## 1. The "most famous pair"




Some historians of medieval philosophy describe what they see as an
Augustinian "doctrinal complex" that emerged in the late twelfth and
early thirteenth centuries and that was the "common teaching" among
scholastics after the 
 1220s.[1]
 Weisheipl [1980], pp. 242-43, lists five ingredients of this
"Augustinian" 
 synthesis:[2]


1. voluntarism (an emphasis on the role of the will as distinct from
the intellect)
2. universal hylomorphism
3. plurality of forms
4. divine illumination, interpreted through the influence of
Avicenna
5. the real identity of the soul with its powers or faculties.




The second and third items on this list together make up what is
sometimes called the *"binarium famosissimum,"* the "most famous
pair."


### 1.1 Universal hylomorphism




Paul Woodruff has defined hylomorphism as "the doctrine, first
taught by Aristotle, that concrete substance consists of forms in
matter (*hyle*)" (Audi [1999], p. 408). One might therefore
expect *universal* hylomorphism to be the doctrine that
*all* substances consist of forms in matter. But in fact the
medieval theory of universal hylomorphism maintained something slightly
weaker than that; it held that all substances *except God* were
composed of matter and form, whereas God is entirely immaterial.




This view seems to be the result of two more basic theses:


* the explicit claim that only God is metaphysically simple in all
respects, so that all creatures are metaphysically composite;
* the view, not always explicitly spelled
out, that all composition is in some way a composition of matter and
form, an indeterminate factor and a determining element.




The reasoning behind the second thesis is murky. On the other hand,
it is easy to find medieval authors who argue in detail for the
first
 claim.[3]
 Still, it is surprisingly hard to find any medieval author who gives
a good *motivation* for it. That is, why should it be
*important* to maintain that God and only God is metaphysically
simple? What rests on the claim?




It it tempting, and plausible, to suppose that the implicit
reasoning goes something like this: "Composite" (*com* +
*positus* = "put together") things don't just *happen* to
be composite; something put them together. In short, composition
requires an efficient cause. It follows therefore that God, as first
cause, cannot be composite. Conversely, anything that is caused is in
some sense composite. Hence, since everything besides God is created
and therefore caused, everything other than God is composite. In short,
the unique simplicity of God is important to maintain because it is
required by the doctrine of creation. Nevertheless, while this line of
reasoning is plausible, it is not found clearly stated in any medieval
author I know
 of.[4]




The notion that all creatures are composites of matter and form
requires that something be said about what we might otherwise call
"immaterial" substances--angels, Aristotelian "separated
substances," the human soul after death. For universal hylomorphism,
such entities cannot be truly immaterial, and yet they are obviously
quite unlike familiar physical objects. As a result, universal
hylomorphists distinguished between "corporeal" matter, i.e., the
matter of physical, sensible objects, and another kind of matter
sometimes called
 "spiritual matter."[5]


### 1.2 Plurality of forms




The theory known as "plurality of forms" is not just the theory that
there are typically many forms in a material substance. That would
have been an innocuous claim; everyone agreed that material substances
routinely have many *accidental* forms. The theory of plurality
of forms is instead the theory that there is a plurality of
*substantial* forms in a given material substance. Details of
the theory varied widely from author to
 author.[6]
 There was some disagreement over how many substantial forms were
involved. Most people who held a version of this theory agreed that at
least a "form of corporeity" was required in all physical substances,
but they disagreed over how many additional substantial forms were
required for a given kind of body. Particular attention was given to
the case of the *human* body.




