[4.18.1] Ockham on Mental Language

William Ockham (1285-1349 AD) in Summa of Logic and Quodlibet writes about the mental language and its relation to written and spoken language (see also [4.0.1]):

  • Concepts (mental terms) are acts of understanding of objects.
  • Concepts, through their likeness to objects, signify those naturally. Because of this, we say that mental language is natural.
  • The mind combines concepts into mental propositions; both are mental expressions and part of the mental language.
  • Concepts can be mental names, verbs, adverbs, conjunctions, propositions.
  • Concepts are non-accidental, meaning that names don’t have case, number, comparison, gender, declension, and verbs don’t have mood, voice, person, number, tense, conjugation, inflection.
  • Spoken terms (utterances) signify concepts conventionally.
  • Spoken terms can be combined into spoken propositions; both are spoken expressions and part of the spoken language.
  • Spoken expressions signify (or are subordinated to) mental expressions through language-specific conventions; this is why the spoken and written language is conventional language. This spoken expression – mental expression signification makes possible the translation between languages.
  • Spoken expressions are synonyms if we have a many-to-one signification relation to mental expressions, and equivocals if we have a one-to-many signification relation to mental expressions.
  • Written terms signify conventionally spoken terms. We can model the written language with similar classes as for the spoken language.

The following OntoUML diagram presents the main classes of Ockham’s theory of mental language.

Ockham on mental language

The following OntoUML diagram pictures the main classes of Ockham’s model of mental language:

ObjectAn object, a thing or state of affairs in the external world.
TermTerm generalizes the properties os concepts, utterances and inscriptions.generalizes Concept; SpokenTerm, WrittenTerm
ConceptA concept [mental term] is an act of understanding of the Object signified:
“There was a great disagreement in the Middle Ages about what it is that linguistic units signify, but there was universal agreement over the Aristotle tells us that although spoken and written terms differ from linguistic community to linguistic community, mental terms or concepts (as Boethius interpreted the passage) do not. They ‘are the same for all.’
This doesn’t mean that everyone has exactly the same supply of concepts, since that’s plainly not so; we think about and know about different things. […] it means is that, for example, my concept 'man‘ and your concept 'man‘ differ only ‘numerically,’ as they said. That is, they are exact duplicates of one another. They do not differ in the way the English spoken word ‘man’ differs from the Latin spoken word ‘homo’ or from the Greek spoken word ‘ἄνθροπος’, which are more than numerically different. (They don’t sound at all alike.) In short, what Aristotle is saying in this text is that, while we may speak and write in different languages, we all think in the same language.
[…] Concepts are private and mind-dependent”
subkind of MentalExpression; signifies naturally the Object; shared part of MentalProposition and MentalLanguage
Non-accidentalConcepts are non-accidental:
“While Ockham says that mental language reflects spoken and written language to the extent that it too has parts of speech, and even (apart from the two doubtful cases we have just discussed) the same parts of speech, nevertheless there are other grammatical features of spoken and written language that do not carry over into mental language [namely in concepts].
Here Ockham’s Quodlibet 5, q. 8, gives the fuller account. In that question he distinguishes two main kinds of grammatical ‘accidents’ — that is, grammatical properties — of spoken (and written) words: ‘common’ accidents and ‘proper’ ones.”
Common grammatical accidents for names are: case, number, comparison, quality.
Proper grammatical accidents for names are: gender, declension.
Common grammatical accidents for verbs are: mood, voice, person, numer, tense.
Proper grammatical accidents for verbs are: conjugation, inflection.
characterizes Concept
Likeness“Aristotle tells us […] that concepts or mental terms are likenesses of real things and that real things are just what they are, the same for everybody. A stone is just a stone, and that’s the end of the matter. It doesn’t change its structure or nature depending on who’s thinking about it. It is “objective” in the sense of being interpersonally invariant. We all therefore live in the same world, ontologically speaking. There is no room for any sort of “ontological relativity” (to use Quine’s phrase) in this Aristotelian doctrine.
Now concepts, Aristotle has just told us, are likenesses of these interpersonally invariant things. That is, the relation between a concept and what it is a concept of is a relation of similarity or likeness. […]
Here let’s just explore some of the consequences of the doctrine. Similarity, when it occurs, is an objective fact. There is nothing conventional about it at all. (Of course, it may be a matter of convention or cultural conditioning which similarities matter to us, or which ones we notice. But that is an altogether different question.) If Socrates and Plato, for example, are alike to the extent that they are both over six feet tall, then that fact does not depend on anyone’s convention; it is, so to speak, a fact of ‘nature.’”
relates Concept with Object
MentalProposition“Ockham many times says explicitly that mental propositions are composed, made up, of mental terms — that is, of concepts. He says it for example in Summa of Logic I.1, § 6:
‘A conceived term is an intention or passion of the soul naturally signifying or consignifying something [and] apt to be a part of a mental proposition…’
[…] This is clear from the fact that for every spoken expression, true or false, there corresponds some mental proposition put together out of concepts. Therefore, just as the parts of the spoken proposition that are imposed to signify things on account of the necessity of signification or expression (for it is impossible to express all [things] by means of verbs and names alone that can be expressed by means of [them together with] the other parts of speech) are distinct parts, so [too] the parts of the mental proposition that correspond to utterances are distinct, to make distinct true and false propositions.”
subkind of MentalExpression; shared part of MentalLanguage
MentalExpressionMental expressions are concepts and mental propositions.
MentalLanguage“Ockham says that there are parts of speech in mental language just as in spoken language — nouns, verbs, adjectives, prepositions, etc. […]”
Natural“What is the most basic feature that distinguishes mental language from spoken or written language? Answer: Mental language is supposed to be a natural language, whereas spoken language and written languages are conventional. To say that mental language is “natural” is to say that its features are not established by choice or convention, but by nature. They’re not up to us.” characterizes MentalLanguage
