Macquarie University
PHIL360 Later Medieval Philosophy


Copyright © 1996 R.J. Kilcullen

This is cassette 6.

(To follow this lecture you will need to have before you A. Hyman and J.J. Walsh (eds.), Philosophy in the Middle Ages (Hackett, Indianapolis, 1973), pp. 582-9, and a printout of Duns Scotus, Ordinatio, II, dist. 3, pars 1, q. 5 and q. 6.)

We come now to Scotus's theory of universals or of individuation. This is the subject of Opus Oxoniense, book 2, distinction 3, extracts from which are in Hyman and Walsh. The first question is, in effect, whether any theory of individuation is needed. Aren't real things individual "from themselves", just by being real? The Latin says: ex se, sive ex natura sua, "from (or out of) itself, or from its nature". Elsewhere he uses as equivalent per se and de se. Se means itself, ex means from or out of, per means through, de means of or by or from. So the question is whether an individual thing gets it singularity or individuality from itself, not from anything else.

Remember from Boethius and Abelard in PHIL252 the contrast between individuality and universality, a contrast that goes back to Plato's theme of "one and many". There are many individual human beings, and we can say of each of them "This is a human being", "That is a human being", "This other is a human being", and so on - the same predicate, "a human being", occurring in each proposition. Something thus predicable of many individuals is a universal.

Let us now read first the preliminary pro and con arguments. Read p.582, first three paragraphs. Pause the tape while you read this.

The two arguments "on the contrary" require some comment: they suppose that there are in nature, in the real world, species of things, all the members of which share the same nature; e.g. there are many individual human beings, all of which share in the same real nature, being human, and there are many stones, all of which share the nature of stone. If such a nature were intrinsically, from itself, singular then there would be only one instance of that one nature, human being or stone. Whatever that nature was in, would be this human being or stone - there would not be many instances, only one.

The opinion that no theory of individuation is needed

After the preliminary exchange of short arguments, Scotus presents the opinions of others followed by criticisms. Beside the next paragraph, "Here it is said", (i.e. by someone else), write "another opinion" and on p.583, near the bottom, at the paragraph that begins "In reply to the question", write "His own opinion". At the bottom of p.584, beside "But against this" write "objections". On p.584, three quarters of the way down, beside "And through this" write "Answer to arguments at the beginning".

Now go back to p.582 and read the paragraph beginning "Here it is said". I don't know whose opinion this was; perhaps Scotus invented it. Ockham will later adopt it. What it says is that there is no need for a theory of individuation, what we need is a theory of universality. "It is not necessary to seek a cause of singularity other than the cause of the nature"; i.e., whatever efficient cause, formal cause, material cause etc. produce a human being, produce an individual human being. "What is to be sought is the cause whereby a nature is universal", i.e. the cause that explains how human nature exists as a universal predicable of many individuals; and that cause is the intellect. The world consists of real things each of which is individual just by being real; whatever causes the thing causes it as an individual. We then come along and abstract in our minds the natures that we see, by comparison, to be found in sets of real things. The phrase "dependent existence" is in Latin esse secundum quid, more literally "being from some special point of view". The contrast is with being simpliciter, or "unqualified being" (as this translation says). Being in the soul is not being simpliciter, being without qualification, but only being in a special sense.

Now read the criticism of this opinion, on p.583. Some comments. In p.583 line 2, change "prior to its act" to "prior to the act", meaning to the human act (in this case of knowing) of which it is the object; cf. "the act" in p.583 line 6, also the act of knowing. In line 5 "its own" means the object's own. "According to you" (line 2) is Scotus's usual way of arguing as if he is addressing the holder of the other opinion. His argument is this. When we know some object, what we know is true before we know it - not necessarily "before" in time but "before" in the sense that it is logically presupposed: we can't know something unless it is so. So the first argument is that according to you (the holder of the opinion under examination), the nature prior to our knowing it is singular, so if we know it as a nature common to many individuals we are "knowing" it as opposite to what it is, namely singular (which is not knowledge, since it is false).

The next argument ("Besides") turns on the notion of "less than numerical unity". Let me explain. Numerical unity is what each countable unit has - we can count individuals, so that Socrates, Plato, Aristotle, are three: each of these three has numerical unity. On the other hand, people sometimes speak of the unity of a species - Socrates, Plato and Aristotle are three individuals, but they share the one nature, belong to the one species. The unity of a species Scotus calls less-than-numerical: he orders unities from individual, to specific, to generic, to categorical (all substances have in common that they are substances). As we go up the levels of Porphyry's tree, we move from the highest degree of unity, numerical, to progressively lesser degrees of unity: the wider the class and the more diversity there is among its members, the less its degree of unity.

