INTRODUCTION TO JEAN BURIDAN’S LOGIC
1. Jean Buridan: Life and Times
Buridan is best-known to philosophers for the example of “Buridan’s
Ass,” starving to death between two equidistant equally tempting bales of
hay, who appears in Spinoza, Ethica II, scholium to Proposition 49. But
this poor fragment of Buridan’s great reputation is as apocryphal as his sup-
posed amorous adventures with the Queen of France, famous from Fran¸
Villon’s poem “La testament,” or his founding the University of Vienna:
ded with asses.
Our knowledge of Buridan’s life is sketchy.
We know that he was
French, but little else about his background; various examples in his writings
suggest a man familiar with Picardy. Just as we do not know where Buridan
was born, we do not know when he has born. He must have been born by
1300, but this is the only reliable inference we can make.
Buridan is ﬁrst glimpsed in the pages of history in 1328, the rector of
the University of Paris, vir venerabilis et discretus, presiding over a debate
that took place on February 9. The next year, on 30 August 1329, he
received a beneﬁce from Pope John XXII; on 2 November 1330 he received
another beneﬁce from the same Pope, who addressed him each time as a
Master of Arts. We then lose sight of him until 25 September 1339, when
Buridan was a signatory to a condemnation of certain doctrines (supposedly
including those of William of Ockham); during this period he received an
expectation of a prebend from Pope Benedict XII. In 1340 he was again
rector of the University of Paris.
The last time he graces the pages of
history is as a ﬁgure signing a border treaty under the authority of the
University, on 12 July 1358.
All translations are mine. See the Bibliography for abbreviations, editions, and refer-
given punctuation and capitalization.
Unless one identiﬁes Plato as Buridan’s Ass: “He [Plato] said that if I am indiﬀerent
reason I go to the left, and conversely; therefore, either I go to each [direction], which
is impossible, or I go to neither until another determining suﬃcient cause comes along”
(QM 6.5 ﬀ. 35vb–36ra).
The classic biographical work is Edmond Faral , the source of the factual knowl-
– 1 –
From several remarks (e. g. TC 3.4.14) we know Buridan spent his
life as a career Master in the Faculty of Arts—a rarity, for the Faculty of
Arts was generally made up of students who were going on to advanced
study in theology, and there was a fast turnover.
These few facts are all we know of Buridan’s life. Yet we possess his
works (in large measure), and in them there is a wealth of material for the
philosopher. Buridan’s inﬂuence and reputation were immense, both during
his life and for centuries afterwards. He was known for his contributions to
ethics, physics, and, perhaps most important, for his philosophy of logic.
It is the latter to which this introduction and the translations are devoted.
Buridan’s mediæval voice speaks directly to modern concerns: the attempt
to create a genuinely nominalist semantics; paradoxes of self-reference; the
nature of inferential connections; canonical language; meaning and refer-
ence; the theory of valid argument. It is to be hoped that Buridan can
reclaim his lost reputation among contemporary philosophers for his pene-
trating and incisive views on these and other matters.
2. Buridan’s Treatises
The “Treatise on Supposition” [TS] is the fourth treatise of a much
longer work known as the Summulae de dialectica, the contents of which
Buridan himself describes in the beginning of the ﬁrst chapter of the ﬁrst
We divide this work into nine treatises, of which the ﬁrst will be
about sentences and their parts and passions; the second about
the predicables; the third about the categories; the fourth about
supposition; the ﬁfth about the syllogism; the sixth about dialectical
lock; and the seventh about fallacies. An eighth [treatise] about
division, deﬁnition, and demonstration is added, which our author
did not deal with in his book; the ninth will be about the practice
of sophisms—but in my lectures I shall not follow the other lectures
with this last treatise.
“Our author” is Peter of Spain,
and “his book” is the Summulae logicales.
reason he states in the last sentence of the Proemium to the Summulae de
Wishing to say certain general things about the whole of logic with-
out excessively painstaking investigation, I shall particularly rely
The edition of Peter of Spain I have used to check against Buridan’s text—the points
c Peter King, from Jean Buridan’s Logic (Dordrecht: D. Reidel 1985) 3–82.
upon the brief treatise of logic the venerable Doctor, master Peter
he wrote and said in another way when at times it seems to me
The Summulae de dialectica is written as a commentary on Peter of Spain.
But there were topics Peter of Spain said little or nothing about; and some-
times what he did say Buridan regarded as hopeless. In the former case
Buridan wrote an independent treatise, as he remarks for the eighth and
ninth treatises listed. In the latter case Buridan simply jettisons the text
written by Peter of Spain and substitutes his own text, commenting upon
it. Such a case is the fourth treatise, the treatise on supposition.
The Summulae de dialectica is one of two or three major logical
works we have of Buridan’s: the ninth treatise seems to have been consid-
ered an independent work, called the Sophismata.
The other work is the
investigation in logic. If TS was the textbook for Buridan’s introductory
course on logic, TC is a handbook to the logic graduate seminar. The rest
of Buridan’s works on logic are quaestiones on the standard logical corpus:
Porphyry’s Isagoge, and Aristotle’s Categories, De interpretatione, Prior
Analytics, Posterior Analytics, Topics, and Rhetoric.
For TS I have used the edition of the text given by Maria Elena Reina
storia della ﬁlosoﬁa (1959) 175–208 and 323–352. For TC I have used the
edition of the text given by Hubert Hubien, Iohannis Buridani tractatus de
Edition critique, in the series Philosophes m´
e de Louvain 1976. Divergences from these texts are noted in the
translation where they occur.
3. Meaning and Mental Language
3.1 Levels of Language
Buridan and other logicians of the fourteenth century were inspired
by a remark Aristotle made in De interpretatione 1 16
There is a modern edition of this work (although not a genuinely critical edition) in
Soph. 8, has been newly edited and translated in Hughes . Buridan’s references
to the Sophismata in TS
are not consistent: they are future and past, frequently
within a short compass—see e. g. TS 3.7.16 (past) and 3.7.23 (future).
Faral  496 lists several lost works of Buridan that probably dealt with logic: De
I have not translated Aristotle’s original Greek, but rather the Latin version given by