"I do hold this, that no universal, unless perhaps it is universal by a voluntary agreement, is something existing outside the soul in any way, but all that which is of its nature universally predicable of many is in the mind either subjectively or objectively, and that no universal is of the essence or quiddity of any given substance."

This ringing declaration closes William of Ockham's lengthy discussion of universals in Ordinatio I d.2 qq.4-8 (pp.291-292). In qq.4-7 he criticizes positions holding that the universal is somehow a real existent outside the soul, presenting his view that universals are nothing but words as the conclusion to be drawn from the failure of these realist positions to stand up to his rigorous examination. Ockham's positive account should therefore avoid the realist commitments of his predecessors while managing to satisfy the demands of rigor and subtlety established in his critique.

That isn't what happens. Instead, Ordinatio I d.2 q.8 is indecisive: several identifications of universals are presented but none clearly endorsed. The text itself is heavily revised in a later redaction and a new alternative appended to the discussion. Ockham is sure that no form of realism about universals is acceptable, but doesn't seem to know what to put in its place.

I want to explore the insights that nourished Ockham's positive views about nominalism and also threw him into such uncertainty. The results are be instructive, since Ockham was struggling with difficulties that continue to plague philosophers who want to avoid a pure conventionalism and yet find realism about universals an unacceptable alternative. Ultimately, I believe, his attempt fails, though not for any lack of ingenuity, and his failure is itself instructive about the possible forms and limits of nominalism.

Universals, Ockham declares, "are not things other than names" -- names predicable of many, that is. But are all such names universal? If universals are linguistic tokens, do they come into being and pass away? Do distinct languages have different universals? To avoid difficulties stemming from the conventionality of language, Ockham has recourse to a device inspired by Aristotle, namely to hold that there are three hierarchically-ordered levels of language, written language, spoken language, and mental language, where the first two are conventional but the last not.<2> Each is complete, with its own vocabulary, rules of syntax, and semantics. For Ockham, the constituent elements of written language are linked piecemeal to the constituent elements of spoken language, and those of spoken language piecemeal to mental language (Summa logicae I.i-ii). These semantic linkages Ockham calls 'subordination': written language encodes spoken language, which in its turn encodes mental language. The constituent elements of mental language, however, are not an encoding; they are directly related to extralinguistic items, a relation Ockham calls 'signification' -- the mediaeval correlate to the modern notion of 'meaning'.<3> Terms of spoken language are said to 'signify' whatever the mental term to which they are directly subordinated signifies, and terms of written language 'signify' whatever the mental term to which they are indirectly subordinated, via spoken language, signifies.

Thus mental language functions as the semantics of written and spoken language.

Ockham therefore identifies universals with concepts that can be the terms of mental language.<4> He rejects the suggestion that terms of written or spoken language, independently of their connection with mental language, can be called universals.<5> Hence Ockham is sometimes called a conceptualist rather than a nominalist, although given the close connection between spoken/written language and mental language both names are apt.

Universals, then, are concepts that can be the terms of mental language.<6> More accurately, universals are concepts which are predicable of many, and therefore must be apt to signify many. Hence the signification of a mental term determines whether that term is a universal. In keeping with the denial of conventionality for mental language, Ockham holds that concepts are non-conventional signs of what they signify -- in his terminology, a concept naturally signifies its significates.<7>

To explicate the natural signification of universal terms, Ockham uses a common analogy: concepts 'picture' that of which they are concepts -- as Aristotle suggests, concepts are "representations or likenesses, or images, or copies" of their significates.

Ockham puts forward two proposals for a theoretical reconstruction of picturing. The first is that the concept the mind fashions to itself is objectively similar to extralinguistic entities, or possesses features that are objectively similar to extralinguistic entities or their characteristics; picturing would then be explicated in part by the notion of resemblance. The second is that an extralinguistic entity plays an objective causal role in the mind's fashioning of a concept to itself; picturing would then be explicated in part by this causal role, or, more exactly, by the converse of the causal relation. In short, Ockham relies on intrinsic and genetic features in his account of natural signification as a kind of picturing.

While it seems unproblematic that the causal relation or its converse is in fact objective, i.e. that it obtains regardless of any (non-divine) mental activity, it is less clear that resemblance or similarity is objective rather than being in the eye of the beholder. However, Ockham explicitly describes similarity as a "real relation" -- a relation for which no intellectual activity is required, which must be present given the nature of the relata.<8> Two items are similar (or dissimilar) by their nature, regardless of anyone's thinking so. Hence if picturing is a matter of resemblance it must be a real relation, and the signification of a term will thereby be independent of cognitive states.

