
concepts-such as the concept of quality or the concept of
relation, with which we think about things. Categories are also
thought to be extra-mental features that things about which we think
and speak have-call them properties-such as the properties
of being a quality or of being a relation. Finally, there is an
inclusive view that tries to integrate all of these three positions
into one, arguing that categories are words, concepts, and properties
but in different ways. These four views are not the only choices
available (see Gracia 1999), but they are the most popular views
considered in the Middle Ages.




The fourth group has to do with causes; they include questions about
how categories are established or brought about. These issues have
attracted considerable attention in recent years, particularly among
post-modern philosophers, such as Michel Foucault (1926-84). In
the Middle Ages the way this question is posed depends heavily on the
ontological status accorded to categories, particularly on whether
they are mental or extra-mental entities. The Foucauldian concern with
"social construction," however, seems to be absent from
medieval discussions.




The fifth group involves epistemology; they concern primarily how we
have access to categories, that is, how we get to know them and under
what conditions. Although this is not a widespread topic of discussion
in the Early Middle Ages, later on there are various attempts to
determine the number and identity of the categories and the basis on
which this determination can be carried out. These attempts, and the
assumptions which guide them, are closely related to an important
issue for the Middle Ages in general that becomes critical toward its
end: the relation of language, thought, and reality, or as it is also
put, between signifying, thinking, and being, or between words,
concepts, and things. Some think the relation is isomorphic, whereas
others disagree.




The sixth group concerns language; they involve the terms used to talk
about categories and the way they function. These issues are
particularly relevant for the view that considers categories to be
linguistic entities, and therefore become central in twentieth-century
Anglo-American philosophy. In the Middle Ages, they are especially
important in the latter part of the period when issues of language
take center stage in philosophical discussions.




The seventh group falls within the philosophy of mind; they have to do
with the status of categories in the mind. Since we think about
categories and through categories, it is pertinent for a philosopher
to ask questions of this sort. This topic is particularly pertinent
for those who think that categories are mental entities. In the
Middle Ages, the questions raised about the status of categories in
the mind are put generally in the context of other topics, such as the
status of universals, but much of what medieval authors say about
universals can be applied, *mutatis mutandis,* to
categories.




The eighth group may be characterized as social, political, and
axiological; they have to do with the value and use of categories by
persons, society, and the polity. Many contemporary philosophers have
found in this topic a way of undermining some traditional views of the
world that they consider oppressive or inaccurate. These issues do not
seem to be explicitly raised in the Middle Ages and may indicate one
important difference between medieval and contemporary philosophical
thought.




The ninth group is meta-disciplinary; they involve the discipline that
studies categories. Obviously, how these issues are addressed depends
to a great extent on the position one takes concerning the conception
and ontological status of categories, as well as on how the various
disciplines of learning are understood. This is a topic of concern in
the Middle Ages, and is explicitly addressed by late medieval
authors. They identify various disciplines as the place to study
categories, ranging from grammar and logic to metaphysics.




Finally, rather than discussing categories in general, one may deal
with particular categories, such as substance or relation. This is
perhaps the most frequent way in which categories are discussed in the
history of philosophy, including the Middle Ages.




Apart from these topics, there are others that are closely related to
categories and often discussed together with them. One involves
trans-categorial terms, such as 'being,'
'one,' 'true,' and 'good,' which
apply to all categories and are predicable of every term that falls
within the categories. In the Middle Ages, these are known as
"the transcendentals" and their status becomes
controversial in the thirteenth century (see Gracia 1992b).




A second topic concerns what are known as
"ante-predicaments," and are introduced by Aristotle at
the beginning of *Categories*: univocity, equivocity, and
denomination. Univocity occurs when the same term is predicated in the
same sense, as 'animal' is of a man and an ox. Equivocity
is dived into random equivocity and purposeful equivocity. The former
occurs when the same term is predicated in different senses, as
'animal' is of a person and a picture of a person. The
latter involves the broader issues of analogical predication.And
denomination occurs when the predicated term is derived from another,
as 'grammarian' is from 'grammar' (see
Ashworth 1991).




A third topic involves the "post-predicaments," a cluster
of seemingly disparate notions treated by Aristotle in
*Categories* after he discusses the categories proper. They
include opposites (relatives, contraries, privation and possession,
and affirmation and negation), priority (in time, in existence, in
order, and in value) and simultaneity (in time and by nature), change
(generation and corruption, increase and decrease, alteration and
locomotion), and several meanings of 'having.'




A fourth topic, also commonly discussed beginning in the thirteenth
century, concerns what becomes known as "syncategorematic
terms." These are particles, such as 'every' and
'and,' which are not classifiable into any category (see
William of Sherwood 1968).




A fifth topic of discussion introduced in the Middle Ages through
Boethius' Commentaries on Porphyry's *Isagoge* involves the
"predicables" (*praedicabilia*), which are ways in
which predicates relate to subjects. Examples are
"accident" ('black' in 'This cat is
black'), "species" ('man' in
'Socrates is a man'), and "definition"
('rational animal' in 'Man is a rational
animal') (see Porphyry 1975). Although these issues are
originally introduced by Aristotle in the *Topics*, this work
was not available in the Middle Ages until after the period of
translations in the twelfth century.




Because of considerations of space, we shall not discuss these related
topics here, nor can we refer to all the issues about categories
raised by medieval authors or mentioned above. However, the conceptual
framework of issues we have introduced should help in the
understanding of how categories are approached in the Middle Ages and
the differences between the medieval approach and those taken in other
periods of the history of philosophy. We begin with the classical
background of the discussion of categories in the Middle Ages. This
consists primarily of Aristotle, who is responsible for the first
treatise on categories ever written.


## 2. Classical Background (pre-500 C.E.)




The philosophical discussion of categories begins with Aristotle
(B.C.E. 384-322). His view is difficult to interpret, even though
the texts dealing with this topic (*Categories*, *Topics*
I, and *Metaphysics* V) are characteristically direct
in style. Still, there is some consensus among scholars that Aristotle
proposes three ways of understanding categories: as realities,
concepts, and linguistic terms. Much of the subsequent philosophical
discussion of categories concerns the correctness of this view. Some
favor a position according to which categories are realities, which
are then said to be reflected in thought and language; some endorse a
view of them merely as concepts, which are also said to be reflected
in language; some maintain that categories are merely linguistic
terms, and reject any implication that they are real entities or
concepts; and still others maintain an inclusive view that contends
that categories are all three: words, concepts, and extra-mental
entities.




