[*]: Authenticity disputed
strikethrough: Generally agreed to be spurious
De Interpretatione or On Interpretation (Greek: Περὶ
Ἑρμηνείας, Peri Hermeneias) is the second text from
Organon and is among the earliest surviving philosophical
works in the Western tradition to deal with the relationship between
language and logic in a comprehensive, explicit, and formal way. The
work is usually known by its
The work begins by analyzing simple categoric propositions, and draws
a series of basic conclusions on the routine issues of classifying and
defining basic linguistic forms, such as simple terms and
propositions, nouns and verbs, negation, the quantity of simple
propositions (primitive roots of the quantifiers in modern symbolic
logic), investigations on the excluded middle (what to
not applicable to future tense propositions—the problem of future
contingents), and on modal propositions.
The first five chapters deal with the terms that form propositions.
Chapters 6 and 7 deal with the relationship between affirmative,
negative, universal and particular propositions. These relationships
are the basis of the well-known Square of opposition. The distinction
between universal and particular propositions is the basis of modern
quantification theory. The last three chapters deal with modalities.
Chapter 9 is famous for the discussion of the sea-battle. (If it is
true that there will be a sea-battle tomorrow, then it is true today
that there will be a sea-battle. Thus a sea-battle is apparently
unavoidable, and thus necessary. Another interpretation would be: that
we cannot know that which has not yet come to pass. In other words: if
there is a sea battle tomorrow then it is true today that tomorrow
there will be a sea battle. So, only if we can know whether or not
there will be a sea battle tomorrow then can we know if there will be
a sea battle).
Square of opposition
Square of opposition (logical square) and modal logic
4 See also
5 Further reading
6 External links
Aristotle defines words as symbols of 'affections of the
soul' or mental experiences. Spoken and written symbols differ between
languages, but the mental experiences are the same for all (so that
the English word 'cat' and the French word 'chat' are different
symbols, but the mental experience they stand for—the concept of a
cat—is the same for English speakers and French speakers). Nouns and
verbs on their own do not involve truth or falsity.
Chapter 2. A noun signifies the subject by convention, but without
reference to time (i.e. 'Caesar' signifies the same now, two thousand
years after his death, as it did in Roman times).
Chapter 3. A verb carries with it the notion of time. 'He was healthy'
and 'he will be healthy' are tenses of a verb. An untensed verb
indicates the present, the tenses of a verb indicate times outside the
Chapter 4. The sentence is an expression whose parts have meaning. The
word 'man' signifies something, but is not a sentence. Only when words
are added to it do we have affirmation and negation.
Chapter 5. Every simple proposition contains a verb. A simple
proposition indicates a single fact, and the conjunction of its parts
gives a unity. A complex proposition is several propositions
Chapter 6. An affirmation is an assertion of something, a denial an
assertion denying something of something. (For example, 'a man is an
animal' asserts 'animal' of 'man'. 'A stone is not an animal' denies
'animal' of stone').
Chapter 7. Terms. Some terms are universal. A universal term is
capable of being asserted of several subjects (for example
'moon'—even though the Earth has one moon, it may have had more, and
the noun 'moon' could have been said of them in exactly the same
sense). Other terms are individual. An individual or singular term
('Plato') is not predicated (in the same) sense of more than one
A universal affirmative proposition, such as, 'Every man is white' and
a universal negative proposition having the same subject and
predicate, such as, 'No man is white,' are called contrary. A
universal affirmative proposition ("Every man is white") and the
non-universal denial of that proposition in a way ("Some man is not
white") are called contradictories. Of contradictories, one must be
true, the other false. Contraries cannot both be true, although they
can both be false, and hence their contradictories are both true (for
example, both, 'Every man is honest,' and 'No man is honest,' are
false. But their contradictories, 'Some men are not honest,' and,
'Some men are honest,' are both true.
Chapter 8. An affirmation is single, if it expresses a single fact.
For example, 'every man is white'. However, if a word has two
meanings, for example if the word 'garment' meant 'a man and a horse',
then 'garment is white' would not be a single affirmation, for it
would mean 'a man and a horse are white', which is equivalent to the
two simple propositions 'a man is white and a horse is white'.
Chapter 9. Of contradictory propositions about the past and present,
one must be true, the other false. But when the subject is individual,
and the proposition is future, this is not the case. For if so,
nothing takes place by chance. For either the future proposition such
as, 'A sea battle will take place,' corresponds with future reality,
or its negation does, in which case the sea battle will take place
with necessity, or not take place with necessity. But in reality, such
an event might just as easily not happen as happen; the meaning of the
word 'by chance' with regard to future events is that reality is so
constituted that it may issue in either of two opposite possibilities.