Is the interpretation of picturing as resemblance, even as a real relation of resemblance, compatible with Ockham's nominalism? If Socrates is white and Plato is white, then the correct description of this situation seems to be that Socrates resembles Plato in respect of whiteness. The locutions 'x resembles y' or 'x is similar to y' are sometimes held to be incomplete contexts, properly filled out as e.g. 'x resembles y with regard to F-ness.' Resemblance is then taken to be a triadic relation which essentially involves an abstract entity, the respect in which two items can be said to resemble each other.<9> To avoid such a hypostasization, Ockham rejects this line of reasoning, concluding instead that resemblance is a dyadic relation and that at least some claims of the form 'x resembles y' are complete, having the sense of 'x is globally similar to y'.<10> Global similarity is a matter of the characteristics of each of the relata, and immediately obtains given the relata.<11> But Ockham's recourse to this move just points up the difficulty: how are such claims of global similarity judged true or false? If everything that exists is individual, and individuals are completely discrete entities with nothing in common, it isn't clear how Ockham can maintain that Socrates and Plato are globally similar in a way in which Socrates and an ass are not. The difficulty is even more acute by Ockham's insistence that there must be grades or degrees of global similarity. For Socrates and an ass are globally similar, since they are both animals, but they are somehow 'less' globally similar than Socrates and Plato. Without an account of the truth-conditions of resemblance-claims, the attempt to explicate natural signification in terms of resemblance seems bound to fail.

Ockham recognizes that similarity, even global similarity, can't be the whole story. In Ordinatio I d.2 q.8 he cites Augustine, who emphasizes the lack of similarity between a picture and what it depicts -- indeed, Augustine emphasizes the arbitrariness of the picture. For example, Augustine describes imagining the city of Alexandria, which he had never seen, and notes that it would be miraculous if it were anything like Alexandria; equally, when reading the Bible, one fashions mental images of the Apostles and of Christ that are probably unlike their actual appearance. Ockham concludes that similarity can't altogether explain intentionality.<12>

A moment's reflection on pictures illustrates why his conclusion is correct. A picture by itself will not determine whether it depicts Socrates or his twin brother.

Indeed, a picture may resemble another person more than the one who sat for it. Any picture of a man will clearly resemble some men more than others. A composite drawing, in which the eyes are drawn from one model, the nose from another, and so on, will not exactly resemble any of these models, and if it should happen to exactly resemble some other person, that seems to be purely accidental or fortuitous.

Such cases might lead one to the conclusion that pictures are inherently general, and that the difficulties inherent in picturing an individual are the root of the problem. But such a conclusion, while tempting, would be hasty, since the same difficulties could be raised with pictures meant to depict not a single individual but of a class of individuals. Does a picture of Socrates globally resemble Socrates, human beings, animals, living beings, material substances, any or all beings? Two-legged animals? Famous philosophers? Ugly bald men? An argument could be made for each. Nor does it help to move to comparative resemblance-claims, since it isn't clear whether a photograph of Socrates is 'more' globally similar to all animals rather than the two-legged animals, or to all beings rather than all animate beings. Pictures of themselves don't make such distinctions, whether resemblance, global resemblance, or comparative global resemblance is the issue.

The intrinsic features of pictures are no guide to what they picture.

However, pictures also have genetic features, and in particular bear a special relation to their source -- the extralinguistic entity that plays or can play a causal role in the production of the picture.<13> The failure of resemblance drives Ockham to consider such intrinsic features. And they are instrinsic: the kind of cause it takes to produce an effect is part of the nature of that effect.<14> Thus it is part of the nature of being human that humans are produced by two partial co-causes, the mother and father, while it is the nature of, say, a footprint, that it is produced by the kind of foot in question. Furthermore, any particular effect must be produced by a particular cause, so that a particular child is produced by a definite pair of human parents and no other, and this footprint by that foot and no other.<15> Thus while a particular concept, e.g. the concept of Socrates, may resemble Plato more than anyone else, if it is originally acquired from causal interaction with Socrates himself then it will be a concept of Socrates. Normally a picture will globally resemble that of which it is a picture, that is, its intrinsic features which determine resemblance will be tightly linked to the actual features which the object figuring in its formation possesses, and so there need be no reason for sharply distinguishing intrinsic and genetic features of the picture.<16>