The Greek term that Aristotle uses for category means predicate
(*categoria*) so that categories would appear to be
kinds of predicates, the most general kinds of predicates. However,
some commentators claim that Aristotle uses the term rather for kinds
of predication and kinds of beings (for example in *Topics*
103b20-27, and *Metaphysics* 1017a22-27; see Frede
1987, 29-48). In *Categories*, Aristotle uses the term
technically to refer to *substance*, *quantity*,
*quality*, *relation*, *place*, *time*,
*position*, *state*, *action*, and
*affection* (9a27, 11b37, 11b7), although he also speaks of
less general terms, such as 'white,' 'half,'
and 'last year,' and trans-categorial terms such as
'good' and 'unity.' Aristotle's
categories are not, strictly speaking, the predicates we use when we
speak in ordinary language; rather, they are the most general kinds of
predicates, or predications. Thus 'white' and
'here' do not refer to categories, but
'quality' and 'place' do. The Aristotelian
categories may be taken as the most general predicates which can be
predicated or, alternatively, they are the most general kinds of
predication into which the predicates we use in ordinary discourse may
be classified. They provide answers to direct questions such as when,
where, how, what, and so on. Terms that extend to more than one
category (e.g., 'good'), or do not apply to categories
(e.g., 'and') are treated separately.




Predicability, then, is not a sufficient condition of categoricity,
but non-predicability is a sufficient disqualification. For Aristotle,
the individual is not, strictly speaking, predicable, although there
are places in which he speaks of the individual as
predicable. Examples of individuals are *this horse* and *a
certain point of grammar present in the knower* (1b5). The first
is what Aristotle calls a *primary substance*, which he defines
in *Categories* as that which is neither predicable of, nor
present in, a subject (2a11). The second is, like a primary substance,
non-predicable, but it can be present in a subject. Both are
individual and neither is predicable.




That Aristotle refers to categories with the Greek term which
corresponds roughly to the term 'predicate' in English
does not mean that he understood categories to be merely linguistic
terms. Indeed, 'predicate' itself is used in a variety of
ways by philosophers. Some think of predicates as properties of some
kind, some as concepts, some as words, and so on. Therefore, to say
that something is a predicate does not necessarily mean that it is a
linguistic term. In the case of Aristotle, there is ample evidence in
*Categories* itself which suggests that categories are not just
linguistic terms that reflect the fundamental ways in which we speak
about things, but also ways in which things are. The interpretative
tradition that favors a linguistic or logical understanding of the
categories goes back at least to Porphyry (1887, 56), who tries to
reconcile what he takes to be Aristotle's linguistic/logical position
with Plato's metaphysics (Ebbesen 1990). Consider for example how
Aristotle introduces the categories: "Of things said without any
combination, each signifies either a substance or quantity or
qualification or a relative or where or when or being-in-a-position or
having or doing or being-affected" (1b25). Clearly, he is
talking about language when he says, "Of things *said*
without combination, each *signifies*...." for
things that are said and that signify are linguistic terms
(*Poetics* 1456b38ff; our emphasis). The linguistic emphasis is
reinforced elsewhere, when he adds that "of things which are
said without any combination none is either true or
false..." (2a9).




At the same time, these statements do not imply that what is signified
necessarily has to be linguistic. Indeed, earlier in
*Categories,* Aristotle unabashedly mixes the language of
"language" with the language of "being" when
he notes: "Of things that *are*: some *are said*
of a subject but *are not* in any subject. For example, man is
said of a subject, the individual man, but is not in any
subject" (1a20; our emphasis). This text begins with a reference
to things that are (*ta onta*), but goes on to speak about
things that are said (*ta legomena*). The same occurs in other
places (2a11). In a text from *Metaphysics* (1017a23-25),
the isomorphism between being and language is openly expressed.




Aristotle is less explicit about the understanding of categories as
concepts. In *Categories* generally he does not speak about how
things are *conceived*; rather, he speaks about how things are
*called* or how they *are*. At the same time, from what
he says elsewhere about signification and the way we think, it is not
unreasonable to surmise that he also thinks of categories as concepts
of some kind. For example, at the beginning of *On
Interpretation*, he claims that "spoken sounds are symbols
of affections [or concepts] in the soul, and written marks symbols of
spoken sounds. And just as written marks are not the same for all men,
neither are spoken sounds. But what these are in the first place
sounds of-affections of the soul-are the same for all; and
what these affections are likenesses of-actual things-are
also the same" (16a 4-8).




None of this, however, is very clear. Indeed, Aristotle never actually
says that categories are words, concepts, or realities; he only speaks
of them as categories, that is, predicates. But
'predicate' can be used to mean realities, concepts, or
linguistic terms. Aristotle does speak of categories *as if*
they were realities or linguistic terms, and one can further infer
that he could have spoken of them *as if* they were
concepts. But this does not definitely clarify what he thinks about
them. Indeed, on the basis of what he says we cannot determine for
sure that he even raises the question of the ultimate ontological
status of categories. The situation is further obscured because
Aristotle never identifies the discipline where categories are
supposed to be studied and he treats them in both logical
(*Categories*, *Topics*) and metaphysical
(*Metaphysics)* contexts.




One more point needs to be made clear. Aristotle never clearly and
consistently ties the categories to sentential or propositional
structure. In *Categories* he appears to consider them in
isolation from their syntactical context, but in *Topics*
(103b20-27) and *Metaphysics* (1017a23-25) he seems
to tie them to predication and, thus, to consider them in relation to
a syntactical context. This ambiguity gives rise to different
interpretations, such as that of Frede, who considers them to be kinds
of predications (1987), and that of Ryle, who views them as
independent from syntactical context (1971). In short, the picture is
far from clear, and this serves to separate Aristotle from authors who
explicitly and exclusively view categories as reflecting syntactical
contexts.




The same ambiguity with respect to the ontological status of
categories that we find in Aristotle is found in many of his medieval
commentators. Perhaps this can be taken as a sign that they believe
categories to be realities, concepts, and linguistic terms, that is,
that categories are ways in which the world is, ways in which we think
about the world, and ways in which we speak about the world. However,
there are some who argue for purely linguistic or conceptual ways of
understanding categories. In modern philosophy, the emphasis shifts
toward the language of thought, a prime example of which is Immanuel
Kant (1724-1804; see Gracia 2000).


## 3. Early Middle Ages (ca. 500-1150)




Long before the Middle Ages, a well-defined tradition of writing
commentaries on philosophical works had been established. It is
perhaps natural, then, that the most common way of engaging philosophy
throughout the Middle Ages consisted in writing commentaries on what
were considered authoritative philosophical texts, and particularly
works by Aristotle. So popular was commentary writing that thousands
of Medieval Latin commentaries on Aristotle's writings are still
extant, of which nearly two hundred concern the *Categories*
(Lohr 1967, 1968, 1970, 1971, 1972, 1973). These commentaries were not
always intended simply to explain texts; often, they became the means
of developing the thoughts of the commentators on various
philosophical topics. Moreover, commentators did not comment on
Aristotle's works in isolation, but also consulted other commentaries
on the same texts. In this way, they engaged and often challenged
other interpretations, and developed their own insights.




At the beginning of the sixth century, we find several late
Neoplatonic philosophers who continue the ancient tradition of
commentary writing. They include Boethius, Philoponus, Elias, David,
pseudo-Elias, Stephanus, and Simplicius. Two of these in particular
deserve mention. Simplicius (490-560) is important because his
Commentary was translated into Latin by William of Moerbeke in 1266
and was subsequently read by Aquinas, Duns Scotus, and Ockham, among
others, though apparently not by Albertus Magnus. In addition,
Simplicius attempted to prove that there are ten and only ten
categories, something that became the subject of dispute in the later
Middle Ages.




