## 1. Life and works



William of Sherwood was born between 1200 and 1205, probably in
Nottinghamshire, and died between 1266 and 1272. His school career is
uncertain, but given references to his works and his influence on
people such as Peter of Spain, Lambert of Auxerre, Albert the Great,
and Thomas Aquinas, it is likely that he was teaching logic at the
University of Paris between 1235 and 1250. After that period, he seems
to have left logic. He was a master at Oxford in 1252 and treasurer of
the cathedral of Lincoln about two years later; still later, he was
rector at Aylesbury, in Buckinghamshire, and Attleborough, in Norfolk.
He was still alive in 1266 but dead by 1272 (Kretzmann 1968, p.
3).



Part of the difficulty with establishing his biography is that he has
previously been conflated with various other 13th-century Englishmen
named William, such as William of Leicester (d. 1213) and William of
Durham (d. 1249) (cf. Grabmann 1937, pp. 11-13; Kretzmann 1966, p. 3;
Mullinger 1873, p. 177). He has also sometimes been identified with
others bearing the same surname, such as the author of commentary, now
lost, on the *Sentences* of Peter Lombard with the title
*Shirovodus super sententias*, a work that was known to John
Leland in the 16th century (Kretzmann 1966, p. 12), or Ricardus de
Schirewode, who wrote a treatise on insolubles surviving in Cambridge,
St John's MS 100. This confusion, along with the usual problems
presented by anonymous material, makes it difficult to identify
William's works with certainty.



Two works can be confidently ascribed to Sherwood, an *Introduction
to Logic* and a treatise on syncategorematic terms, the
*Syncategoremata*. The *Introduction* survives in complete
form in only one manuscript, Bibliotheque Nationale MS. Lat.
16,617, from the late 13th or 14th century, which begins with the
heading *Introductiones Magistri Guilli. de Shyreswode in
logicam*, "Introduction to Logic of Master William of
Sherwood". The *Syncategoremata* immediately follows, and
is likewise explicitly attributed to Sherwood. The
*Syncategoremata* also survives in a second manuscript, Bodleian
MS Digby 55, where it is again explicitly labeled, *Sincategoreumata
Magistri Willielmi de Sirewode* "[Treatise on]
Syncategorematics of Master William of Sherwood", and Chapter
Five of the *Introduction* survives in a second manuscript, MS
Worcester Cath. Q. 13, written around 1293/94, and edited by Pinborg
& Ebbesen (1984).



The *Introduction* was almost certainly written while William was
lecturing on logic at the University of Paris. It was first edited by
Grabmann (1937) and translated into English by Kretzmann (1966). A new
critical edition was produced by Brands and Kann (1995), accompanied
by a translation into German. It has been argued (Mullinger 1873, p.
177) that this book was heavily influenced by a *Synopsis*
treatise written by the 11th-century Byzantine logician Michael
Constantine Psellus. The *Introduction* contains the first
appearance of the syllogistic mnemonic verse 'Barbara,
Celarent...', which Augustus de Morgan described as "magic
words ... more full of meaning than any that ever were made", and
Sherwood may even have been the inventor of the verse, though
references to individual names appear earlier (Kretzmann 1966, pp.
66-67).



Sherwood's treatise on syncategorematic terms has long been held to be
if not the earliest such treatise, then the earliest still accessible
(Boehner 1952, p. 7). The text was first edited by O'Donnell (1941),
and this edition along with the Paris MS was the basis of Kretzmann's
1968 translation into English. O'Donnell's edition has since been
superseded by the critical edition of Kann and Kirchhoff (2012), which
also includes a translation into German. Kirchhoff (2008) is an extensive discussion and commentary on the *Syncategormeta*.



Three other logical treatises follow the *Introductiones* and the
*Syncategoremata* in the Paris manuscript, which have as a result
been tentatively attributed to Sherwood. The first is a treatise on
insolubles, ff. 46-54, edited by Roure (1970), and the second a
treatise on *obligationes* found in Paris, Bibl. Nat. 16617. This
text was edited by Green (1963), who tentatively attributed it to
Sherwood. The third is the text *Petitiones Contrariorum*, edited
by de Rijk (1976), covering puzzles arising from hidden contradictions
in sets of premises. Sherwood may also be the author of the
*Fallaciae magistri Willelmi* "Fallacies, of Master
William" preserved in British Museum, King's Library MS 9 E XII,
as well as the treatise ascribed to Richard of Sherwood noted
above.



Three further treatises have previously also been attributed to
Sherwood, but the evidence for their attribution is less clear: the
commentary on the *Sentences* of Peter Lombard noted above, a
*Distictiones theologicae*, and a *Concionces*, or
collection of sermons (Kretzmann 1968, p. 4).