This strategy seems designed to cope with concepts of individuals, or, in its linguistic version, to account for the referential function of proper names. Can it be generalized to apply to common names, that is, to concepts of kinds of individuals? In Quodlibeta I q.13 Ockham states that "the concept of a genus is never abstracted from one individual"; rather, general concepts are fashioned from several cases by comparison.<17> But this seems to block the move to considering the genetic features of a general concept, since comparison by its nature is a matter of similarity or resemblance. One suggestion, with some foundation in Ockham's text, would be to alter the story slightly by supposing that the memory of distinct individuals of the same kind can act as partial co-causes to automatically produce a general concept as an effect; this would allow a unified causal account of its genetic features.<18> The individuals would then be reasonably close partial co-causes of the general concept, much as it is part of the nature of a human being to be produced by four grandparents (with some intermediate steps).

The general concept thereby produced, however, will be genetically linked to the particular individuals that played a causal role in its production and not cover individuals of the same kind that didn't play such a role. Rather, what is required is for the general concept to be genetically linked with all individuals apt to cause such an effect of their very nature. But that is a very small circle, since there isn't a way to specify the 'effect' without the class of individuals that would produce it -- the very difficulty in the case at hand. More exactly, an individual will have the causal power to produce a given concept in combination with other individuals of the same kind: but the causal power is defined by reference to the 'given' concept and to 'individuals of the same kind,' which is circular.

There is a more general difficulty. Take two individuals, say Socrates and a tomcat. Even if they concur to produce a general concept, why should they produce the concept of animal rather than the concept of male? There is no reason why the general concepts that are produced should match the standard Aristotelian division into natural kinds.<19> This difficulty is the result of Ockham's failure to distinguish criteria specifying what it is for a term to be general, which a term like 'male' would satisfy, from more stringent criteria singling out the privileged class of 'natural-kind terms'.<20> Without such a distinction it seems impossible to guarantee the possession of one set of concepts rather than another -- the very reason Ockham has recourse to mental language in the first place.

Ockham explicitly holds that the intellect and the external object function as partial co-causes of the cognition of the object. It might be possible to maintain that the intellect is so structured as to classify all perceived objects into a set of privileged concepts, those corresponding to natural-kind terms. These concepts would then be innate, triggered through causal interaction with the right sort of object. Hence the intellect would be pre-disposed, presumably by God, to ideate in determinate ways in the presence of different kinds of objects. This suggestion, however, assumes that the appropriate genetic connection obtains between individuals and concepts, and so cannot explain such a connection.

No matter which route is taken, emphasizing the intrinsic or the genetic features of pictures, there are difficulties for a nominalist semantics. The problems each has may be symptomatic of a deeper problem, namely that 'picturing' cannot of itself provide an explanation of signification because picturing is as much an intentional activity as signifying: pictures are of themselves inert, and only succeed in picturing when treated as signs. Yet this is precisely the aspect of signifying which the move to mental language and picturing was supposed to explain. A picture in which Socrates is depicted might equally be a portrait of Socrates, and so to depict Socrates, or it might stand for humans, or animals, or substances, or beings. The picture in itself gives no clue which interpretation is the intended one, and so no account of a picture solely in terms of resemblance can be satisfactory. Equally, the genetic features of the picture give no clue, because again it is unclear whether Socrates should be construed as the cause of the picture as an individual, or as a human, or an animal, and so on. In either case, there must be an act of stipulation which specifies how the picture is to be taken.

But to require such a stipulative act is just to require further intentional activity to explain picturing. What is more, such further stipulation certainly makes mental language far less 'objective' than Ockham initially supposed; there could be distinct stipulations in distinct communities, or between distinct individuals: the move to mental language cannot succeed in avoiding the conventionalism it was introduced to avoid.

There are special difficulties in combining the intrinsic and genetic accounts of picturing. Given that a picture need not resemble that which causally figured in its production, which feature determines what the picture is a picture of?

Ockham doesn't give any determinate answer to this question.

One possible answer is that which feature predominates in determining the signification of a term is a function of the term's use. Thus when a term appears in a sentence, that is, when it is used referentially, the genetic features predominate, while in a freestanding occurrence the intrinsic features predominate. Thus in a sentence, a term may "stand for what it signifies," i.e. have an ordinary referential use, while considered in isolation a term may simply "bring something to mind," i.e. resemble distinct individuals. Of course, then there will be no simple answer to the question what a term signifies, since it may signify disjoint classes of individuals depending upon its use.