Boethius (ca. 480-524/5) is important because he sought to
preserve Greek philosophy by translating all of the works of Plato and
Aristotle into Latin. Unfortunately, his untimely death prevented him
from accomplishing his ambitious goal, though he did succeed in
translating Aristotle's *Categories, On Interpretation, Prior
Analytics,* and Porphyry's *Isagoge*. Moreover, Boethius
had hoped to write two commentaries on many of Aristotle's works: an
introductory commentary for students of philosophy and an advanced
commentary for philosophers. But again, his early death prevented him
from producing second commentaries. Like other Neoplatonic
commentaries, Boethius' work draws heavily from Porphyry and
perpetuates the view of the categories which became the canonical
interpretation of Aristotle's text, i.e., that it is a work about
vocal signs that signify things (Boethius 1847, 160 a-b).




Due to the closure of the Academy in 529 and the dominance of the
Latin language in the West to the virtual exclusion of Greek, little
of the ancient commentary tradition exerted any influence on the Latin
Middle Ages. Thus, in spite of the many commentaries produced in the
ancient world, the main texts available to authors dealing with
categories after the sixth century were Boethius' translation of and
Commentary on Aristotle's *Categories*, the *Categoriae
decem* (a Themistian paraphrase of Aristotle's *Categories*
traditionally attributed to St. Augustine), and a composite
translation which included the lemmata of Boethius' Commentary and
some glosses. A few other works refer to categories, such as
Porphyry's *Isagoge*, translated and commented on twice by
Boethius, and Boethius' two Commentaries on *On Interpretation*
and his treatise *On the Trinity*. However, the
growing interest in logic that began in the ninth century and then was
revived in the eleventh century made Boethius' translation and
Commentary on the *Categories* the center of attention on this
topic.


From the sixth to the ninth century, most commentaries on the
Categories were written in Syriac. These include commentaries by Paul
the Persian (fl. 550), Sergius of Res'aina (d. 536), Aba
of Kashkar (fl. c. 600), Silvanus of Qardu (early seventh century),
Athanasius of Balad (d. 687), Jacob of Edessa (d. 708), George of the
Arabs (d. 724), Theodore bar Koni (late eighth century), David bar
Paul (fl. 785), Mose bar Kepha (d. 903), and by
Hunayn ibn Ishaq. The last Commentary, in turn, appears to be
the source for the Arabic tradition (see King 2011).




Beginning in the tenth century, Islamic philosophers
such as Alfarabi (ca. 870-950), Avicenna (980-1037), and
Averroes (ca. 1126-98), produced commentaries, but their impact
in the West was felt only after the period of translations from Arabic
into Latin which began in Spain around the middle of the twelfth
century. This process introduced many technical terms that came to
have considerable impact on philosophical and theological
discussions. Also worth mentioning are the *Liber sex
principiorum,* an anonymous work traditionally ascribed to Gilbert
of Poitiers (1085/90-1154) that sought to expand Aristotle's
brief comments on the last six categories, and Peter Abelard
(1079-1142), who discussed categories in his work (see Marenbon
1997).




Although commentaries on Aristotle's *Categories* written
before 1200 tend to be expository, still they raise important
philosophical questions, such as whether the categories *time*
and *place* are synonymous with *when* and
*where*, or whether *action* and *passion* are
reducible to *motion*. Even more important is the lively debate
between realists and nominalists concerning whether categories are
words, concepts, or things (for Abelard's influence, see Marenbon
1997, 108). The position they take on it determines the discipline in
which they think the categories are studied and affect the degree of
isomorphism they believe holds between language (words), thought
(concepts), and reality (things). If Aristotle's *Categories*
is a book about words, then categories are studied in grammar; if it
is about concepts, they are studied in logic; and if it is about
extra-mental things, they are studied in metaphysics.




By the early thirteenth century, an inclusive view, according to which
Aristotle's *Categories* is about words, concepts, and things,
became standard. This view, shared by almost everyone up to Ockham
(Pini, 2003, 11-18), had two important results. First, it lent
support to the belief that categories are legitimately studied in
three disciplines: grammar, logic, and metaphysics, but especially in
logic and metaphysics. Second, it suggested a certain isomorphism
between language (words), thought (concepts), and reality
(things). The second point was supported by at least two passages in
Aristotle's writings. In *On the Soul*, Aristotle claims that
"in the case of objects which involve no matter...
speculative knowledge and its object are identical" (430a
3-4). And in the text of *On Interpretation* cited
earlier (16a 4-8) a similar point is made. Taken together,
these texts suggest that in some ways language (words), thought
(concepts), and reality (things) are like each other in important
ways, a fact that explains their relations.


## 4. Thirteenth Century




At the beginning of the thirteenth-century, works of Aristotle and
his Islamic commentators previously unknown in the Latin West became
available. Among these were four works on logic-*Prior*
and *Posterior Analytics, Topics,* and *Sophistical
Refutations*-that became known as the new
logic (*logica nova*) (Zupko 2003, 45). Their study did not
displace the study of the older ones (the old logic, or *logica
vetus*), but rather helped to intensify and expand it, and resulted
in an increase in both the number and the complexity
of the commentaries written about *Categories*. In addition,
works on metaphysics and natural philosophy, such as Aristotle's
*Metaphysics* and *Physics*, as well as commentaries by
Islamic authors on them, circulated widely. These works introduced
a new context and terminology in the discussion of
categories.




For example, an important factor in the new discussions was the
notion of science articulated by Aristotle in *Posterior
Analytics.* Generally, it was thought that scientific knowledge
involves three things: a definition, a list of the properties in the
technical Aristotelian sense of features not contained in the
definition but consequent upon it, and a causal analysis. Faced with
this notion, scholastics explicitly asked whether categories are the
subject of scientific knowledge, and if so, whether the scientific
knowledge in question is what Aristotle regarded as a
knowledge of fact (*scientia quia*) or a knowledge of reasoned
fact *(scientia propter quid)*. Eventually they asked whether
categories could be defined and the kind of definition they could have;
whether they have properties and, if so, what
properties they have; and whether a causal analysis of them is possible
and in what such an analysis would consist. These questions led them to
question the discipline in which categories are studied-is it
grammar, logic, or metaphysics?-and often forced them to modify
their views of both science and the categories (Pini 2003,
189-90).




A second important factor, found in Islamic commentators, was the
introduction of a distinction between first and second intentions, and
the understanding that the first are studied in metaphysics and other
sciences that deal with the extra-mental world, whereas the second are
studied in logic (Pini 2003). There was
considerable disagreement as to what these
"intentions" are, but Aquinas conceived the first as
concepts about things in the world (e.g., "cat" is a
concept about cats) and the second as concepts about other concepts
(e.g., "species" is a concept about such other concepts as
cat and human). This new terminology led thirteenth century authors to
ask what the concepts of category and of particular categories (e.g.,
substance or quality) are (first or second
intentions?), and how the notions of first and second intentions ought
to be understood.