## 2. Important doctrines



Along with Peter of Spain, Lambert of Auxerre, and Roger Bacon,
William of Sherwood was one of the first terminist logicians, working
in a context where the newly discovered and translated Aristotelian
material of the 12th century had become fully integrated into the
logical and philosophical curricula through the works of people such
as John le Page (Uckelman & Lagerlund, 2016). The terminist period
of logic was marked by the development of logical genres and
techniques that go beyond Aristotle and mere commentaries on his
works. The two primary branches of terminist logic are the study of
the properties of terms and the study of the meaning and function of
syncategorematic words. Sherwood's *Introduction* picks up the
first of these two branches in its fifth chapter, and his
*Syncategoremata* deals with the second. The remainder of the
*Introductiones* is devoted to the standard Aristotelian
material: Chapter One on statements corresponds to *On
Interpretation*; Chapter Two on predicables to the
*Categories*; Chapter Three on syllogisms to the *Prior
Analytics*; Chapter Four on dialectical reasoning to the
*Topics*; and Chapter Six on sophistical reasoning to the
*Sophistical Refutations*. We will focus our attention in this
article on the unusual or distinctive aspects of his logical and
semantic theory, as found in Chapter Five of the *Introduction* and in the *Syncategoremata*.


### 2.1. Modality



In his *Introduction*, Sherwood gives two definitions for
'mode', depending on whether the term is being used
broadly or strictly: "Broadly speaking, a mode is the
determination of an act, and in this respect it goes together with
every adverb", while strictly speaking we count not all adverbs
as modes but only those which determine the inherence of the predicate
in the subject (Kretzmann 1966, p. 40). Thus, on the broad conception
of 'mode', both "Socrates is necessarily
running" and "Socrates is swiftly running" count as
modal statements, but on the narrow conception, only the former
does. The six modes are 'true', 'false',
'possible', 'contingent',
'impossible', and 'necessary', though
"the first two do not distinguish a modal proposition from an
assertoric statement" (Kretzmann 1966, pp. 40-41). The
other four modes give rise to properly modal propositions, and in
statements expressing these propositions, the associated modal adverbs
are 'possibly', 'contingently',
'impossibly', and 'necessarily'. Each of
these modal adverbs is a syncategorematic term; and in
the *Syncategoremata*, Sherwood devotes an entire chapter
to *necessario* ('necessarily')
and *contingenter* ('contingently').



Here it must be noted that Sherwood's views of modality differ
significantly from modern views. Modern modal logic interprets modes
in a nominal way, e.g., 'necessary:',
'impossible:', etc. But Sherwood is reluctant to admit a
statement such as "That Socrates is running is necessary"
as genuinely modal (Kretzmann 1966, p. 43), instead viewing this as an
assertoric categorical statement predicating 'necessary'
of "that Socrates is running". Similarly, "Socrates
is running necessarily" does not count as a modal statement,
because here 'necessarily' modifies 'running',
not "the inherence of the predicate in the subject". The
only genuinely modal construction is that exhibited by "Socrates
is necessarily running" (Kretzmann 1966, p. 42). The importance
of the adverbial construction, where the modal adverb modifies the
inherence of the predicate with the subject, is emphasized in the
discussions of modal adverbs in *Syncategoremata*, which include
not only the chapter mentioned above but also analyses of how modal
adverbs interact with other syncategorematic terms such as
"only", "unless", and "if"
(Uckelman 2020, SS5).



Since Aristotle it was standard practice to note that
'possible' can be used in two ways. In the first
'possible' is compatible with 'necessary', but
in the second, that which is necessary is not (merely) possible. This
second way is usually called 'contingent'. Sherwood
mentions this distinction, but goes on to say that he will be using it
in a broader sense, in which possibility is compatible with necessity
(Kretzmann 1966, p. 41). However, he makes a further distinction,
which he does maintain, between the two ways that
'impossible' and 'necessary' can be used.
These different ways are expressed in temporal notions:



> 
> 
> [impossible] is used in one way of whatever cannot be true now or in
> the future or in the past; and this is 'impossible *per
> se*' ... It is used in the other way of whatever cannot be
> true now or in the future although it could have been true in the
> past ... and this is 'impossible *per accidens*'.
> Similarly, in case something cannot be false now or in the future or
> in the past it is said to be 'necessary *per se*' ... But it
> is 'necessary *per accidens*' in case something cannot be
> false now or in the future although it could have been [false] in the
> past (Kretzmann 1966, p. 41).
> 
> 
> 



Sherwood says that the reason it is important to separate modal
propositions from assertoric ones is that



> 
> 
> [s]ince our treatment is oriented toward syllogism, we have to
> consider them under those differences that make a difference in
> syllogism. These are such differences as ... modal, assertoric; and
> others of that sort. For one syllogism differs from another as a
> result of those differences (Kretzmann 1966, p. 39).
> 
> 
> 



Despite this, there is "no treatment of modal syllogisms in any
of the works that have been ascribed to Sherwood" (Kretzmann
1966, p. 39, fn. 58). For more on Sherwood's account of modality, see
(Uckelman 2008).