There is a textual problem at the beginning of this paragraph. Literally Scotus says: "Of whatever the real proper and sufficient unity is less than numerical unity, that is not of itself one with numerical unity, or is not of itself 'this'". This is not quite grammatical, but the meaning is clear enough: If the real proper and sufficient unity of X is less than numerical unity, then X is not numerically one of itself. So he is not saying that it is universally true, of anything whatsoever, that its real proper and sufficient unity is less than numerical: this is false - the proper unity of Socrates, for example, is not less than numerical, but numerical. What he is saying is that if the proper unity of X (e.g. of human nature) is less than numerical, then X (human nature) is not of itself individual. There is another textual problem in line 6. Read: "For if the proper unity [i.e. "its own" unity], which is due to something of itself, is less than" etc.

Read the rest of the paragraph.

At the end of this paragraph he refers to "unity of reason". This expression is like "distinction of reason" - "of reason" here means imposed by the mind on a world in which it is not really there. So he is saying that if numerical unity is the only real unity, then the unity of a species or genus will be an invention of our minds, something we impose on the world. But the consequent (i.e. the "then" clause) is false - the unity of a species or genus is real (genuine), not just an invention of our minds. He says he will prove this in five or six ways. In fact he gives seven arguments (Scotus was still re-writing this work). Hyman & Walsh include the second, sixth and seventh. Read the second, which begins "Besides, secondly".

Some changes to the text. In the second and third lines, for "an atom" etc., substitute: "In an atomic species comparison takes place, because there is one nature; but not in a genus". "Atom" in Greek means not cut, not divided. An "atomic" species means an ultimate species, a species not also a genus, one that is not further sub-divided into species. Is the human race an atomic species? If you think that the various races and types of human beings differ only accidentally or inessentially, that they all share the same human nature, then you are saying that the human species is atomic. In an atomic or ultimate species, Aristotle says, comparison takes place, but not in a genus. The reference is to Aristotle Physics VII.4, 249 a5 ff. An example he gives there may explain the point: "We cannot say that one is more coloured than the other where only colour in general and not any particular colour is meant; but they are commensurable in respect of whiteness". White, red, blue, etc., are species of colour; colour in general is the genus; you can't say that some coloured thing is more coloured (the genus), but you can say that, in comparison with another coloured (white) thing, one is more white (the species). So comparison (in the sense of ranking) as more or less can take place in the species, but not in the genus. Then Scotus argues: "this true unity" (i.e. the unity an atomic species has that a genus does not have) "is not a unity of reason" - i.e. a unity imposed by us, by our grouping things together under one concept, "since the concept of a genus is just as much one", since we also group things into genera under a single concept. Otherwise, if the concept of a genus were in fact a collection of different concepts - for example, if the concept of animal were simply the set of the many concepts of dog, horse, human being, etc., - then when we said "A horse is an animal" we would really just be saying "A horse is a horse", since horse would be the applicable one of the set of concepts of animal. As Scotus says (eighth line of this paragraph) "the same would be predicated of itself", "A horse is a horse". When Aristotle says that the unity of an atomic species permits comparisons of more and less whereas a genus does not have unity enough for that, he is not talking about unity of concept (a unity of reason) but about some sort of real unity - the real unity of a specific nature. This brings us to the second last line of the paragraph. Put in a full stop and begin a new sentence with "but he did not intend"; this is a different point. And change the last line: "in a numerical unity there is no comparison". He means that a specific nature has a certain real unity that a genus does not have. But, on the other hand, he does not mean that it is one with numerical unity - that would be too much unity: in a numerical unity there is no comparison of more and less; if two white things were in fact one numerically you could not say that one was more white than the other. So a species, such as white things, must have a certain real unity greater than the unity of a genus, yet less than numerical unity.

Now read the paragraph beginning "Again, sixthly". In line 1 before "unity" insert "real". Change the semicolon in line 3 to a comma, since the reason why the consequent is false is not just the first clause but the rest of the paragraph; in the next line change "can" to "could". This argument is clear enough, and pretty telling. If the only real unity were the numerical unity of individuals, then species and genera would have no real unity, groupings would be arbitrary.

