## 1. Life and Works



The information on the life and works of William Penbygull (or
Penbegyll) is scanty. He was from Exeter diocese; he studied at
Oxford, where he was fellow of Exeter College in 1399, and rector in
1406-07. He was licensed to preach in the diocese of Bath and
Wells on 28 February 1410. He probably died at Oxford in 1420.
According to Emden 1957-59, he wrote the following treatises on
logic: *De universalibus* (*On Universals*), *Divisio
entis* (*The Division of Being*), and *Super Porphyrii
Isagogen* (*On Porphyry's Isagoge*). 


## 2. The Oxford Realists on Universals and Predication



The starting point of Penbygull's theories on universals and
predication are those worked out by Wyclif and one of his Oxford
followers of the generation leading up to Penbygull: Robert
Alyngton.



As is well known, Wyclif presents his opinion on universals as
intermediate between those of Thomas Aquinas and Giles of Rome, on the
one side, and Walter Burley, on the other (see the entry on 
 Wyclif). 
Like Giles Wyclif recognizes three main kinds of
universals: (1) ideal universals, which are the ideas in God and
archetypes of all that is; (2) formal universals, which are the common
natures shared by individual things; and (3) intentional universals,
which are the mental signs by which we refer to the formal universals,
or universals *in re*. On the other hand, like Burley, Wyclif
holds that formal universals exist outside our minds *in actu*
and not *in potentia*, even if, unlike Burley, he maintains
that they are really identical with their own individuals (*De enti
in communi*, ch. 5. p. 58). More precisely, universals and
individuals are really the same but formally distinct, since they
share the same empirical reality, which is that of individuals, but if
considered as universals and individuals, they have opposite
constituent principles: the generality or
natural-tendency-to-be-common for universals, and the thisness or
impossibility-of-being-common for individuals (see *Tractatus de
universalibus*, ch. 2, pp. 62-63, ch. 4, pp. 86-87; ch. 10, pp.
208-13).



This description of the logical relationship between universals and
individuals entailed the possibility of an indirect inherence of an
accidental form in a substantial universal and of a second intention
in any other. Therefore in the *Tractatus de universalibus*
Wyclif distinguished three main types of real predication in order to
guarantee such possibilities: formal predication (*praedicatio
formalis*), predication by essence (*praedicatio secundum
essentiam*), and habitudinal predication (*praedicatio secundum
habitudinem*). These three kinds of predication are described by
him as three non-mutually exclusive ways of predicating, each more
general than the preceding (*Tractatus de universalibus*, ch.
1, p. 35), but it is evident that habitudinal predication does not
require any kind of identity between the entities signified by the
subject and predicate terms in the same way as formal predication and
essential predication do. Formal predication is that in which the form
designated by the predicate-term is directly present in the entity
signified by the subject- term. Predication by essence (note that in
this expression the term 'essence' has Wyclif's technical
meaning of *real entity with a given nature*--see the entry on
 Wyclif) 
is that in which the same empirical reality is both
the real subject and predicate, even though the formal principle
connoted by the predicate-term differs from that connoted by the
subject-term. 'God is man' and 'The universal is
particular' are instances of this kind of predication. Finally,
habitudinal predication is that in which the form connoted by the
predicate-term does not inhere, directly or indirectly (namely, not by
itself but by means of something that is directly present in the thing
signified by the subject-term), in the essence designated by the
subject but simply implies a relation to it, so that the same
predicate may be at different times said truly or falsely of its
subject without any change in the subject itself (*Tractatus de
universalibus*, ch. 1, p. 34). According to Wyclif, we use such
predication mainly to express theological truths, such as God is known
and loved by many creatures or brings about, as efficient, exemplar,
and final cause many good effects.