### 2.2. Properties of terms



The theory of the "properties of terms" forms the basis of
medieval semantic theory and provides an account of how terms function
within the broader context of sentences, as well as how these
different functions can account for the different rules governing
inference. Sherwood identifies the four main properties of terms as
(1) signification; (2) supposition; (3) copulation; and (4)
appellation (Kretzmann 1966, p. 105). In this classification he
differs from other accounts which mention (1) signification; (2)
supposition and copulation; (3) ampliation and restriction; (4)
appellation; and (5) relation.



Sherwood defines 'signification' as "a presentation
of the form of something to the understanding", a definition
harking back to 12th-century semantic theory (Kretzmann 1966, p. 105,
fn. 2). Supposition and copulation are symmetrically related to each
other; 'supposition' is "an ordering of the
understanding of something under something else" while
'copulation' is "an ordering of the understanding of
something over something else" (Kretzmann 1966, p. 105). Only
substantive nouns, pronouns, and definite descriptions can have
supposition, while only adjectives, participles, and verbs can have
copulation (Kretzmann 1966, p. 106).



Finally, 'appellation' is "the present correct
application of a term -- i.e., the property with respect to which what
the term signifies can be said of something through the use of the
verb 'is'" (Kretzmann 1966, p. 106). That is, the
*appellata* of a term are the presently existing things of which
the term can currently be truly predicated. Appellation is between
supposition and copulation: Substantive nouns, adjectives, and
participles can have appellation, but pronouns and verbs cannot
(Kretzmann 1966, p. 106).



The central notion of these three is supposition, and the majority of
the chapter is devoted to the division of supposition into its various
kinds:



![Tree diagram: At the top is Supposition with 2 branches: Material and Formal; Formal has 2 branches: Simple and Personal; Simple has 3 leaves: Manerial, Reduplicative, and Unfixed; Personal has 2 branches: Determinate and Confused; Confused has 2 branches: Merely confused and Distributive confused; Distributive confused has 2 leaves: Mobile and Immobile.](sherwood-supposition.jpg)


For a discussion of most of the notions in this division as well as a
comparison of Sherwood's views to those of his 13th-century
contemporaries and his 14th-century posterity, see the article
 Medieval Theories: Properties of Terms.
 We briefly comment on 'manerial' supposition, a type
which does not appear outside of Sherwood. Some have considered
*manerialis* an error for *materialis*, and considered
Sherwood to have been talking here about material supposition
(Grabmann 1937). However, the manuscript shows *n* rather than
*t*, and the type of supposition is not the same as the material
supposition, which is distinguished from formal supposition, but is
itself a type of formal supposition. Sherwood says that manerial
supposition is a type of simple supposition in which "a word can
be posited for its *significatum* without any connection with
things", and he gives as an example "Man is a
species". The explanation is that this is manerial supposition
because 'man' "supposits for the specific character
in itself" (Kretzmann 1966, p. 111). The notion of
*maneries* meaning 'character, way, mode, manner' can
be found in 12th-century discussions of universals; for example, John
of Salisbury notes that Joscelin, Bishop of Soissons, says that
sometimes the words *genus* and *species* "are to be
understood as things of a universal kind" and sometimes he
"interprets them as modes (*maneries*) of things"
(Hall, Book II, ch. 17, p. 84). John says he does not know where
Joscelin got such a distinction, but it occurs in Abelard and in the
12th-century *Fallacie Parvipontane* (Hall, Book II, ch. 17, p.
84, fnn. a, b; de Rijk 1962, pp. 139, 562).


### 2.3. Semantics of universal affirmatives



Statements are composed of two types of parts: principal and
secondary. The principal parts of a statement are the nouns and verbs,
that is, the subjects and predicates whose properties are the focus of
the first branch of terminist logic. The secondary parts are those
that remain: "the adjectival name, the adverb, and conjunctions
and prepositions, for they are not necessary for the statement's
being" (Kretzmann 1968, p. 13). These are words which do not
have signification in themselves, but only in conjunction with other
significative words, namely the subject and predicate (Kretzmann 1966,
p. 24). Because these words do not have signification in themselves,
they do not have any of the usual properties of terms -- supposition,
copulation, and ampliation. Nevertheless, they still have a
significative function. Explaining this function is the focus of
Sherwood's treatise on syncategorematic terms.