Read the next paragraph, "Again seventhly". Some changes to the text. Read: "If [i.e. even if] no intellect existed, fire would generate fire and would destroy water, and there would be a real unity of generator to generated according to form because of which there would be univocal generation", etc. In Aristotle's physics not all generation is univocal. Aristotle thought that sunlight could generate worms in suitable matter, but there is no resemblance, no sharing of form, between the sun and the worms. In other cases, however, generator and generated have the same form, as for example when fire causes fire or a human being generates a human being. And this would be true, Scotus says, even if no intellect existed: the unity of generator with generated in cases of univocal generation is real, not something imposed or invented by our intellect. The point, once again, is that there are unities between numerically distinct individuals (the generator and the generated) which are not arbitrarily imposed on invented by our minds.

Duns Scotus's doctrine of the "common nature"

This brings us to his answer, "In reply to the question". At the bottom of p.584, beside "But against this there seem to be two objections" write "Objections", and read to this point from the bottom of p.583. Some comments on the text: In the first line of p.584, "characteristic" translates ratio, and on line 2 "understanding" also translates ratio. Ratio here means conception. So substitute: "unless it is understood under a conception repugnant with the [true] conception of such an object". "Characteristic" elsewhere on this page also means conception or true conception.

In line 14 of p.584, "intrinsic" translates per se, literally "through itself". Two lines down insert per se after "true" - "true per se in the primary way". In the next line insert per se after predicated. Scotus is referring to the first of the modes of perseity distinguished in Aristotle Posterior Analytics I.4. A proposition is true per se in the first mode if its predicate is part of the definition of its subject - e.g. "socrates is rational". In the line in which you just made an insertion, line 17, change "accepted" to "taken" - "of a quiddity taken that way".

This page is mostly a discussion of Avicenna's dictum that horseness (the nature of horses) is just that nature and is not of itself one or many, universal or particular. Scotus refers to a natural priority (7 lines down in this paragraph: "it is naturally prior to all"). Imagine instants or moments, not of time but "of nature": i.e. we are not talking about a temporal sequence but about a metaphysical order. (Imagining "instants of nature" is a favourite Scotist device, severely criticised by Ockham.) In the first instant of nature the nature of horses is just whatever its definition expresses; in the second moment it is determined to one or other of two modes of existence, either in the mind or outside the mind. As determined to extramental existence it is, or can be, numerically many (since in extramental reality there are, or can be, many horses); as determined to existence in the mind it is a universal. It does not really exist except either extramentally or in the mind, but this existence comes to if not from itself but from some other cause; and this is also true of the numerical plurality or universality that is the attribute of extramental or mental existence. Of itself or from itself the nature is neither one nor many, universal or particular: these attributes come to it not from itself, but from some other cause - the efficient cause that makes a horse actually exist outside the mind, or the intellect that forms a concept in which the nature of horse exists mentally.

Notice that on this theory the horseness that is just the nature of the horse and nothing else is not a product of mental abstraction but a reality independent both of actually existing horses and of human thought. In the prior instant of nature it is already there, waiting to be brought into extramental existence, or to be thought of. This is like a Platonic idea - it is Avicenna's equivalent.

But Avicenna is not saying that the horseness that is just horseness, "horseness itself" as Plato might say, is somehow real in separation from horses and thoughts of horses: it has no existence except either extramental existence in ordinary horses or conceptual existence in the mind, but it is the same nature that has both of these existences. "Although it is never really without some of these, still, of itself it is none of them; but it is naturally prior to them all".

So there are three headings: (1) the nature as it is of itself; (2) the nature as it exists outside the mind; (3) the nature as it exists in the mind. Write (1) beside "And according to this natural priority", (2) beside "Not only is a nature of itself indifferent", and (3) beside "And just as a nature is not of itself universal". In (2) the point to notice is that although as it exists in the intellect the nature is a universal, it does not have universality primo from itself. (Primo: "By virtue of being precisely that". An equilateral triangle has interior angles adding to 180 degrees, but this property belongs primo to it not precisely as equilateral triangle but to it as triangle. It is by reason of being a triangle that an equilateral triangle has angles added to 180 degrees.) If you form the concept of horse, your concept is a universal (since it can be predicated of many horses), but universality is not any part of the content of the concept of horse. According to medieval logicians universal is a "second intention", that is a concept applying not directly to things but to concepts.

For the last sentence of (2) read: "even though the intellect's mode of understanding is universality".

In (3), in the first sentence, "that existence" refers back to (2) - i.e. existence in the mind. Just as, when horseness exists in the mind, it is not of itself universal, though it is universal, so when it exists in external reality it is not of itself singular, though it is singular. When in this section by talks of "contracting", the image is of the contracting or narrowing down (for example) from substance to animate substance to animal to horse - until the final narrowing down to this horse. At each stage a contracting determinant (e.g. the specific difference) is added to narrow down the wider category or genus.