A third factor, the isomorphism between language, thought, and reality
inherited from ancient discussions of Aristotle's view, prompted
scholastic attempts to establish (some scholars use
'derive' or even 'deduce') the exact number of
categories. Most popular among these was the effort to tie the
categories to different kinds of predication, but there were authors
who explored other possibilities, such as derivations based on the
modes of being. Although there are early hints at an attempt based on
predication in Simplicius' *Commentary on Aristotle's
"Categories,"* it was not until the middle of the
thirteenth century that commentators typically raised a separate
question concerning the number of categories, an issue often referred
to as *sufficientia praedicamentorum*. Albertus Magnus
(ca. 1200-1280), Simon of Faversham (ca. 1260-1306), Peter
of Auvergne (d. 1304), Radulphus Brito (ca. 1270-1320), and
Henry of Ghent (ca. 1217-93), among others, attempted to
determine the number of categories. The most famous and influential of
the authors who engaged in this exercise was Thomas Aquinas, who
followed Albertus Magnus in trying to derive the categories from modes
of predication. Simon of Faversham and Radulphus Brito, though,
followed the tradition of deriving them from modes of being. Later
thinkers, such as John Duns Scotus, doubted the possibility of such a
demonstration, and William of Ockham and John Buridan
(ca. 1300-1361), among others, went even further, rejecting the
view that there are ten categories of reality, let alone the
possibility of demonstrating that there are ten categories.


### 4.1 Robert Kilwardby (b. 1215, d. 1279)




Robert is responsible for one of the first Latin commentaries on
Aristotle's Categories since Boethius' Commentary over six centuries
earlier, even though his conception of logic is highly influenced by
Boethius. He developed a doctrine of a twofold consideration of
categories: categories are considered in one way in logic and they are
considered in another way in metaphysics. This twofold consideration
becomes important for subsequent philosophers, such as Aquinas and
Scotus, who maintain that in logic, categories have one set of
properties, whereas in metaphysics, they have another set of
properties. 




Kilwardby is also responsible for propagating, if not developing, the
distinction between material and formal logic, where the former treats
of propositions and its parts (namely the categories), while the
latter treats the deductive structure of argumentation. (see Lewry,
1978, and Pini, 2002).


### 4.2 Albertus Magnus (b. 1200, d. 1280)




Although other commentaries on the categories were written shortly
after Kilwardby's Commentary (such as those written by Peter of Spain,
Roger Bacon, Nicholas of Paris, and Johannes Pagus), the most
important commentary was by Albertus Magnus. Albertus wrote
approximately seventy works, not counting his sermons and letters. A
large number of these were commentaries on the extant works of
Aristotle available to him at the time. Nine of these works are
devoted to logic, and of these, six are commentaries on Aristotle's
Organon. However, within these commentaries, there is strong
inclination towards a Neo-Platonic ontology which he barely
manages to keep apart from logic. 




An important element in Albert's Commentary is his derivation of the
ten categories, which was further developed and defended by his most
famous disciple, Thomas Aquinas. Albert takes the modi praedicandi as
his starting point in his division of the categories. The main
division is between per se predicaments and those not per se, i.e.,
between substance and accidents. The accidents are in turn divided
into absolute accidents and those with some sort of relation to
others. Absolute accidents are in turn divided on the basis of matter
(which gives rise to quantity) or form (which brings about
quality). Those accidents that have a relation to another are either
caused by the substance or by something extrinsic to the substance. As
to the accidents caused by the substance, they are either caused by
the form (which accounts for action), the matter (which accounts for
passion), or the entire composite (which accounts for relation). When
the relation is based on the parts to the whole, one has position. As
to the accidents caused by something extrinsic, if the cause is due to
proximity, there results the category of place. If the cause is due to
motion, the category of time results. Finally, the category of habit
results if the cause produces some addition to the substance. (For
more on Albert's derivation of the categories and how it influenced
Aquinas, see Bos 1998). 




Albert's Commentary is significant in that it is a close paraphrase of
the original Aristotelian text. (For its structure, see Ebbesen,
1981). Although there is no translation of it into English, there is a
new critical edition of it. 


### 4.3 Thomas Aquinas (b. 1224/6, d. 1274)




Unlike many of his contemporaries, Aquinas did not
compose a commentary on *Categories.* Nevertheless, there are
plenty of references to categories scattered throughout his writings.
Two texts are particularly important: one from his *Commentary on
Aristotle's "Metaphysics,"* the other from his
*Commentary on Aristotle's "Physics"*
(*Met*., V. lect. 9; nn. 889-91, *Phys*. III, lect.
5, nn. 310-20). These texts are important for understanding two
aspects of Aquinas' view, the derivation of the categories from
modes of predication and the isomorphism between language, thought, and
reality.




The derivation of the ten categories is most originally presented in
the *Commentary on the "Metaphysics."* Aquinas
begins by dividing being into three modes: outside the mind
(*extra* *animam*), in the mind (*in mente*), and
as divided into act and potency (*per potentiam et actum*).
Being, considered in the first way (which is the one pertinent to the
discussion here), is not divided as a genus (e.g., animal) is into
species (e.g., human) by means of differences (*differentiae,*
e.g., rational), because such differences need to be outside the
genus's essence (e.g., rationality is not included in animality),
and nothing lies outside being. Being, as found outside the mind, is
instead divided into categories *(praedicamenta)* on the basis
of how it is predicated *(modi praedicandi)*. Predication occurs
in three fundamental ways to indicate: (1) what a subject is (*id
quod est subiectum)*; (2) that something inheres in a
subject (*inest subiecto*); and (3) that something does not
inhere in the subject and is beyond it but nonetheless affects it
(*sumatur ab eo quod est extra subiectum*). These three modes of
predication are in turn divided and subdivided to account for the ten
categories.




In the first kind of predication, the predicate expresses what a
subject is. For example, in 'Socrates is a man,'
'man' indicates that Socrates *is* a man. Of course,
one can ask further what man is, and so on until one reaches the
highest term, which is substance. The same is true, *mutatis
mutandis*, of any other individual subject, for all subjects are in
the end some kind of primary substance, of which everything else is
predicated. This kind of predication accounts for the first and most
basic category, *substance* [*substantia*].




In the second kind of fundamental predication, the predicate
indicates inherence in a subject. According to Aquinas, this kind of
predication is initially divided into absolute (*per se et
absolute*) and relative (*in respectu ad aliud*). In
absolute predication the inherence comes from either the
subject's matter or form. When it comes from the matter, then the
predicate falls into the second category, *quantity*
[*quantitas*]. For example, in 'Socrates is five and a
half feet tall,' 'five and a half feet tall' is taken
from Socrates' matter. But when the inherence comes from the
form, the predicate falls into the third category, *quality*
[*qualitas*]. For example, in 'Socrates is
rational,' 'rational' is taken from the form of
Socrates, his humanity. If the predication is relative, however, then
the predicate falls into the fourth category, *relation* [*ad
aliud*]. For example, in 'Socrates is the father of
philosophy,' 'father' indicates the relation of
Socrates to philosophy.