It is in this treatise that we can see evidence for what some have
said is a distinctively English approach to syncategorematic terms
(Uckelman & Lagerlund 2016). Sherwood and his English contemporary
Bacon both consider distributive terms such as 'every' to
be syncategorematic, while in continental works such as those by John
le Page, Peter of Spain, and Nicholas of Paris, distributive terms are
usually considered in summary treatises in the chapter on distribution
(a chapter found in no English summary) (Braakhuis 1981, pp. 138-139).
In his consideration of 'every', Sherwood argues that
propositions involving 'all' require that there be at
least three things for which the predicate term truly stands:



> 
> 
> Rule [II] The sign 'every' or 'all' requires
> that there be at least three appellata (Kretzman 1968, p. 23).
> 
> 
> 



(Remember that an *appellatum* is something which both exists and
which the subject stands for or refers to.) The justification for this
is taken from Aristotle, who Sherwood quotes as saying "Of two
men we say that they are two, or both, and not that they are
all" (Kretzmann 1968, p. 23). That is, if there were fewer than
three, it would be more appropriate to say 'Both' or
'One' rather than 'All'.



Sherwood is also noteworthy for being the first logician we know of to
treat 'is' as a syncategorematic term (Kretzmann 1968, p.
90). He argues that 'is' is equivocal, in that it can
indicate either (1) actual being (*esse actuale*) or (2) habitual
being (*esse habituale*) (Kretzmann 1968, p. 92, Kretzmann 1966,
p. 125; Kretzmann translates *habituale* as
'relational' in Kretzmann 1966 and as
'conditional' in Kretzmann 1968). As a result, the
sentence "Every man is an animal" is ambiguous. When
'is' is taken to indicate actual being, "Every man
is an animal" "is false when no man exists"
(Kretzmann 1968, p. 93). When 'is' is taken to indicate
habitual being, then "insofar as ["Every man is an animal"] is
necessary it has the force of this conditional: 'if it is man it
is an animal'" (Kretzmann 1966, p. 125). In analyzing
universal affirmative categorical sentences in this way, Sherwood can
be seen as an 'early adopter' of our modern truth
conditions for these sentences. A consequence of this view is a
commitment to the existence of *possibilia*, things that could
exist but which do not; such *possibilia* have a diminished sort
of being (*esse diminutum*) (Kretzmann 1968, p. 93). This was an
unusual position in the thirteenth century (Knuuttila 1993), and it
was later denounced by William of Ockham (Freddoso & Schuurman
1980, p. 99).


## 3. Influence



Bacon's approbation of Sherwood is not the only explicit reference we
have to him by his contemporaries. The copy of Chapter Five of the
*Introduction* found in MS Worcester Cath. Q. 13 mentioned
earlier is followed by a collection of anonymous notes (also edited in
Pinborg & Ebbesen 1984 and there called the *Dubitationes*).
Pinborg and Ebbesen argue that these lecture notes, composed either
for a teacher's or a student's use, are unlikely to have been written
in response to lectures given in the 1290s, i.e., when the manuscript
was copied, but rather date from the 1260s or the 1270s, favoring a
date around 1270 (Pinborg and Ebbesen 1984, p. 104). This text thus
provides evidence that Sherwood's works continued to be taught and
circulated.



Beyond these explicit mentions, it is clear that Sherwood's works were
widely influential among logicians at the University of Paris in the
second half of the 13th century. The most direct line of influence
runs from William of Sherwood to his much better-known colleague Peter
of Spain. It was for many years believed that Peter was the first
person to translate Psellus's text (Mullinger 1873, p. 176), prior to
the rediscovery of Sherwood's *Introduction*, which pre-dates
Peter by two decades and which is closer to Psellus's work. Peter's
*Summary of Logic* is clearly indebted to Sherwood. Kretzmann
notes that "many of the features of the *Summulae* that
made it far and away the most popular logic textbook in the Middle
Ages seem quite plainly to have developed as modifications of more
difficult discussions and less felicitous mnemonic devices in the
*Introductiones*" (Kretzmann 1968, p. 6). On the other
hand, Sherwood appears to have been influenced by Peter's treatise on
syncategorematic terms in writing his own; Kretzmann provides a
summary of passages in Sherwood's treatise which "can be read as
allusions to positions taken by Peter" (1968, p. 7). Other
influences can be found in Albert the Great, who used Sherwood's
notion of appellation rather than Peter of Spain's (Kretzmann 1966, p.
5), and Thomas Aquinas, whose analysis of modal propositions follows
Sherwood (Kretzmann 1966, p. 5; Uckelman 2008).


Though Sherwood's indirect influence on the development of logic and semantics, via his influence on Peter of Spain, should not be underestimated, his direct influence beyond the 13th century was more minimal, in part because the influence of Peter of Spain was so great. In the 14th century, any influence Sherwood's approach to the properties of terms might have still had was almost entirely eclipsed by figures such as William of Ockham, John Buridan, and Albert of Saxony (Bos 2011, p. 773).