As we have seen, the ontological presuppositions of the most general
type of predication differ completely from those of the other two
types by which it is implied. The final result of Wyclif's
choices was therefore an incompletely developed system of intensional
logic that he superimposed on the traditional system. Because the
ontological basis of the most general type of predication, namely
habitudinal predication, is completely different from those of the
other two types of predication that should imply it, Alyngton and
other Oxford authors of the subsequent generation tried to improve
Wyclif's theory by excluding habitudinal predication and
redefining the other two kinds in a slightly different way.



According to Alyngton, who depends on Avicenna and Wyclif on this
topic, the formal universals are common natures in virtue of which the
individuals that share them are exactly what they are, just as
humanity is the form by which every man formally is a man. Unlike
Wyclif, however, he does not think that universals exist *in
actu* in the external world (see Alyngton, *Litteralis
sententia super Praedicamenta Aristotelis*., ch. *de
substantia*, in A.D. Conti, "Linguaggio e realta nel
commento alle *Categorie* di Robert Alyngton," Appendix
(provisional edition of part of Alyngton's commentary on the
*Categories*), *Documenti e studi sulla tradizione
filosofica medievale*, 4 (1993): 179-306, at p. 279). As natures,
they are prior and indifferent to any division into universals and
individuals. Although universality is not a constitutive mark of the
nature itself, it is its unique, inseparable property. Also for
Alyngton, universals are really identical-to and formally
distinct-from their individuals. In fact, universals are formal causes
in relation to their own individuals, while individuals are material
causes in relation to their universals (see *Litteralis sententia
super Praedicamenta Aristotelis*., ch. *de substantia*, pp.
275-76). On this basis, Alyngton stated that (1) a universal in the
category of substance can directly receive only the predications of
substantial forms more common than it. So, for instance, only
*corporeity* and *animality* can be directly predicated
of *humanity*. And (2) the accidental forms inhering in
individual substances can be predicated of the universal substantial
form that those individuals instantiate only indirectly (or
*essentialiter* according to his terminology) through and in
virtue of the individuals themselves of that substantial form (see
*Litteralis sententia super Praedicamenta Aristotelis*., ch.
*de substantia*, pp. 288-89). For instance, the general form of
*whiteness* can be indirectly predicated of the general form of
*humanity* in virtue of the individual forms of
*whiteness* which inhere in individual men.



For this reason, Alyngton's description of the logical structure
of the relationship between universals and individuals demanded a
redefinition of predication. Indeed, he was the first one to
ameliorate Wyclif 's theory by dividing predication into
(1)formal predication (*praedicatio formalis*) and (2) remote
inherence (*inhaerentia remota*)--or, in other words,
predication by essence (*praedicatio secundum essentiam*).
Remote inherence is grounded on a partial identity between subject and
predicate, which share some, but not all, metaphysical constituents,
and does not demand that the form signified by the predicate-term be
directly present in the entity signified by the subject-term. On the
contrary, such a direct presence is required by formal predication.
'Man is an animal' and 'Socrates is white' are
instances of formal predication; '(What is) singular is (what
is) common' ('*singulare est commune*') and
'Humanity is (something) running' ('*humanitas
est currens*') are instances of remote inherence, since,
according to Alyngton, the property of running is imputable to the
form of humanity, if at least one man is running. He is careful,
however, to use a substantival adjective in its neuter form as a
predicate-term, because only in this way can it appear that the form
signified by the predicate-term is not directly present in the
subject, but is indirectly attributed to it through its individuals
(see *Litteralis sententia super Praedicamenta Aristotelis*.,
ch. *de substantia*, p. 289--see the entry on 
 Alyngton).