In the third kind of fundamental predication, the predicate
indicates something that does not inhere in a subject and is beyond it,
although it affects it in some manner. This kind of predication
accounts for the remaining six categories. It is initially divided into
two sorts: those that are completely extrinsic to the subject
(*omnino extra subiectum*), and those that, while strictly
speaking are not in the subject, are nonetheless in some way in the
subject (*secundum aliquid sit in subiecto*).




The predications that are taken from something completely extrinsic
to the subject are divided into those that do not in any way measure
the subject and those that do. In the former, predicates indicate
something that affects the subject without measuring it. For example,
in 'Socrates is wearing clothes,' 'being
clothed' expresses that Socrates is affected but does not in any
way measure him. These predicates belong to the fifth category,
*habit* [*habitus*] (a habit is a garment used by the
religious). Predications that in some way indicate a measuring of a
subject are divided into those that measure time (e.g., in
'Socrates came yesterday,' 'yesterday' tells us
the pertinent time) and those that indicate place. In the first, the
predicates fall into the sixth category, *time*
[*quando*]*.* The second can in turn be divided into two
kinds: predications in which the predicate signifies the parts of a
subject in relation to one another and those that do not. For example,
in 'Socrates is sitting,' 'sitting' indicates
Socrates' position. Likewise, in the example, 'Socrates is
in the market place,' 'market place' identifies
Socrates' location. The first kind of predication accounts for
the seventh category, *position* [*situs*], and the
second for the eighth, *location* [*ubi*].




Predications indicating that something is not strictly speaking in
the subject but nonetheless in it in some way can be of two sorts. One
involves a cause of an action. For example, in 'Socrates is
teaching,' 'Socrates' refers to the cause of the
action of teaching, and therefore accounts for the ninth category,
*action* [*agere*]. The other involves being affected by
an action. For example, in 'Plato is being taught,'
'Plato' refers to the recipient of the action of teaching,
and therefore accounts for the tenth category, *passion*
[*pati*].




Fundamental to Aquinas' derivation of the categories is an isomorphism
between language and reality. Only because language parallels reality
in some way can Aquinas derive the ten categories of extra-mental
things from the ten different kinds of predication he accepts; we know
that there are ten different kinds of things based on the different
ways something is "said of" or "predicated of"
a subject. As John Wippel puts it, the "diverse modes of
predication correspond to and reflect diverse ways in which being
itself is realized, or what [Thomas] calls diverse modes of being
(*modi essendi*). Moreover, this diversity in the order of
predication follows from and depends upon diversity in the order of
being" (Wippel 1987, 17).




This isomorphism holds not only between language and reality, but
extends also to thought, which mediates between language and reality.
Again, as Wippel notes: "The mode or way in which words signify
does not immediately follow upon modes of being of such things, but
only as mediated by the way in which such things are understood"
(Wippel 1987, 17-18). Thus, one could say that things in the
world are isomorphic with concepts, and that concepts in turn are
isomorphic with words insofar as our use of language follows the way we
think and this in turn follows the way the world is.




For many medieval Aristotelians, the isomorphism between language,
thought, and reality does not apply only to the derivation of the ten
categories. A group of thirteenth-century thinkers commonly referred to
as the *modistae* go well beyond Aquinas in
this respect. Although there is little consensus on exactly who these
thinkers are, most accounts include Martin of Dacia (d. 1304), John of
Dacia (d. ca. 1280), Petrus Croccus (d. 1304), Michael of Marbais (fl.
ca. 1300), Radulphus Brito (ca. 1270-1320), and Thomas of Erfurt (fl.
ca. 1300). They are important in particular because of their views
concerning the strong isomorphism between language and reality. For
many of them this isomorphism is so profound that the boundaries
between grammar, logic, and metaphysics are either non-existent or
fuzzy. Thus, conclusions about the nature of things (reality) can be
derived from grammatical (language) or logical (thought)
considerations, just as Aquinas derives the ten ultimate
categories of reality from ten modes of predication. As Sten Ebbesen
describes it: "The basic idea of modism is this: each constituent
of reality (each *res*) has a number of ways or modes of being
(*modi essendi*) which determine the number of ways in which it
can be correctly conceptualized; the ways in which it can be
conceptualized (*modi intelligendi*) in turn determine in which
way it can be signified" (Ebbesen 1998, 274). Christian Kloesel
adds that by "discovering the logical structure and the causes of
language, a *modista* tried to explain the essential nature and
purpose of human speech and the ways in which words have meaning. [For
the *modistae* thought] that the structure of language mirrors
the structure of reality and the operations of the human mind"
(Kloesel 1981, 130).




Not every late medieval author held that one can
demonstrate the number of categories, or that there is an isomorphism
between language, thought, and reality. Some of them doubted
the possibility of proving that there are only ten
categories of reality, while some went so far as to reduce them to two
(Ockham) or three (Buridan).


## 5. Later Middle Ages




After Aquinas' death in 1274, the number of commentaries written on
Aristotle's *Categories* multiplied exponentially, of which, as
we said before, almost 200 are still extant, although virtually all
lack a critical edition and / or translation into English. That said,
the most prominent commentators include Giles of Rome, (b. ca. 1245,
d. 1316), Peter John Olivi (b. 1247, d. 1298), Dietrich of Freiberg
(b. ca. 1250, d. 1320), Walter Burley (b. ca. 1275, d. ca. 1345),
Antonius Andreae (b. ca.1280, d. 1320), Durand of St. Pourcain
(b. ca., 1275, d. 1334), Hervaeus Natalis (b. ca.1260, d. 1323), Peter
of Auvergne, John Buridan (b. 1295, d. 1358/61), Martin of Dacia
(d. 1304), Simon of Faversham (b. 1260, d. 1306), and Radulphus Brito
(b. 1270, d. 1320). 




Several points are worth noting about these commentaries: First,
Masters in the Arts faculty were formally forbidden from talking about
theological matters in their philosophical
commentaries. Notwithstanding this formal prohibition, the
commentaries on the categories were crucial for subsequent theological
discussions, and the thinnest of pretexts would sometimes occasion a
digression into theological territory. Perhaps the most important
topic was the definition of an accident and whether or not every
accident actually inhered in a substance or only had the potential so
to inhere in it. How one answered this question was extremely
significant in discussions of the Eucharist, in which the quantity of
the host, after consecration, no longer had a substance in which to
inhere. 




A second topic concerns the gradual shift away from exposition and
toward problem solving ('questions', as put by Andrews
2001). Even though the vast majority of these commentaries are not in
print and are difficult to obtain, the commentaries from the two most
influential authors in the later Middle Ages survive and are
available. John Duns Scotus' Commentary was written around 1295, and
William of Ockham's around 1319.