MentalName; MentalVerb; MentalAdverb; MentalConjunction; MentalPreposition“As for the first point, I say that just as among spoken and written terms some are names, [while] others [are] verbs, others pronouns, others participles, others adverbs, others conjunctions, [and] others prepositions, so [too] among mental concepts some concepts are [mental] names, others [are] [mental] verbs, others [mental] adverbs, others [mental] conjunctions, [and] others [mental] prepositions.”Subkind of Concept
SpokenTermA spoken term signifes conventionally a Concept. subkind of Term; signifies conventionally Concept
SpokenName; SpokenVerb; SpokenPronoun; SpokenConjunction; SpokenAdverb; SpokenPartciple; SpokenPreposition “As for the first point, I say that just as among spoken […] terms some are [spoken] names, [while] others [are] [spoken] verbs, others [spoken] pronouns, others [spoken] participles, others [spoken] adverbs, others [spoken] conjunctions, [and] others [spoken] prepositions […]”subkinds of SpokenTerms
ConventionA spoken expression signifies a mental expression by convention:
“we will also see authors talking about the signification of words and inscriptions as conventional (= ad placitum, literally “at your pleasure”) signification. So too, we will see people refer to spoken and written language as a whole as artificial or conventional, in contrast to mental language, which is natural. […] The conventions can be changed, with the result that there are different languages over time. And for that matter the conventions can vary at any one time, so that there are several distinct languages all coexisting simultaneously (like English and French).”
relates SpokenExpression with MentalExpression
Synonim “The term ‘rock’ and the term ‘stone’, let us say, are synonyms. They are subordinated to the same concept, which is a natural likeness of all stones (rocks) in the relevant sense […]
In short, where the subordination relation is many-one, we have synonymy.
[…] It is this fact that accounts for the possibility of translating from one language to another. Insofar as a translation is supposed to ‘express the same thought’ as the original, we can say that a statement in one language is a correct translation of a statement in another language iff the two statements are subordinated to the same mental proposition.
This suggests that mental language can provide us with a general account of synonymy, not only of interlinguistic synonymy (as with translation) but of intralinguistic synonymy too. Two expressions — whether terms, whole propositions or whatever, whether from different languages or from the same language —
are synonymous iff they are subordinated to the same mental expression. […]
role of SpokenExpression; relates materially to MentalExpression
SynonimitySynonimity relates Synonim with mental expression. relates Synonim with MentalExpression
Equivocal“Ockham says in his Summa of Logic I.3, § 3:
Now an utterance is ‘equivocal’ if it signifies several [things and] is not a sign subordinated to one concept, but is instead a sign subordinated to several concepts or intentions of the soul.
Thus a spoken (and presumably also a written) expression is equivocal iff it is subordinated to more than one mental expression. Ockham goes on to say this holds not only for intralinguistic equivocation, but also for interlinguistic equivocation. It is a little hard to think of good examples of interlinguistic equivocation, but for spoken language consider the Latin ‘homo’ (= man) and the Greek prefix ‘ὁμο-’ (= the same). For written language, consider the sentence ‘Jam dies’. In English it affirms the mortality of that sweet substance one spreads on toast. (It’s an odd thing to say, of course, but that doesn’t matter here.) In Latin it says ‘Now it is day.’ In short, where the subordination relation is many-one, we have synonymy. Where it is one-many, we have equivocation.”
[…] Ockham’s text in Summa of Logic I.13, rules out equivocal terms in mental language, it says nothing at all about mental propositions.”
role of SpokenExpression; relates materially to MentalExpression
EquivocationEquivocation relates synonim with mental expression. relates Equivocal with MentalExpression
SpokenPropositionSpoken propositions are composed of spoken terms, namely spoken names, verbs, pronouns, conjunctions, adverbs, partciples and prepositions. shared part of SpokenLanguage
SpokenExpressionSpoken expressions are spoken terms and spoken propositions.signifies conventionally MentalExpression
SpokenLanguage“Ockham says (§ 1) that there are parts of speech in mental language just as in spoken language — nouns, verbs, adjectives, prepositions, etc. He says the same thing […]:
As for the first point, I say that just as among spoken and written terms some are names, [while] others [are] verbs, others pronouns, others participles, others adverbs, others conjunctions, [and] others prepositions, so [too] among mental concepts some concepts are names, others [are] verbs, others adverbs, others conjunctions,
[and] others prepositions.
WrittenTermA written term signifies conventionally a spoken term. We can model the written language with the same class structure as the spoken language. signifies conventionally the SpokenTerm