If, as I have argued, Ockham cannot develop a coherent theory of the underlying semantic mechanism of signification, then his attempt to produce a rigorous and consistent nominalism has failed. But the failure of his attempt is instructive, for it points up a difficulty any version of nominalism, mediaeval or modern, must face: an explanation of semantic generality that does not rely on any real metaphysical generality. Perhaps his deepest error is to treat terms as having semantic properties which are not themselves derivative from their use in sentential contexts -- an error based in his conviction that concepts are somehow in themselves intrinsically meaningful and can function as an independent language. The conviction that there are real natural classes and that we are somehow structured in such a way as to grasp these classes, without any metaphysical basis for the assortment into classes or for our general terms to pick them out, seems no more than an empty refusal to take into account the evident difficulties such a conviction entails. The failure of Ockham's nominalism points the way towards a more robust nominalism, one that can learn from and avoid Ockham's mistakes.


NOTES<1> References are to the critical edition of Ockham's non-political writings, Guillielmi de Ockham opera philosophica et theologica, eds. Gedeon Gál, Stephen Brown, et al., The Franciscan Institute, St. Bonaventure, New York: 1967-1985. Ockham discusses universals at length in two places: Ordinatio I d.2 qq.4-8 (Opera theologica tom.II), and Summa logicae I.xv-xvii (Opera philosophica tom.I). He discusses them summarily in the preface to his Exposition of Porphyry's "Isagoge" (Opera philosophica tom.II) and in Quodlibeta V qq.12-13 (Opera theologica tom.IX).

Translations are mine.

<2> See Aristotle, De interpretatione 1 16a1-14:

"Spoken words are symbols or signs or affections of the soul; written words are the signs of spoken words. As writing, so also speech is not the same for all men. But the mental affections themselves, which these words are signs of, are the same for all mankind, as are also the objects for which those affections are representations or likenesses, or images, or copies... A name or a verb by itself much resembles a concept or a thought which is neither conjoined nor disjoined."

This passage was understood as translated by Boethius with his associated commentary; see Norman Kretzmann, "Aristotle on Spoken Sound Significant by Convention," in John Corcoran, ed. Ancient Logic and Its Modern Interpretations, D.Reidel: Dordrecht 1975, pp.3-21. Ockham mentions Aristotle and Boethius while discussing the passage in Summa logicae I.i (p.7).

<3> Technically, a word has signification regardless of context, even in a freestanding occurrence. Words, or at least names, refer or 'supposit' only when they appear in sentential contexts. Our concern here is with cases of ordinary referential uses (or 'personal supposition'), in which a term "stands for what it signifies" (Summa logicae I.lxiv), i.e. refers to either all or some of its significates depending on the sentential context of its appearance.

<4> Which concepts can be the terms of mental language, and which of these correspond to universals? Ockham argues that mental language contains no synonyms; that it contains only absolute terms; and that categorematic terms, not syncategorematic terms, are (candidates for) universals.

Given these restrictions, it is by no means evident what the class of non-complex absolute categorematic terms which are predicable of many includes. I propose to set this question aside, assuming that concepts corresponding to natural-kind terms such as 'man' and 'animal' are universals.

<5> Ordinatio I d.2 q.8 (p.271):

"Fourth, there could be a position that nothing is universal of its nature but only by convention (institutio), in the way in which a word is universal, since no thing of its nature has to supposit for another thing, nor be truly predicated of another thing, just as no word does [of its nature] but only through a voluntary convention; and so, just as words are universals, and predicable of things, by convention, so too all universals. But this [position] does not seem true, since then nothing would be a genus or species of its nature, nor conversely, and then God and substance outside the soul could equally be as universal as anything in the soul, which doesn't seem true."

The latter part of the objection is obscure, but I take it the complaint that 'nothing would be a genus or species of its nature' is meant to reject a purely conventional nominalism.

<6> Ockham discusses these various theories in Ordinatio I d.2 q.8 (in each redaction), the preface to his Exposition of Aristotle's "De interpretatione", the first seven questions of his Questions on Aristotle's "Physics", and Quodlibeta IV q.35. Modern commentary has focussed on Ockham's uncertainty over the nature of concepts: he describes, and at different times seems to endorse, at least three distinct theories: (a) the concept is something 'objectively existent' in the mental act, that is, something fashioned by the mind and is the object of the mental act, called a 'fiction' (fictum) and closely related to the modern notion of an intentional object; (b) the concept is to be identified as a quality of the mind, distinct from the mental act; (c) the concept is simply the mental act itself.