### 5.1 John Duns Scotus (b. ca. 1266, d. 1308)




According to Scotus, neither the logician nor the metaphysician is
capable of showing that there are ten categories. There are in fact ten
categories, but any attempt to prove that there are only ten is faulty.
In his *Questions on the "Metaphysics*," he puts it
thus: "The various ways for showing the sufficiency of the
categories [so far] all seem to err in two ways" (Scotus 1997, V,
q. 5-6, n. 73). The first error consists in the attempt to try to
prove that there are ten and only ten categories, for such a proof does
just the opposite. According to Scotus, purported demonstrations of ten
categories rely upon an initial division of predication into two basic
classes: predicates that indicate a "being in itself" and
predicates that indicate a "being not in itself." But this
implies that there are only two ultimate genera of being, not ten.
Indeed, if one were to accept that the modes of predication and the
modes of being correspond to each other, as those who try to derive the
number of categories from the modes of predication do, then one must
conclude that there are only two categories--substance and
accident, respectively--not ten. For the two most basic
kinds of predication are either "being in a subject" or
"not being in a subject."




The second error, Scotus argues, is begging the question. Any
attempt to demonstrate that there are only ten categories presupposes
the very thing to be demonstrated, namely, that there are ten and only
ten categories. "All these ways of dividing do not prove [the
proposal], for one would have to prove that what is divided is thus
divided, and precisely in this way, and this to the issue at hand,
namely, that the dividends constitute these most general
[categories]" (ibid., n. 75).




Even though Scotus does not believe that it can be demonstrated that
there are only ten categories, he accepts that there are in fact only
ten categories of being (Pini 2005). Clearly, for him, reality (the
actual number of categories) and what we know about them (what we can
demonstrate about them) do not correspond to each other. The
categories, as distinct kinds of things, are diverse from each other
and this diversity entails that there is nothing from which we can
establish their number. As Pini notes, "[e]ven when Scotus comes
to think that being is a univocal concept, he will always make clear
that there is no one real mode of being corresponding to that concept
from which the different categories can be derived. Metaphysically
speaking, there are ten irreducible essences, even though they can be
understood under a common concept" (Pini 2003, 13). Scotus'
view of categories reveals that he does not accept the isomorphism
between thought and reality common among medieval authors before him.
For him, however, the inability to deduce the number of categories is
only one of the ways in which signifying, understanding, and being are
not demonstrably isomorphic.




A second difference between the order of being (reality) and the
order of signifying (language) is revealed by the process known as
"contraction." In the conceptual order, a thing is
contracted from its genus to its species by a *differentia* that
distinguishes the species from other kinds within a genus. For example,
the genus "animal" is contracted to the species
"man" by the *differentia* "rational,"
thus setting human beings apart from other kinds of animals. In the
order of reality, however, being is not contracted to any of the ten
genera, because 'being' does not have the same meaning when
applied to every category. The ten highest genera have nothing in
common with each other other than the fact that they are called
'being' (Pini, 2005). However, insofar as the user of the
term is concerned, 'being' can be contracted to one of the
categories, for when one says 'being in itself,' one
intends to signify substance, even though in the order of reality no
such contraction occurs. This difference between reality and thought
lies at the heart of Scotus' doubt concerning the possibility of
deriving the number of categories.




Another example may help clarify the difference between the two
orders. Say that the word 'John' signifies at least two
persons: John Scotus and John Eriugena. This means that when one uses
the word 'John' to refer to these two persons, it is used
equivocally, for there is nothing common to both Scotus and Eriugena
that is signified by the term. Nevertheless, by adding a surname to
'John,' say 'Scotus,'
the name is contracted to 'John Scotus' as opposed to
'John Eriugena.' Now, when a nature (e.g., man) is
contracted in the extra-mental order to Scotus or Eriugena, the
nature, as it exists, is really contracted, but when 'John'
is contracted by the addition of 'Scotus,' the nature is
not contracted, only the utterance is. It is in this latter way, Scotus
argues, that the expressions 'being absolute' or
'being *per se*' contract 'being' to a
substance in the conceptual order, for this contraction is based on the
intent of the speaker, not on what is signified (i.e., not on the
extra-mental order).


### 5.2 William of Ockham (b. ca. 1285, d. 1347)




William of Ockham goes well beyond Scotus in his
rejection of any kind of isomorphism between words, concepts, and
things. Ockham is well known for what is usually called
"nominalism," that is, the view that universals or natures
do not have any ontological status outside the mind. Moreover, in
contrast to many fourteenth-century authors who posit ten categories,
Ockham argues that our experience leads us to posit only two
extra-mental categories: substance and quality.



> 
> 
> I claim that even though (I) the moderns hold that in every category
> there are many things ordered with respect to superiority and
> inferiority in such a way that, according to them, what is superior is
> predicated per se in the first mode and in the nominative case of each
> inferior ... and even though (ii), in order to have such
> predication, they fashion abstract names from adverbs ..., and
> even though (iii) they claim that there are ten primarily distinct
> "little things" that correspond in all cases to these
> abstract names, it nonetheless seems to me that the ancient
> philosophers did not posit such "little things," nor did
> they claim that it is always by this sort of predication that the
> categories are predicated of what is contained in them. (Ockham 1991,
> V. q. 22, 471-72)




The "little things" to which Ockham refers in this
passage are what Scotus calls "common natures," which
according to Scotus correspond to the different abstract predicates
found in each of the nine accidental categories. For Scotus, such terms
as 'squareness,' 'horseness,' and
'fatherhood' signify distinct and abstract existing
entities, a view Ockham rejects.




Following the standard medieval understanding of the opening lines of
Aristotle's *On Interpretation,* Ockham holds that written and
vocal words are conventional signs of mental concepts, which are in
turn natural signs of things. To a certain extent, he also admits that
written and vocal words correspond to mental concepts, so that, just
as there are ten kinds of predication, i.e., ten kinds of vocal
utterances (the ten categories), there are also ten kinds of concepts
corresponding to them (see Panaccio 1999, 55). However, Ockham argues
that our natural experience gives us no reason to think that the terms
we use for the categories signify ten extra-mental entities. Rather,
experience supports the view that only individual substances and the
accident of quality exist extramentally. Ockham uses many semantic
devices to make his point (ibid., 71). For example, whereas Scotus
might say that "Socrates is a father because of
fatherhood," Ockham would rather say that "Socrates is a
father because he has generated a son" (Ockham 1991, V. q. 22,
472; Klima 1999, 136). In this way, instead of positing an abstract
entity, viz., "fatherhood," to account for why Socrates is
a father, Ockham gives the activity of Socrates as an individual
substance as the reason why Socrates is a father. However, in other
contexts and for specifically theological reasons, particularly when
it comes to the cases of the Trinity, the Incarnation, and the
Eucharist, Ockham is willing to grant that relations are real. (see
Adams 1987, 267, and Spade 1999, 104)




Ockham is equally clear concerning the discipline that studies
categories. Like Buridan, among others, he held that they are studied
in grammar and logic, not in metaphysics. Aristotle's
*Categories* is concerned with words that
primarily signify things, and only indirectly with
things. As Ockham puts it in his early Commentary on Aristotle's
text:



> 
> 
> This is Boethius' intention, when he says: "He who deals
> with words that signify, also, in some fashion or other, will deal with
> things." For the thing and the signification of the thing are
> joined together. But this discussion which is about words is more
> primary, whereas that which is framed with respect to the notion of
> things, is secondary. That is, in the second place, he treats about
> those things for which [the words] stand. And ignorance of
> Aristotle's intention in this book leads many moderns astray,
> [the moderns] believing that he wants many utterances to be understood
> for things, which really are to be understood of words
> alone--and by way of analogy, for the intentions and
> concepts in the soul. (Ockham 1978, q. 1)




The ten categories, then, are studied both in grammar and logic,
albeit in different ways, but not in metaphysics. They are studied to
the extent that they signify things, but we must not suppose that
there is any one-to-one correspondence between words and concepts on
the one hand and things on the other. There is generally a one-to-one
correspondence between words and concepts, though even here this is
not always true. For example, in his *Summa logicae,* he
claims that participles and adjectives are distinct parts of speech
according to grammar, even though they are not distinct according to
logic (Ockham 1974, *SL* 3). Nevertheless, for Ockham, there
are ten categories of words and concepts, but the extra-mental things
that are signified by them are either individual substances or
individual qualities.




Ockham employs a number of distinctions in the exposition of his
account. One of these is particularly important for subsequent authors.
This is the distinction between "category" taken as one of
the ten highest genera (e.g., substance, quantity, quality, etc.) and
"category" taken as the set of coordinated
predicates contained in each of these genera. In the
former sense, the term 'category' refers to each of the ten
highest genera, whereas in the latter sense, the term refers to any set
of predicates ordered to one another. The most famous example of the
latter is Porphyry's tree, which starts out with
"substance" at the top and includes in descending order
such items as "corporeal," "living,"
"animal," and "man." In the *Summa
logicae,* Ockham presents the distinction as follows:



> 
> 
> '[C]ategory' has two senses. In one sense, it is used to
> signify the whole series of terms ordered according to greater and
> lesser generality. In the other sense, the word is used for the first
> and most general term in each such series. In the second sense of
> 'category,' every category is a simple term of first
> intention.... inasmuch as it signifies things which are not signs.
> (Ockham 1974, *SL* 40) 




Ockham's view does not go unchallenged.
Walter Burley (ca. 1275-1344/5), for example, develops his mature
doctrine of categories in opposition to Ockham in his *Commentary on
the Old Logic* (Conti 1990) and influences such later medieval
realists as Robert Arlyngton (fl. 1390), John Sharpe (1360-1415),
and John Wyclif (1324-1384).


## 6. Silver Age of Scholasticism




From about 1350 to about 1450, scholastic thought was in retreat. At
least two factors seem to have contributed to this
situation: first, the epidemic known as the Black Death decimated the
universities of medieval Europe, where scholastic thought had
flourished in the thirteenth century; second, the Italian Renaissance
began moving forward at high speed with its emphasis on the discovery
of the ancients and its rejection of "the age in the
middle." However, after the middle of the fifteenth century,
particularly following the integration of the Iberian peninsula at the
end of the century and the consolidation of the Spanish Empire, there
was a resurgence of scholasticism in the Iberian and Italian
peninsulas. The Counter Reformation, a movement within the Catholic
Church intended to meet the challenge of the Reformation, also
contributed substantially to the rebirth of scholastic thought. Among
the great leaders of this movement were the Italian Thomas de Vio, also
known as Cajetan (1468-1534), and the Spaniard Francis Suarez.
Both had enormous influence on all subsequent
scholastics and scholastically-inspired thought. Indeed,
Suarez's *Metaphysical Disputations* (1597) became
the standard textbook of metaphysics in Europe and
Latin America for one hundred and fifty years after its publication,
which means that what he has to say about categories is important for
understanding late scholastic category theory and the discussions of
the categories in Early Modern philosophy. Apart from questions of
originality, Suarez is historically important because he was a
bridge for metaphysical thought between the Middle Ages and the Modern
period.


### 6.1 Francis Suarez (b. 1548, d. 1617)




Suarez deals with categories in some detail in Disputation 39
of the *Metaphysical Disputations* (henceforth DM), although he
also makes pertinent comments about them elsewhere (for example, in DE
q. 75, a. 1, d. 47, s. 1, n. 4; 1861 vol. 21, p. 45a). In Metaphysical
Disputation 39, he is primarily concerned with the division of
accidents into nine highest genera, and the discussion of categories
is incidental and indirect, rather than deliberate and
explicit. Nonetheless, it is clear that Suarez is concerned
with the ontological status of categories in this text. Indeed, he
explicitly adopts a certain language in order to clarify and resolve
the issue.




Several aspects of Suarez's doctrine reveal his overall
position. Three of these are particularly enlightening: First, the
distinction between supreme genera and categories; second, the
respective disciplines where these are studied; and third, the kind of
distinction that obtains between categories themselves.




Medieval authors frequently use, interchangeably, the expressions
'supreme genus' [*generalissimum*] and
'category' (*praedicamentum*). The fact that these
terms are interchanged indicates that those who use
them regard them as equivalent at least in certain contexts.
Suarez is no exception; he often uses one term in place of the
other. But there is a difference, for Suarez is aware of the
difference in terminology and explicitly distinguishes between the two
expressions. In a revealing passage, he tells us that "a category
is nothing other than the *appropriate disposition* of genera
and species from a supreme genus to individuals" (DM 39, 1; 1861,
25:504b; our emphasis). This text makes clear that a category is not a
genus insofar as categories are *dispositions* of genera and
species. Genera are not dispositions, whereas categories are. This
means that, strictly speaking, categories cannot be supreme genera. In
another text Suarez is even more explicit:



> 
> 
> [A] category is nothing other than the *appropriate
> disposition* and *coordination* of essential predicates, of
> which those which are predicated essentially of the individual are
> placed above it, in a direct line, going up from the lower to the
> higher; and this line, just as it does not begin but with the lowest,
> that is the individual, does not end but in a highest genus ...
> ." (DM 39, 2, 30; 1861, 25:518; our emphasis)




Here, Suarez repeats that categories are dispositions, but he
adds another important term, 'coordination.' A category is
not properly speaking a genus, but rather the coordination or, we might
say, the arrangement of genera according to a pattern of essential
inclusion which goes from the lowest to the highest (see Ockham 1991,
V, q. 21, for a precedent to this language). We take it that
Suarez means to say that categories such as *quality* and
*quantity*, for example, are not themselves genera, but ways in
which genera are related. *Quality* tells us how *color*
is related to *red* and *blue* on the one hand (i.e.,
lower species), and to *texture* and *knowledge* (i.e.,
other genera) on the other. *Red* and *blue* are both
colors, but different from *rough* (a kind of texture) and
*knowledge of grammar* (a kind of knowledge). But all these are
qualities and different from *three-inches wide*, which is
instead a quantity. *Quality* and *quantity*, then, do
not function like genera, for a genus is signified by any predicate
that expresses what a subject is (e.g., in the sentence, 'Man is
an animal,' 'animal' is the genus of man), and
categories do not function in this way. Following Porphyry's
example, the highest or supreme (*generalissimum*) genus is
substance.