The arguments in support of this theory were quite diverse, and come
from a variety of directions. William of Ockham, for instance, held
that if the form of corporeity were not distinct from the intellective
soul and were not essentially present in the human being both during
his life and after the intellective soul departs at death, then once a
saint had died it would be false to say that the body that remains is
the body that saint ever had. Hence the cult of venerating the bodies
of the saints would make no sense. (*Quodlibet* II, q.
 11.[7])




Again, Thomas Aquinas, although he rejects plurality or forms,
nevertheless records several arguments given on its behalf. Among
 them[8]



> 
> 
> 
> Furthermore, before the coming of the rational soul the body in the
> womb of the mother has some form. Now when the rational soul comes, it
> cannot be said that this form disappears, because it does not lapse
> into nothingness, nor would it be possible to specify anything into
> which it might return. Therefore, some form exists in the matter
> previous to the rational soul ...
> 
> 
> 
> 
> Furthermore, in VII *Metaphysica* [11, 1036a 26] it is said
> that every definition has parts, and that the parts of a definition are
> forms. In anything that is defined, therefore, there must be several
> forms. Since, therefore, man is a kind of defined thing, it is
> necessary to posit in him several forms; and so some form exists before
> the rational soul.
> 
> 
> 


## 2. Proponents and opponents




The theories of universal hylomorphism and plurality of forms are
found together in many authors from the twelfth and thirteenth
century. They are both held, for instance, by the author known to the
scholastics as "Avicebron" (or Avicebrol, Avencebrol, etc.), who is to
be identified with the Spanish Jewish philosopher and poet Solomon Ibn
Gabirol (c. 1022-c. 1052/c. 1070), and whose *Mekor Hayyim*
(= *Fons vitae,* "Fountain of Life") was translated into Latin
in the late-twelfth
 century.[9]
 Indeed, medieval as well as modern scholars have sometimes looked to
Ibn Gabirol as the main source for the two doctrines in the thirteenth
 century.[10]
 Other authors who held both theories included the translator of the
*Fons vitae,* one Dominic Gundisalvi 
 (Gundissalinus)[11]
 as well as people as diverse as Thomas of 
 York,[12]
 St. 
 Bonaventure,[13]
 the anonymous thirteenth-century *Summa philosophiae* once
ascribed to Robert
 Grosseteste,[14]
 John Pecham, Richard of
 Mediavilla,[15]
 and many
 others.[16]




But other authors rejected these two views. The best known is no
doubt Thomas Aquinas. Aquinas held that the
uniqueness of God's absolute simplicity does *not* require positing a
kind of matter in all creatures. Rather all creatures, including
incorporeal substances such as angels or human souls, are composite
insofar as they have a composition of essence and *esse* ("to
be," the act of existing), whether or not they have an additional
composition or matter and
 form.[17]
 Again, he argues that if any substance has a plurality of forms, only
the *first* form that comes to it can be a substantial form;
all the others must be accidental
 forms.[18]
 Godfrey of Fontaines likewise rejected both theories. John Duns
Scotus accepted plurality of forms, but denied universal
 hylomorphism.[19]


## 3. The expression *"binarium famosissimum"*




The expression *"binarium famosissimum"* is not a medieval label
for this pairing of doctrines; its use in this sense appears to be
purely a twentieth-century development. Oddly enough, only *a single
occurrence* of the expression has been found in a medieval text,
the anonymous *Summa philosophiae* cited
 above.[20]
 But it clear that this author uses the expression to refer not to a
pair of doctrines, whether to universal hylomorphism and plurality of
forms or to any other pair, but to the division of substance into
corporeal and
 incorporeal[21]:



> 
>  Now the first contrariety in the categorial line of substance, from
> the nature of genus, partly by reason of the matter related to both
> sides [i.e., to corporeal and incorporeal], partly from the nature of
> the most common form tending to particularity by degrees according to
> the proportion of the matter's receptivity, contains the *binarium
> famosissimum,* that is, corporeal and incorporeal.
> 




On the other hand, as early as 1943 Daniel Callus writes of a
certain John Blund, an early-thirteenth century Englishman who rejected
both universal hylomorphism and plurality of forms. Callus says [1943], p. 252:



> 
>  More than Gundissalinus, we see delineated in Blund the great
> questions which in the second half of that century were to divide the
> different schools into two opposing armies, the outlining of the
> conflict between philosophers and theologians, Aristotelians and the
> so-called Augustinians. In Blund we meet with the earliest, clear, and
> unmistakable account of the *binarium famosissimum* of the
> Augustinians, Plurality of Forms and hylomorphic composition of
> spiritual substances, the angels and the human soul.
>  




Again, in a paper delivered in 1946, Callus [1955], p. 4, mentions
the "*binarium famosissimum,* the twofold pillar on which the
whole structure of the Augustinian school was supposed to stand."
Although he does not there say what this "twofold pillar" is, a few
pages later (p. 9) he cites "the *famosissimum binarium
Augustinianum,* namely, the hylomorphic composition of all created
beings, not only corporeal but also spiritual substances, the angels
and the human soul; and plurality of forms in one and the same
individual."




A few years later Etienne Gilson [1955], p. 377, in the
discussion of Thomas Aquinas in his monumental *History of Christian
Philosophy in the Middle Ages,* says:



> 
> 
>  The radical elimination of the *binarium famosissimum,* i.e.,
> hylomorphism and the plurality of forms, was not due to a more correct
> understanding of the metaphysics of Aristotle but to the introduction,
> by Thomas Aquinas, of a new metaphysical notion of being.
> 
> 
> 




Again, Weisheipl [1980], p. 250, writing about Albert the Great,
says (the emphasis is Weisheipl's):



> 
> Thus Albert is quick to point out that Avicebron in the *Fons
> vitae* is "the only [philosopher] who says that from one simple
> principle two [things] must immediately proceed in the order of
> nature, since the number 'two' follows upon unity." And
> Saint Thomas notes: "Some say that the soul and absolutely every
> substance besides God is composed of matter and form; indeed the
> *first author to hold this position is Avicebron,* the author
> of *Liber fons vitae*." This is the origin of the later
> *binarium famosissimum*: after One must come Two.
>  




In this passage, Weisheipl uses the phrase *"binarium
famosissimum"* in a sense perhaps loosely related to that used by
the author of the *Summa philosophiae.* But he also links it,
via the quotation from Aquinas, to the doctrine of universal
 hylomorphism.[22]




A few years later, Weisheipl ([1984], p. 451), speaking about Robert Grosseteste, remarks that he:



> 
> saw no problem whatever in accepting universal hylomorphism or a plurality of forms in a single material composite. Not only were these two tenets, known as the *binarium famosissimum,* common in the 1220s and 1230s, they were accepted as 'traditional' teaching by Franciscans at Oxford and Paris throughout the thirteenth century. John Peckham, Matthew of Aquasparta, Richard of Mediavilla, Roger Bacon, the pseudo-Grosseteste and even John Duns Scotus took the *binarium famosissimum* as orthodox Augustinian doctrine against the 'novelties' of Albert the Great and Thomas Aquinas.[23]
> 




Again, E. A. Synan [1993], p. 236, refers to Aquinas's denial that
there can be a plurality of substantial forms in any given substance,
and calls it a "rejection of one half of the *binarium
famosissimum.*"


## 4. Conceptual issues




Thus, although Gilson and some other twentieth-century scholars have
paired the theories of universal hylomorphism and plurality of forms
under the title *"binarium famosissimum,"* and although it is
certainly true that many medieval authors held both theories, there is
no evidence that in medieval times they were ever thought of as a
"pair" in this way.




Why then have some recent scholars linked the two theories so
closely? They certainly have done so. Weisheipl ([1980], p. 243), for
example, describes the plurality of forms as "simply a logical
consequence of" universal hylomorphism. And Zavalloni ([1951], p. 437,
n. 61) likewise claims that universal hylomorphism necessarily implies
plurality of forms, although he says the latter does not imply the
 former.[24]