This is known as the problem of future contingents.
Aristotle enumerates the affirmations and denials that can
be assigned when 'indefinite' terms such as 'unjust' are included. He
makes a distinction that was to become important later, between the
use of the verb 'is' as a mere copula or 'third element', as in the
sentence 'a man is wise', and as a predicate signifying existence, as
in 'a man is [i.e. exists]'.
Chapter 11. Some propositions appear to be simple which are really
composite. A truly single proposition the name of the subject combines
to form a unity. Thus 'two-footed domesticated animal' means the same
thing as a 'man', and the three predicates combine to form a unity.
But in the term 'a white walking man' the three predicates do not
combine to form a unity of this sort.
Chapter 12. This chapter considers the mutual relation of modal
propositions: affirmations and denials which assert or deny
possibility or contingency, impossibility or necessity.
Chapter 13. The relation between such propositions. Logical
consequences follow from this arrangement. For example, from the
proposition 'it is possible' it follows that it is contingent, that it
is not impossible, or from the proposition 'it cannot be the case'
there follows 'it is necessarily not the case'.
Chapter 14. Is there an affirmative proposition corresponding to every
denial? For example, is the proposition 'every man is unjust' an
affirmation (since it seems to affirm being unjust of every man) or is
it merely a negative (since it denies justice).
Square of opposition
Square of opposition (logical square) and modal logic
The logical square, also called square of opposition or square of
Apuleius has its origin in the four marked sentences to be employed in
syllogistic reasoning: Every man is white, the universal affirmative
and its negation Not every man is white (or Some men are not white),
the particular negative on the one hand, Some men are white, the
particular affirmative and its negation No man is white, the universal
negative on the other.
Robert Blanché published with Vrin his book
Structures intellectuelles in 1966 and since then many scholars think
that the logical square or square of opposition representing four
values should be replaced by the logical hexagon which by representing
six values is a more potent figure because it has the power to explain
more things about logic and natural language. The study of the four
propositions constituting the square is found in Chapter 7 and its
appendix Chapter 8. Most important also is the immediately following
Chapter 9 dealing with the problem of future contingents. This chapter
and the subsequent ones are at the origin of modal logic.
Aristotle's original Greek text, Περὶ Ἑρμηνείας (Peri
Hermeneias) was translated into the
Latin "De Interpretatione" by
Marius Victorinus, at Rome, in the 4th century.
Another translation was completed by
Boethius in the 6th century, c.
J. L. Ackrill (ed.), Aristotle, Categories and De Interpretatione:
Translated with Notes and Glossary. Oxford: Clarendon Press, 1963.
Hans Arens (ed.), Aristotle's Theory of Language and Its Tradition.
Texts from 500 to 1750, Amsterdam: Benjamins, 1984.
Susanne Bobzien, 'Aristotle's
De Interpretatione 8 is about
Ambiguity', in Maieusis: Essays on Ancient Philosophy, Oxford: Oxford
University Press, 301-322 (2007).
Deborah Modrak, Aristotle's Theory of Language and Meaning, Cambridge:
Cambridge University Press, 2001.
Jean-François Monteil, La transmission d’Aristote par les Arabes à
la chrétienté occidentale: une trouvaille relative au De
Interpretatione, Revista Española de Filosofia Medieval 11: 181–195
Jean-François Monteil, 'Isidor Pollak et les deux traductions arabes
différentes du De interpretatione d’Aristote', Revue d’Études
Anciennes 107: 29–46 (2005).
Jean-François Monteil, Une exception allemande: la traduction du De
Interpretatione par le Professeur Gohlke: la note 10 sur les
indéterminées d’Aristote, Revues d'Études Anciennes 103:
C. W. A. Whitaker, Aristotle's De interpretatione. Contradiction and
Dialectic, Oxford: Clarendon Press, 1996.
Works related to
De Interpretatione at Wikisource
Text of On Interpretation, (in html, epub or mobi format) as
translated by E. M. Edghill
Aristotle's De Interpretatione: Semantics and Philosophy of Language
with an extensive bibliography of recent studies
The Master Argument: The Sea Battle in De Intepretatione 9, Diodorus
Cronus, Philo the Dialectician with a bibliography on Diodorus and the
problem of future contingents
Sea Battle Hub, a tutorial introduction to the discussion of the truth
status of future events from
De Interpretatione 9.
On Interpretation public domain audiobook at LibriVox
Jules Vuillemin, "Le chapitre IX du
De Interpretatione d'Aristote –
Vers une réhabilitation de l'opinion comme connaissance probable des
choses contingentes, in Philosophiques, vol. X, n°1, Apri