In the last sentence of the paragraph, beginning "And according to that being", "that unity" ("so that of itself it is not repugnant to that unity") refers not to the unity belonging to the nature of itself, which is indifferent to singularity, but rather to the unity of singularity, i.e. numerical unity.

In the next paragraph (beginning "In this way, therefore"), four lines down, "that unity" refers not to numerical unity but to "a real unity less than numerical unity" in the previous sentence.

The page you've just read, no doubt with some pain, is the main exposition of Scotus's doctrine of the "common nature". In this phrase "common" does not mean (as it often does in medieval texts) universal. It means the nature that can be either outside the mind or in the mind - the nature that is of itself indifferent to, and common to, these two different ways in which it can exist. Not only is the nature of horseness common to all horses, but it is "common" to them and to our concepts of horses. What comes to exist in our mind when we succeed in forming an adequate concept of a horse in the same nature that exists in horses.

Other theories of individuation

We will skip the rest of this question. Read, on p.586, just the last sentence of question 1. Questions 2 and 3 are not represented in these extracts. Question 2 is a rejection of the theory of Henry of Ghent, that the individual is individuated by two negatives: (1) a negation ruling out further subdivision into individuals of the same nature (a species divides into individuals of the same nature but an individual does not), and (2) a negation ruling out identification with any other individual. The first secures individuality (impossibility of division - whence the "-divid-" part of the word "individuality"), and the second secures distinctness: the individual is distinct from other individuals of the same nature. Scotus rejects Henry's theory. Question 3 is a rejection of another theory, that singulars are individuated by actual existence. This theory turns on a distinction drawn by many of Scotus's contemporaries, and by Scotus himself, between esse essentiae and esse existentiae, "being of essence" and "being of existence". In a prior instant of nature a thing has being of essence, then an efficient cause confers being of existence on it and it actually exists. Being of essence is what possible beings have. Impossibilities may be in some sense thinkable, but they have no real essence that can be defined. The theory criticised in question 3 is that Avicenna's horseness that is just horseness has being of essence, and when an efficient cause confers being of existence on it it becomes an individual horse - or, when the mind confers on it being in the intellect it is the universal.

This brings us to the next extract in Hyman & Walsh, p.586, question 4, in which Scotus presents and rejects a theory of individuation held by Thomas Aquinas and others, deriving from Avicenna. According to this theory material substances are individuated by their quantified matter. In fact this is more a theory of multiplication: what is it that multiplies individuals of a certain nature? How can one nature be in many individuals? The answer given by this theory is that matter multiplies: the nature is like a form received into many parts of matter. Imagine cutting out gingerbread persons with a cutter: they all have the same form, the shape of the cutter; they are many because they are different bits of dough. The many are of course distinct from one another; what makes them distinct is that the bits of dough are distinct. The distinction of the many individuals comes from the distinction of the parts of matter. According to Avicenna, Thomas Aquinas and others, matter has parts as quantified matter, with spatial dimensions. The gingerbread dough is spread out through distinct parts of space.

(You may find unquantified matter hard to imagine. In fact Aristotle's matter is something pretty unimaginable: it is potentiality, not of itself any particular kind of substance (it is what persists when one substance is changed into another), it does not of itself have any particular qualities - it is potential to receiving this or that quality; it is quantifiable but does not of itself have any particular quantity or location (it can be rarefied and condensed, located and relocated). Matter as merely potential does not exist by itself (according to Aristotle): it is always embodied in some substance with qualities, some quantity, etc.)

So in this theory it is not pure or mere matter that individuates, but matter as quantified. This is the theory Scotus criticised in question 4 - whether material substance is individual or singular through quantity? In q.5 (not in Hyman & Walsh) he disposes of other versions of the theory that somehow matter individuates. Thomas Aquinas's theory, and any theory that makes matter somehow the individuating principle, implies that immaterial natures are not multiplied - each immaterial substance, such as an angel, is a species by itself, without division into individuals: that is, each angel has its own nature, not shared by any other - as if among men Socrates and Plato were not two individuals somehow sharing one nature but two different natures. This implication of Thomas Aquinas's theory was controversial. The 219 propositions condemned by the Bishop of Paris in 1276 (see PHIL252 Readings, p.215, ppns. 42A, 43A), include: "That God cannot multiply individuals of the same species without matter" and "that God could not make several intelligences of the same species because intelligences do not have matter" - that is, not human intelligences but Separated Intelligences, Angels. The controversy over Thomas Aquinas's theory in fact provides the context of the questions we are reading. Book II, distinction III, is about angels. The questions about the individuation of material substances are preliminary to a question about the individuation of immaterial substances.