The most plausible interpretation is a developmental hypothesis: Ockham began by endorsing (a), but difficulties about the ontological status of such fictions forced him to abandon this position in favor of holding that concepts must have real existence or 'subjective being' in the soul, as (b) and (c) maintain, and considerations of parsimony eventually pushed Ockham to (c) -- his mature view. (The story is more complex, involving a debate between Walter Chatton and Ockham -- see Philotheus Boehner, "The Realistic Conceptualism of William of Ockham," Traditio vol. IV (1946) pp.307-335; Francesco Corvino, "Sette questioni inedite di Occam sul concetto," Rivista critica di storia del filosofia vol. X (1955), pp.265-288; Gedeon Gál, "Gualteri de Chatton et Guillelmi de Ockham controversia de natura conceptus universalis," Franciscan Studies vol. XXVII (1967), pp.191-212; Marilyn M. Adams, "Ockham's Nominalism and Unreal Entities," Philosophical Review vol.LXXXVI (1977), pp.144-176 and her William Ockham Ch. 4, University of Notre Dame Press 1987 -- but we can ignore this complication.) This strikes me as correct but only tangentially related to Ockham's account of universals. Whether we allow that there are objectively existent fictions or not, any successful account of concepts has to accommodate something equivalent to such fictions, that is, has to allow that the mind can fashion ideas of objects, some of which, like the chimaera, may not be capable of existence. Thus there must be an equivalent translation of any such claim in terminology respecting the ontological foundations of each of (a)-(c).

Ockham himself gives an example of such a translation, from (a) to (c), in the preface to his Exposition of Aristotle's "De interpretatione" I §9 (pp.366-367). Ockham's claims about fictions are thus independent of the particular foundations adopted, and so I'll use this terminology freely, without any particular ontological commitments.

<7> Summa logicae I.i (p.7):

"A term which is a concept is an intention or affection of the soul naturally signifying or consignifying something, apt to be part of a mental sentence and to refer (supponere) to its significate."

See also Marilyn Adams, William Ockham Ch.3 (pp.121-133), University of Notre Dame Press 1987, to whose discussion I am indebted.

<8> Ordinatio I d.30 q.5 (pp.385-386):

"For similarity is called a 'real relation' in that one white [thing] is similar to another white [thing] by its nature, and the intellect no more makes it be the case that one is similar to the other, any more than it makes it to be the case that Socrates is white or that Plato is white... When a thing is such as it is indicated to be by a relation or a concrete relative [term] without any activity of the intellect, such that intellectual activity does not make it to be [so related], then it can be called a 'real relation' in the manner described before."

<9> This claim is often advanced on two independent grounds. First, it is sometimes taken to be a corollary of the metaphysical claim that any two entities will resemble each other in an infinite, or indefinitely large, number of ways. While this does not, strictly speaking, entail the claim that resemblance is triadic, but only that any resemblance-claim is trivially true, that conclusion vitiates much of the point of making any resemblance-claim.

Second, it is sometimes held that the meaning of 'resemblance' is incomplete or necessarily triadic.

<10> Ordinatio I d.2 q.6 p.211-212:

"If it were objected that Socrates and Plato really agree more than Socrates and an ass, and so Socrates and Plato agree in something real in which Socrates and an ass do not really agree, but not in Socrates nor in Plato; therefore, they agree in something distinct in some other way which is common to each -- I reply that literally it should not be granted that Socrates and Plato agree in something or in some things, but that they agree with some things, since they agree of themselves, and [it should be granted] that Socrates agrees with Plato not 'in something' but 'with something', since they agree of themselves."

See also Summa logicae I.xvii p.58 for this account.

<11> There is an obvious difficulty: how can concepts, which are (at least) mental qualities, be said to 'globally resemble' extramental individual substances? Indeed, how can immaterial accidents 'resemble' material substances? Ockham raises this objection in Ordinatio I d.2 q.8 (p.282) only to dismiss it, saying that such fictions "are in objective being as others are in subjective being; and the intellect, from its nature, has the ability to fashion such [fictions] of what it knows to be external" (p.284).

<12> Ordinatio I d.2 q.8 p.278:

"It is clear that, although due to the diversity in shape and color and other accidents in diverse men we can fashion diverse [fictions] which are not similar to every man (or perhaps [are similar to] no man), nevertheless, we can have a notion of some fiction which is equally related to all men, according to which we are able to judge of anything whether it is a man or not."