First published: 13/9/2021

[4.0.2] Medieval Theory of Supposition (Reference)

William Ockham (1285-1349 AD), Walter Burley (1275–1344 AD), John Buridan (1301-1358 AD), and other medieval philosophers worked out many versions of the theory of supposition (reference):

  • Propositions (sentences) are made up of terms.
  • Terms in a proposition refer to other terms – the suppositum (or supposita); this relation is called supposition. The supposition of a term always occurs in a propositional context and can be entirely different from its signification (see [4.0.1]).
  • Medieval philosophers elaborated complex categorizations for the relation of supposition. For example, Ockham and Burley, on the first level, divides suppositions into suppositions proper and improper.
  • Proper suppositions for most authors on a second level are divided into the material, simple and personal. 
  • More levels of different sub-divisions were elaborated by other medieval authors. 

The following OntoUML diagram pictures the main classes of the medieval theory of supposition.

Medieval theory of supposition

PropositionA proposition or sentence is made up of terms.
TermA mental, spoken, or written term.member of Propositon
SuppositumSuppositum is “whatever a term supposits for.” role of Term
Supposition“What sort of relation is supposition? Well, the first thing we can say about it is that supposition is a semantic relation. To a first (but pretty good) approximation, supposition in this first part of the theory is what nowadays we call ‘reference.’ It is the relation between the terms used in a proposition and the things those terms are used to talk about in that proposition. […]
supposition occurs only in a propositional context. And this is the first main difference between supposition and signification, which can occur outside a propositional context according to almost any author.
The second main difference is this: We do not always in practice use terms in propositions to talk about what those terms signify. We use them in a variety of other ways too. Hence supposition also differs from signification insofar as a term may signify one thing, but supposit on a given occasion for something entirely different.”
relates Suppositum with Supposita
ImproperSupposition“Ockham describes the difference between the two near the very end of the first part of the Summa logicae:
‘Now you need to know that just as proper supposition occurs when a term supposits for what it properly signifies, improper supposition occurs when a term is employed improperly.’
This borders on tautology, and is not much help. As we shall see shortly, it is a very careless way of putting the matter. Burley’s way of stating the distinction is somewhat less precise, but at least not positively objectionable. Here is what he says in Purity, § 8:
‘By its first division, supposition is divided into proper and improper supposition. Supposition is proper when a term supposits for something for which it is permitted to supposit literally. Supposition is improper when a term supposits for something by transumption or from its usage in speech.’
Improper supposition therefore is the kind of supposition or reference a term has when it is used figuratively and not literally.
Now a detailed semantics of metaphor was just as much beyond the reach of mediaeval authors as it is beyond our reach today. So we should not be surprised to find that the theory of improper supposition is not worked out very fully.”
subkind of Supposition
ProperSuppositionproper supposition occurs when a term supposits for what it properly signifiessubkind of Supposition
MaterialOckham defines it material supposition (Summa of Logic I.64, § 10) as follows:
Material supposition occurs when a term does not supposit significatively but supposits for an utterance or for an inscription.
Notice that if the phrase ‘taken significatively’ does not mean what I have claimed it does, then on any other reasonable interpretation the term ‘utterance’ could never be in material supposition.
As an example of material supposition, consider the proposition ‘Man is a monosyllable’. In the sense in which that proposition is true, the term ‘man’ supposits not for individual men, and not for the concept to which it is subordinated, but for itself. And, since it is not taken significatively there, it follows that the term is in material supposition.”
subkind of ProperSupposition
Simple“Ockham defines simple supposition as follows (Summa of Logic I.64, § 8):
Simple supposition occurs when a term supposits for an intention of the soul, but is not taken significatively.
There’s that phrase ‘taken significatively’ again. Notice that if it does not mean what I think it does, then on the other interpretation the term ‘concept’ could never be in simple supposition. And that will turn out not to be so.
Let me give you an example of the kind of thing Ockham has in mind for simple supposition. For Ockham, recall, there are no real universals or common natures. The only universals for him are universal concepts. And even they are not universal in the sense of being metaphysically shared by many things, as realists
want universals to be. They are universal only in the sense that they are concepts of many things — they are “general” concepts. Metaphysically, they are just as individual as anything else; they are individual thoughts. They are not universal in the sense of being “in many”; they are universal only in the sense of being “predicated of many.” Ockham interprets talk about species and genera as referring to these general concepts, since they are the only plausible candidates, given his ontology.
Hence for Ockham, in ‘Man is a species’, in the sense in which it is true, the subject term supposits not for some extramental universal or common nature that is the species, but rather for the concept of man, which is a specific concept.
Now notice: In that proposition the term ‘man’ supposits for an intention of the soul, but it is not taken significatively, since it does not supposit for men there, but for the concept. Hence it is in simple supposition.”
subkind of ProperSupposition
PersonalOckham defines personal supposition (Summa of Logic I.64, § 2) as follows:
“Personal supposition, in general, is that [which occurs] when a term supposits for its significate, whether that significate is (a) a thing outside the soul, whether it is (b) an utterance, or (c) an intention of the soul, whether it is (d) an inscription, or anything else imaginable. So whenever the subject or predicate of a proposition supposits for its significate in such a way that it is taken significatively, the supposition is always personal.
And he goes on to give some examples of the various possibilities he lists (ibid., §§ 3–6):
(a) In ‘Every man is an animal’, ‘man’ supposits personally for
a thing outside the soul.
(b) In ‘Every spoken name is a part of speech’, ‘name’ supposits
personally for utterances.
(c) In ‘Every intention of the soul is in the soul’, ‘intention of
the soul’
supposits personally for intentions of the soul.
(d) In ‘Every written word is a word’, ‘written word’ supposits
for inscriptions.

In each case, the term refers to or supposits for the things it (primarily) signifies, the things it is truly predicable of, and so is in personal supposition. […] A term is taken significatively if and only if it is taken for (supposits for) everything it primarily signifies.”
subkind of ProperSupposition


First published: 26/8/2021