This brings us to the discipline under which categories are studied.
Suarez tells us that the division into nine highest
genera-he is speaking of accidental genera, although what he
says also applies *mutatis mutandis* to substance-is
proposed not only by metaphysicians, but also by logicians in treatises
on categories. Consequently, in one way it properly belongs to first
philosophy, that is, metaphysics, rather than logic. The reason is
that, whereas the metaphysician studies the ten supreme genera in order
to explain their natures and essences, the logician does not have this
aim in mind. Logic is directed toward the operations of the mind,
rather than toward natures and essences, and its purpose is to
establish rational ways of thinking. Logic deals with the concepts of
the mind insofar as these concepts can be arranged in accordance with
certain rules (DM 39, 1; 1861, 25:504b).




In another way, however, the categories are also studied in logic,
not in metaphysics, because they are mental concepts, and logic is
concerned with the proper analysis of concepts to determine their form
and with the proper arrangement of concepts to determine their
relations. But this is not the whole story, for Suarez also
speaks of the ten supreme genera, and the study of these belongs to
metaphysics. Moreover, there is also another important point, which is
made explicit in the following text:



> 
> 
> Because mental concepts are about real things, and are founded on
> real things, [the logician also] treats of real things, although not to
> explain their essences and natures, but only in order to coordinate the
> concepts in the mind; and in this sense he deals with the ten [supreme]
> genera in order to establish the ten categories. (DM 39, 1; 1861,
> 25:504b)




The logician treats of categories, which are ways in which concepts
are appropriately arranged in the mind. However, because these concepts
reflect the ways things are in reality, that is, the natures and
essences of things in the world, the logician also deals, albeit only
indirectly, with these natures and essences in order to be able to
introduce the proper order among them in the mind. The metaphysician,
on the other hand, deals directly with the ten supreme genera, not with
ways of arranging concepts in the mind, for the purpose of metaphysics
is to determine the essences of things.




Suarez makes an interesting aside in the discussion. He tells
us that some authors mistakenly consider categories to be names, and
only names. This mistake arises because they look at categories only
from the point of view of the logician, and the logician, qua logician,
is not concerned with an ordering on the basis of the essences of
things but on the basis of the essences of names (DM 39, 1; 1861,
25:505a).




The view that categories are concepts is supported further in his
discussion of the distinction among categories. Suarez, like the
other scholastics who precede him, holds that
categories are primarily diverse. This means that they share no common
property or genus. Naturally, the question as to the source and nature
of their diversity comes up, and Suarez discusses it in some
detail. For us, the important point is the nature of the distinction
among categories themselves. Suarez rejects two opinions with
respect to this issue. According to one, a real distinction between the
things contained under a genus is necessary (DM 39, 2, 19; 1861, 25:
515a). According to another opinion, the distinction between supreme
genera must be modal, actual, and *ex natura rei*, and must
precede in reality the operation of the mind (DM 39, 2, 20; 1861,
25:515b).




The view Suarez proposes holds that categories are
distinguished according to "our way of conceiving, founded in
reality. Some call this kind of distinction a distinction of reasoned
reason, whereas others call it formal distinction" (DM 39, 2, 22;
1861, 25:516b). The distinction of reasoned reason is, according to
Suarez, a conceptual distinction. Conceptual distinctions come
in two varieties: One is the distinction of reasoned reason and the
other the distinction of reasoning reason. The second has no basis in
reality but is purely a creation of the mind; it arises out of the
intellect's activity of comparing, which makes possible its
infinite multiplication (DM 39, 2, 23; 1861, 25:517a). An example is
the distinction between Peter and himself in order to say that he is
identical to himself. The first, however, the distinction of reasoned
reason, has a foundation in reality, even if the distinction itself is
merely conceptual. This is the kind of distinction that we make when we
think about God's attributes, for example. The foundation of this
distinction in the case of categories must be sufficient to allow
relations or modes of denomination of primary substance that are
irreducible to one generic concept (DM 39, 2, 23; 1861, 25:517a).




This is obviously not enough to clarify the issue. The question
remains: What is this foundation in reality which is the basis of the
denomination? It cannot be a category itself, for categories for
Suarez are concepts and the product of conception and
abstraction (DM 39, 2, 23; 1861, 25:517a). And it cannot be a reality
which is exactly represented by the distinction, for then the
distinction would be real rather than conceptual. So what is it?




The point to consider is that a distinction of reasoned reason has
some basis in reality, even though the distinction itself is a concept
in the mind, resulting from some comparison or of thinking about
something. Now we can go back to categories and apply what we have
learned about the distinction of reasoned reason to them. Categories
are ways in which humans conceive the world based on certain
comparisons that the mind carries out between other concepts, but these
other concepts have reference in the world. An example would help, but
the one of God and His properties, which Suarez gives, is of no
great use because of its uniqueness. Let us try to make up one that
perhaps Suarez would accept.




Consider the category *quality*. For Suarez,
*quality* is a concept which the mind develops based on the
mind's consideration of the relations between certain concepts,
such as *red*, *blue*, *grammatical*, and so on,
on the one hand, and certain other concepts on the other, such as
*three meters long*, *yesterday*, *woman*, and so
on. In other words, quality tells us something about the first set of
concepts and their relations to other concepts. But the concepts
between which relations are established have instances in reality,
outside the mind, though not *qua* concepts. *Red*, as
universal, is not to be found outside the mind. Nonetheless, there are
red things in the world and each of them is an individual instance of
the universal *red*. This means that *quality*, in spite
of being a concept based on the relation between concepts is
nonetheless related, via those concepts, to the world outside the mind.
And the same applies to the other concepts. So here we have the
foundation in reality of the category *quality*.


## 7. Concluding Remarks




Even the cursory discussion we have presented here should make a few
things clear about the development of category theory in the Middle
Ages. First, Aristotle's views had an extraordinary impact
throughout the period, for his *Categories* were ever-present in
medieval discussions of categories. Second, major changes occurred in
thinking about this topic depending on the availability of various
sources and the impact of different philosophical traditions. In the
early Middle Ages, Neoplatonic works such as the *Categoriae
decem* were very important, whereas later the influence of these
works faded and a more Aristotelian approach became dominant. Third, in
spite of Aristotle's influence, medieval authors charted new
courses, which often went contrary to Aristotle's explicit views;
we need only think of the number of categories, for example. They also
raised questions that were not explicitly posed by Aristotle, such as
the way that categories are established. Fourth, there was considerable
development in the way in which the general topic of categories was
discussed and the tools used to deal with it; late medieval logic
played an increasingly important role in discussions, the terminology
became more precise, the questions raised were made explicit, and the
controversies were increasingly pointed. Finally, the relevance of
categories for metaphysical issues became crucial, so that it was in
the context of metaphysical works, such as Aquinas'
*Commentary on Aristotle's "Metaphysics"* and
Suarez's *Metaphysical Disputations* that we find
some of the richest discussions.