<13> Ordinatio I d.2 q.8 p.277:

"All things consimilar to what was previously seen are, as it were, suggested and signified by a fiction [fashioned] from something seen. This is nothing else than to affirm or deny something of such a fiction, not for itself but for the thing from which it is fashioned or can be fashioned."

Strictly speaking, it is only a partial cause, along with that which does the picturing -- the camera, the mind, the artist -- but for our purposes we may ignore this complication.

<14> The same conclusion is drawn more explicitly in Reportatio II qq.12-13 (pp.287-289):

"I say, then, that the act of understanding (intellectio) is the similitude of the object, just as if the species were posited, and it is no more the similitude of one than of another. And hence the similitude is not the precise cause whence one understands one and not the otherŠ although the intellect is assimilated to all individuals equally, nevertheless it can determinately know one and not the other. Yet this is not according to assimilation, but the reason is because every naturally producible effect from its nature determines to itself that it is produced by one efficient cause and not another, just as it determines to itself that it is produced in one matter and not another...

although the [concept] would be equally assimilated to many individuals, nevertheless from its nature it determines to itself that it leads the intellect into the cognition of that object by which it is partially caused, since it determines to itself to be caused by that object such that it cannot be caused by some other [object]. And so it leads into the cognition of it such that it does not lead into the cognition of another."

In Quodlibeta I q.13 Ockham takes up the objection that an intuitive cognition resembles two extremely similar objects equally well; he responds (p.76):

"The intuitive [cognition] is the cognition proper to the singular, yet not according to the greater assimilation of one than of the other, but because it is naturally caused by the one and not the other, nor can it be caused by the other."

<15> This doesn't rule out divine intervention, nor does Ockham intend that it should.

<16> Ockham describes intrinsic and genetic features involved in picturing in Ordinatio I d.3 q.9 (p.547):

"A 'trace' (vestigium) and an 'image' (imago) differ in this regard, namely that it is part of the definition of a trace that it is caused by that of which it is the trace. This is clear by example, since as trace is said to be left behind "by another". However, it isn't part of the definition of an image that it is caused by that of which it is an image; the image of Hercules, for example, may be sufficiently caused by someone other than Hercules."

Both traces and images (in Ockham's technical sense) are general, and may resemble distinct things equally well (p.546). A picture may function as both a trace and an image; a photograph is equally an image of Socrates and of his twin brother, but only one of the two will figure in its genetic features as its cause.

<17> This needs to be qualified. The story Ockham proposes in Ordinatio prologue q.1, Reportatio II qq.12-13, and Summa logicae III-2.xxix is more complex, and proceeds roughly as follows: beginning with an intuitive cognition in the sensitive soul of an individual material substance or quality, this cognition together with the object 'naturally causes' an intellectual intuitive cognition of the same object; such acts of intuitive cognition are accompanied by acts of abstractive cognition, and the latter either remain in memory directly or through a 'recordative' act. Once at least two abstractive cognitions of the same kind of thing are present in memory (Ockham seems to ignore the case of multiple cognitions of the same thing), the intellect compares them and constructs an abstractive general concept based on their global similarities and differences.

<18> In Reportatio II qq.12-13 Ockham endorses the general claim that "given a sufficient agent and patient in proximity, the effect can be posited without anything else." Applied to ordinary cases of cognition, the 'agent' is identified as both the external object and the intellective disposition, as material and immaterial partial co-causes, and the 'patient' is the intellect; the effect is the occurrent act of understanding. For the formation of the intellective disposition, the 'agent' is the external object and the 'patient' the sensitive and intellective souls.

Hence Ockham simply declares it to be the nature of the sensitive and intellective souls that an object is both sensed and understood when it is present or "in proximity," with no need to postulate intermediary mental activity; sensing and understanding are distinct effects of the same cause, the former proximate and the latter remote.

<19> Even if we accept the Aristotelian notion that general terms fall into a rigidly structured hierarchical pattern, the division of living beings into male and female, and then each of these into correlated sub-kinds such as human and feline, fits the pattern as well as the division of living beings into human and feline, and then each of these into correlated sub-kinds such as male and female.

<20> Ockham does recognize the distinction between 'merely' general terms and natural-kind terms; he takes the former as the class of 'connotative' terms and the latter as 'absolute' terms (Summa logicae I.x). However, the difference between the two classes of terms is explained their signification, through the doctrine of real and nominal definition, and so cannot be used to explain signification itself.