Read now on p.586 the first two paragraphs of q.4. Some comments. The term "primarily" (in line 2), in Latin primo, was explained above. Six lines down, "to be divided into parts of the same character" (Latin ratio): the parts of a species are its individual members, which all have the same ratio or definition. The parts of a genus are species, which do not all have the same definition. The parts of a body, e.g. of a human body, do not all have the same definition - an arm is not a leg. The parts of quantity all have the same ratio - one cubic centimetre has the same definition or concept as any other. So the theory is that the property of being divisible into parts of the same ratio belongs primo to quantity, and through quantity to the individual members of a species of material things.

Read the next paragraph, beginning "I argue against". Of the five headings in this list the extracts include only part of the first. Read the next paragraph, "As to the first way". In the middle of the paragraph note the phrase "subject-parts", or more literally subjective parts. This was the term used for the individual members of a species, perhaps because each of them can be referred to by the subject term (e.g. in the propositions "socrates is a human being", "Plato is a human being" and so forth). The point of this paragraph will be made clearer by the next. So read the next two paragraphs from the top of p.587.

Some comments, first on the text. In the third line of p.587, for "in one thing and another" substitute "be other and other". That is, this singularity cannot be replaced by another singularity. The argument is that the quantity and other accidents of a substance can be (at least by miracle) replaced by another quantity or other accident while the substance remains the same, but the singularity can't: so quantity (or other accidents) cannot be the source of singularity. Looking back to the previous paragraph we can now see the point: what individuates this thing is not just some singularity or other, but this one. Another alteration to the text: Near the end of the first paragraph on p.587, for "without substantial alteration" substitute: "the substance would not be altered by any substantial change. Whether this is possible or impossible" etc. To repeat: this argument is that any accident, such as quantity, can be replaced, at least by God's power, without the substance being changed; but its singularity, by which it is this substance (pointing to it) can't be replaced by another without the substance being changed; therefore demarkated singularity can't be due to quantity or any other accident.

The omission indicated by the omission dots includes the "second" corresponding to the "first" at the top of p.587, also the second and third ways referred to on p.586 in the second last paragraph. So these are (as that paragraph says) the three ways that prove that no accident can individuate. Now read the paragraph in the middle of p.587, "Perhaps to escape these criticisms".

This variant of the theory seems to be due to Giles of Rome, whom you met in PHIL252 as author of the pamphlet "The Errors of the Philosophers". The point of it is to draw a distinction between the demarkation of the substances and the demarkation of the quantity: the substances has its demarkation from the demarkated quantity, but, nevertheless, it is naturally prior to it. Five-six lines down in the paragraph underline "is naturally prior to the demarkation which it has through quantity". So here X is prior to Y, and yet X is had through Y. And this demarkation of substance is identical with the substance. Not a very promising theory.

Now read the next three paragraphs.

Scotus's theory of the "individuating entity"

Let's turn now to the translation I have distributed. This is not a series of extracts, but a complete translation of a whole section of Scotus's Ordinatio (or Opus Oxoniense); I won't expect you to read the whole. First leaf through it and notice the headings in capitals (not in the Latin text). On the first page, paragraphs 130 and 131, we have the argumenta principalia - meaning not "principal" arguments but "beginning" arguments. These are equivalent to the preliminary arguments pro and con, or "objections", of a 13th century disputed question (or of a question of Thomas Aquinas's Summa theologiae). Then comes a section on the opinion of others, which became a common feature of "questions" in the 14th century. First the opinion is stated, paragraphs 132-135, then objections are made to it, paragraphs 136-141. Next at paragraph 142 Scotus raises another question, question 6, to be answered before question 5. First come the argumenta principalia (paragraphs 143-147); then the section on the opinion of others - stated in paragraphs 148-154, argued against in paragraphs 155-167. Then at paragraph 168 comes Scotus's own solution to question 6, corresponding to the "I answer that" section of a question by Thomas Aquinas. None of the arguments up to this point can with complete safety be attributed to Scotus himself. This section, the author's solution, often contains objections and answers, for example at paragraphs 171 and 172-175. Then, at paragraph 189 comes the answer to the argumenta principalia for question 6, and then, at 194, answers to the arguments for the opinion of others. Having disposed of question 6, he then at paragraph 200 returns to question 5, out of which q.6 arose, and gives a brief solution, and then (at paragraph 201) answers, but not in the same order, the argumenta principalia of q.5 and the arguments for the opinion of others, i.e., the texts of Aristotle in paragraph 132ff. This is a typical 14th century "question", typical in having a major section devoted to other opinions, and in the flexibility of organisation that allows two questions to be treated together.