What may be going on is this. The theory of universal hylomorphism
closely fits the view that the structure of what we truly say about
things mirrors the structure of the things themselves. Thus, if I truly
say 'The cat is black', then there is a cat that corresponds to the
subject term, and that cat is qualified by the quality blackness corresponding to the predicate term.
Without the blackness, the cat is to that extent indeterminate. It is
the addition of blackness that determines the cat to the particular
color it has. In general then, the relation of subject to predicate in
a true affirmative judgment is the relation of what is at least
relatively indeterminate to what at least partially determines it. Now
the relation of something indeterminate to what determines it is a
relation of "matter" to 
 "form."[25]
 Hence everything we can truly say about a subject reflects the fact
that the thing is composed of an indeterminate side and a determining
element--of matter and form. In short, hylomorphic composition
is involved in anything we can make true affirmations
about--thus, universal
 hylomorphism.[26]




Of course, we can truly say many things about a given subject. (E.g.,
'The cat is black', 'The cat is fat',
'The cat is asleep', etc.) The predicates of all these
true statements correspond to forms really inhering in the relatively
indeterminate subject. Hence we can speak of a "plurality of forms."
But the "plurality of forms," in the sense in which our authors speak
of it, refers to something more restricted, to the fact that we can
predicate predicates of a given subject *in a certain "nested"
order.* We can, for example, while taking about the very same cat,
say "This is a body" (i.e., it is corporeal), "This body is alive"
(i.e., it is an organism), "This organism is sensate" (i.e., it has
sensation, it is an animal), "This animal is a cat," "This cat is
black," etc. Each such predication attributes a form to the
underlying, "material," indeterminate subject, and each such subject
is in turn a composite of a form and a *deeper,* underlying
material subject. The picture we get then is the picture of some kind
of primordial *matter,* corresponding to the bare 'this'
of the first predication ("This is a body"), to which is added a
series of forms *one on top of the other* in a certain order,
each one limiting and narrowing down the preceding ones. The structure
that results is a kind of laminated structure, a metaphysical "onion"
with several layers. On this picture, of course, substantial and
accidental forms are both "layers of the onion" in exactly the same
sense. The distinction between essential and accidental features of a
thing would therefore have to be drawn in some other way.




If this reconstruction is more or less correct, then it is clear why
universal hylomorphism and plurality of forms can be viewed as
conceptually linked. Both fit nicely with the view that the structure
of reality is accurately mirrored in true predication. Ibn Gabirol,
who held both theories, seems to have been thinking along
approximately these lines. But some of the arguments cited above in
favor of plurality of forms show that at least that half of the "pair"
was sometimes held for entirely different reasons.




By contrast with the above reasoning, there is another view of
predication, an "Aristotelian" (and later, Thomistic) view that
rejects this picture. On this view, true predication in language is
not a reliable guide to the metaphysical structure of what makes it
true. One can truly *describe* a given subject in narrower and
narrower terms without there being any corresponding distinction of
real metaphysical components in what we are describing. We can, for
example, describe our cat as a body, as an organism, as an animal, and
as in particular a cat, all the while referring to *a single*
metaphysical configuration, a particular combination (in this case) of
matter and a feline form. Calling it a body, an organism, an animal,
before calling it a cat in no way reflects any sequence of
metaphysical distinctions in the entity itself. It is only when we
call it "black" that we introduce a new entity into the structure, an
*accident.* In short, on this alternative view, the structure
of reality is *not* accurately mirrored in true predication, at
least not in any straightforward way. This view is not committed to
any "plurality" of substantial forms, and is not committed to
universal hylomorphism
 either.[27]


## 5. Conclusion




The issues here are complex and the historical facts are not yet
well sorted out. But it appears that twentieth-century scholars who saw
a close conceptual link between universal hylomorphism and the
plurality of forms were perhaps thinking of the two theories as
motivated by a common commitment to the first theory of predication
described in SS 4 above. In some cases (for example the *Fons vitae*),
they probably were so motivated. Still, the fact that the two theories
are regarded as a "pair" is a recent phenomenon, not a medieval
one. It seems to have arisen first in the writings of Daniel Callus.[28]