## 3. Penbygull on Universals and Predication



Like many other Oxford Realists, Penbygull lists three main kinds of
universals: (i) the metaphysical causes of everything, like God and
the angelic intelligences; (ii) the general concepts abstracted by our
mind, or mental universals; and (iii) the common natures existing in
the singulars, or real universals (*De universalibus*, p. 178).
Such common natures are type-forms naturally apt to be present-in and
predicated-of a set of individuals, which therefore instantiate them.
Real universals are the main metaphysical components of the
individuals, but they have no being outside the being of their
individuals, as universals and their individuals are really
(*realiter*) the same and only formally (*formaliter*)
distinct (*De universalibus*, p. 189). In fact, real universals
are identical with their own individuals when considered as natures of
a certain kind (for instance, man is the same thing as Socrates), but
different from them when considered *qua* universals and
*qua* individuals respectively, because of the opposite
constitutive principles: generality for universals and thisness for
individuals (*De universalibus*, p. 181). 



Like Walter Burley and Wyclif, Penbygull holds that such formal
universals exist in act (*in actu*) outside our minds, and not
in potency (*in potentia*) only, as moderate realists (like St.
Thomas Aquinas) thought, since for Penbygull the necessary and
sufficient condition that a thing must meet for being a universal is
the existence of at least one individual in which it is present
(*De universalibus*, p. 178). So the actual existence of
universals depends entirely on that of their individuals; without
them, common natures could not be really universals.



On the logical side, this description of the relationship between
universals and individuals in terms of real identity and formal
distinction, entails that not all that is predicated of individuals
can be *directly* (*formaliter*) attributed to their
universals and *vice versa*. In particular, the accidental
forms inhering in substantial individuals (for instance, the whiteness
inhering in Socrates) can be predicated of the universal forms proper
to these individuals (for instance, the form of humanity or that of
animality) only *indirectly* (*essentialiter*), through
and in virtue of the individuals themselves. As a consequence, a
redefinition of the standard kinds predication and the introduction of
a new type, unknown to Aristotle, was required, in order to cover the
cases of indirect inherence of an accidental form in a substantial
universal, admitted by this theory.



Penbygull, like other Oxford logicians of his generation, tried to
improve Wyclif's theory by excluding habitudinal predication and
redefining the other two kinds in a slightly different way. Penbygull
therefore divides predication (which he conceives as a real relation
which holds between metaphysical objects [*De universalibus*,
p. 188]) into formal predication (*praedicatio formalis*),
predication by essence (*secundum essentiam*), and causal
predication. Predication by essence shows a partial identity between
subject and predicate, which share some, but not all, metaphysical
component parts, and does not require that the form connotated by the
predicate-term be directly present in the essence denotated by the
subject-term. Formal predication, on the contrary, requires such a
direct presence. If the form connotated by the predicate-term is
intrinsic to the nature of the subject, then the predication is a case
of formal essential predication, while if it is extrinsic, the
predication is a case of formal accidental predication. "Man is
an animal" is an instance of formal essential predication;
"Socrates is white" is an instance of formal accidental
predication. Unlike Wyclif, who applied predication by essence to
second intentions only--since he admitted sentences like
"(What is) universal is (what is) singular" (that is,
*universale est singulare*) as well-formed and
true--Penbygull thinks that it holds also when applied to first
intentions. So he claims that it is possible to predicate of the
universal-man (*homo in communi*) the property of being white,
if at least one of its individuals is white. However he makes sure to
use as a predicate-term a substantival adjective in its neuter form,
because only in this way can it appear that the form connoted by the
predicate-term is not directly present in the subject, but is
indirectly attributed to it, through its individuals. Therefore he
acknowledges the proposition "The universal-man is (something)
white" (*homo in communi est album*) as a true one, if at
least one of the existing men is white (*De universalibus*, pp.
186-87). Finally, there is causal predication when the item
signified by the predicate-term is not present in any way in the item
signified by the subject-term, but the real subject has been caused by
the real predicate (*De universalibus*, p. 188).



According to him formal essential predication and formal accidental
predication would correspond to Aristotle's essential and accidental
predication. But, as a matter of fact, he agrees with Wyclif in
regarding predication by essence as more general than formal
predication. As a consequence, in his theory formal predication is a
particular type of predication by essence. This means that he
implicitly recognizes a single ontological pattern, founded on a sort
of partial identity, as the basis of every kind of standard
philosophical statement (subject, copula, predicate). But in this way,
formal essential predication and formal accidental predication are
very different from their Aristotelian models, as they express degrees
of identity as well as predication by essence.