I'm not asking you to read all of this. It will be enough to read the solution to question 6, omitting paragraphs 171-5 and 182.

So now read paragraphs 169 and 170. His theory is that each individual is individuated by an individuating entity which is one of the parts of that individual, forming a genuine unity with its other parts (and they make "something one per se" as he says at the end of paragraph 169). In comparison with one another, the several individuating entities of several individuals are primo diversa, utterly other than one another by virtue of being what they are. From every entity results some unity (remember the doctrine of transcendentals, according to which every being is one), and the unity resulting from the individuating entity is singularity - not just singularity in general, but "demarcated" - i.e. so that the individual is this (pointing to it).

Let's skip the objection and answer (paragraphs 171-175). Now read paras 176-178. He is talking about ultimate species, below which the only further division is into individuals having the same nature and definition, not into narrower species (which would differ from one another in nature and definition). At the beginning of paragraph 177 he says that it is repugnant with the ultimate specific difference for any further division into species or natures to occur, and it is through that specific difference that this exclusion of further such division belongs to the whole specific nature. Take the nature of the human species, assuming that this is an ultimate species. Its definition (let's assume) is "rational animal". Its indivisibility into further species is obviously not due to the "animal" part of the definition of human nature, since animal does admit division into various species, the various species of animals. The indivisibility into species of human nature must be due to the other part of the quiddity, the rationality, the specific difference. Similarly, in the case of individuation, it must be through the individuating entity that there is repugnance to further division into individuals. Scotus is drawing an analogy between specific difference in relation to genus and individuating difference in relation to specific nature, between the impossibility of dividing an ultimate species into further species and the impossibility of dividing an individual into further individuals. (An individual human being can be divided into quantitative parts - e.g. a leg can be amputated, but not into "subjective" parts, i.e., parts of the same ratio or nature).

Now read paragraphs 179, 181. There is at least a formal distinction between genus and specific difference; the genus is potential or determinable, the specific difference is actual or determining (or in linguistic terms one is noun and the other adjective). Similarly there is a formal distinction between the specific nature and the individuating difference, and the latter is actual and the former potential or determinable.

Note in paragraph 180 that the individuating difference is not really distinct but is formally distinct from the specific nature, like "infinite" in relation to being. (See Hyman & Walsh, last paragraph of p.563). Just as "intense white" expresses an intrinsic degree of whiteness, so the individuating entity of this human being is "the ultimate reality" of the human essence. Note also that, unlike the specific difference, the individuating entity is not part of the quiddity of the individual - otherwise each individual would have a different definition. The "individuating entity" is looking rather like the "existence" that Scotus argued in question 3 cannot be the individuating principle. I think Scotus would say (using the device of "instants of nature") that "thisness" is the last actuality just before existence. It seems to come between quidditative being and the being of existence. In Scotus's theory actuality has layers like an onion. The last or outermost actuality is existence; the second last is thisness; under that there is the specific difference, which is actual in relation to the genus, which is quasi-potential; and the specific and generic natures may themselves include a distinction between act and potency - material substances include matter, which is potency, and form, which actualises the potency of matter.

Now read paragraphs 187-188.

Go back and read to paragraph 183. Notice that the three comparisons, which I have marked as (a), (b) and (c), are of specific difference with something else - with individuating entity, with genus, with another specific difference; but the point of these comparisons is to clarify the individuating entity. Scotus has modelled the individuating entity on the specific difference: as the specific differences divide a genus into species, so the individuating entities divide a species into individuals. But there are differences, chiefly (1) that the individuating entity does not enter into the quiddity of individuals - their definition is the definition of their species; and (2) that the distinction between individuating difference and specific nature is a formal distinction, whereas there is a real distinction between specific difference and genus.

Now read paragraphs 184-186, cf. footnotes 4 and 11.

I will now leave Scotus's account of individuation. See "Scotus's Individuation Theory" by A.B. Wolter, from his book The Philosophical Theology of John Duns Scotus (Cornell University Press, 1990). This is the end of tape 6.

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