Formal accidental predication is then further divided into
*secundum motum* and *secundum habitudinem* (*De
universalibus*, pp. 187-88). The basic idea of this last
division seems to be that modes of being and natures of the accidental
forms determine the set of substantial items which can play the role
of their substrate. Penbygull distinguishes between those accidental
forms that require a substance capable of undergoing change (*per
se mobile*) as their own direct substrate of inherence, and those
which do not need a substrate with such a characteristic. Forms like
quantity, whiteness, alteration, diminution and so on belong to the
first group, while relations of reason and *respectus*, like
causation, difference, and so on, fall under the second one. The forms
of the first group bring about formal accidental predication
*secundum motum*, and the forms of the second group formal
accidental predication *secundum habitudinem*. The former
necessarily entail singular substances as their substrates, since
individuals alone can undergo change, while the latter can directly
inhere in both individual and universal substances (*insunt
denominative tam communibus quam singularibus*--*De
universalibus*, p. 188).


## 4. Penbygull's Theory of Identity



This interpretative scheme of the nature and kinds of predication is
ultimately grounded on a notion of identity, necessarily different
from the standard one. According to the most common opinion the
logical criteria for identity and (real) distinction were the
following: 



> 
> *a* is identical with *b* if and only if for all
> *x*, *x* is predicated of *a* iff it is
> predicated of *b*;
> 
> 
> *a* differs from (is [really] distinct from) *b* iff
> there is at least one *z* such that *a* is predicated of
> *z* and *b* is not, or *vice versa*, or there is
> at least one *w* such that *w* is predicated of
> *a* and not of *b*, or *vice versa*.
> 
> 
> 



On this basis one can easily conclude that universals and individuals
can never be the same, at least because of the forms of generality
(which cannot be predicated of individuals) and of thisness (which
cannot be predicated of universals). So Penbygull had to put forward
new criteria for identity and distinction. First of all, he
distinguishes between the notion of non-identity and that of
difference (or distinction) and denies that the notion of difference
implies that of non-identity (*De universalibus*, p. 190); then
he affirms that the two notions of difference and (real) identity are
logically compatible (*ibid.*); finally he suggests the
following definitions for these three notions non-identity, difference
or distinction, and (absolute) identity (*De universalibus*,
pp. 190-91):



> 
> *a* is non-identical with *b* iff there is no form
> *F* such that *F* is present in the same way in
> *a* and *b*;
> 
> 
> *a* differs from *b* iff there is at least one form
> *F* such that *F* is *directly* present in
> *a* but not in *b* or vice versa;
> 
> 
> 
> *a* is (absolutely) identical with *b* if and only if
> for any form *F*, *F* is present in *a* iff it is
> present *in the same way* in *b*.
> 
> 
> 



The criterion for non-identity is stronger than the common one for
real distinction: two things can be qualified as non-identical iff
they belong to distinct categories. On the other side, the definition
of difference does not exclude the possibility that two things which
differ from each other share one or more properties (or forms). Thus,
there are degrees of distinction, and what is more, the degree of
distinction between two things can be read as the inverse measure of
their (partial) identity. For instance, if we compare the list of the
forms (both substantial and accidental) which constitute Socrates and
those which make up the universal-man, it is evident that Socrates and
the universal-man differ from each other, since there are forms which
directly inhere in Socrates and not in the universal-man and *vice
versa*; but it is also evident that the two lists are identical
for a long section, that is, that Socrates and the universal-man,
considered from the point of view of their metaphysical composition,
are partially the same. As a result, the copula of the propositions
which Penbygull deals with cannot be extensionally interpreted, as it
does not mean that a given object is a member of a certain set, nor
that a given set is included in another, but it always means degrees
in identity between two compound entities.