Let me begin my comments on Peter King’s paper by declaring that I thoroughly agree with its main claims, namely, that Ockham’s nominalism fails in some important respect, and that we can learn a great deal from understanding exactly what this failure consists in. I am not entirely convinced, however, that the paper manages to provide us with the desired precise characterization of the nature of Ockham’s failure.

In order to understand the nature of Ockham’s failure, first we should clearly see the problem that Ockham fails to solve. Based on the initial considerations of the paper, I take it that the problem can be characterized by the following question. What is it that accounts for the relation of natural signification between simple universal concepts of the mind and particular entities of extramental reality, excluding the existence of extramental universal entities?

The paper considers and rejects two solutions proposed by Ockham: similarity and causality.

The paper’s first objection to the proposed solution in terms of similarity has to do with the fact that when we judge things to be similar, we compare them with respect to some of their characteristics. Hence, the similarity relation between two particulars seems to have a third argument-place, reserved for some common characteristic in respect of which two particulars are deemed similar or dissimilar. But then, since this third argument-place apparently needs to be filled in with some "abstract entity", a universal, similarity so interpreted cannot provide an acceptable solution for a nominalist.

This argument may seem effective, but it may not be based on a correct interpretation of Ockham’s concerns in the passage quoted in the relevant footnote (10). For Ockham’s main concern there seems to be simply to establish that we need not posit some human nature distinct from individual humans to account for their specific unity, but he does not appear to be addressing the general issue of how many terms similarity requires. But regardless of the interpretational problem of identifying Ockham’s true meaning there, it is simply not true that a three-place analysis of similarity entails commitment to "abstract entities", that is, to universals. For example, if Plato and Socrates are similar in respect of whiteness, then Plato has to have his own whiteness and Socrates has to have his own whiteness, yet there need not be a universal thing called ‘whiteness’, which somehow should belong to both of them.

Indeed, the case of similarity in respect of whiteness would be a special case for Ockham, as he admits a real distinction between a particular whiteness and its subject. However, in the case of similarity with respect to shape, for example, he would not be committed to anything besides the particular things thus and so shaped, since he would not regard their shapes as distinct from the things themselves. For example, two billiard balls on this account may be similar with respect to their shape, while dissimilar with respect to their color. Yet, this does not require either the existence of a separate shape-thing which is one in itself and distinct from each of these balls, or the existence of two shape-things, which are inherent in, but still distinct from, their respective subjects. Each of the balls is round in virtue of its own shape, but this shape is nothing but the ball extended in such a manner that all points of its surface are equidistant from a given point. So the balls are similar with respect to shape, each being its own shape. In the same way, two humans may be said to be similar with respect to humanity, each being their own humanity, and two animals may be similar with respect to animality, each being its own animality, etc. Indeed, it does not matter here whether we take ‘similarity’ to be a generic term covering more specific F-wise similarities in the way Marilyn Adams suggested, or we take it to be a determinable to be determined by the qualification ‘with respect to F-ness’, as long as we provide the same type of analysis in both cases.

The next move of the paper is to claim that in view of the unacceptability of the three-place analysis of similarity, Ockham will rather use a notion of "global" similarity. However, if the three-place analysis of similarity does not necessarily involve commitment to universal entities, Ockham need not be committed to "global" similarity, to be interpreted as similarity without any qualification or specification. But then, the problems arising from the unintelligibility of different scopes and degrees of "global" or unqualified similarity need not threaten his account. What these arguments show is rather the fact that similarity always has to be judged in some respect, and that, accordingly, if concepts are to be similar to the objects they represent, and they represent them on account of this similarity, then they should represent them in some respect. (This is an important point to which I will return later.) But since admitting similarity in some respect need not involve commitment to extramental universals, these arguments in themselves need not pose a threat to Ockham’s account in terms of similarity.

Perhaps, a more promising line of attack concerning the similarity-account would be to ask how Ockham could interpret similarity between concepts and extramental material substances at all—a question Ockham himself raised against his own fictum-theory. For at this point realists can still offer us a story which is simply unavailable to Ockham’ mature theory. Being the staunch nominalist he is, Ockham simply cannot afford the luxury of talking about different instances of the same nature. But realists can claim without further ado that the reason why concepts are similar in some respect to the objects they represent is that the concepts of individual human minds are just further instances of the same nature that informs these objects. To be sure, as far as moderate realists are concerned, the nature informing the mind and the distinct particulars can only be formally, but not numerically the same nature. Also, since the mind informed by this nature does not become one of the particulars having this nature, the nature has to have a different mode of being in the mind than in the particulars. As a consequence, the realist account will have its own problems in explaining what it means for numerically distinct entities to be formally the same, and what it means for the same nature that informs the particulars to have a different mode of being in the mind. Sill, the realist account is at least clearly able to give an answer to the general question of what makes a particular act of a certain human mind related to a whole set of individuals. Indeed, it can do so despite the fact that a human mind typically cannot get into a causal contact with all those individuals. But this observation already takes us to the second alternative considered by the paper.

As the paper correctly argues, Ockham’s causal account should obviously work in the case of individual concepts. If an object is the cause of a concept, then there clearly is a natural relationship between the object and the concept, which can be utilized in explaining why the concept is a natural representation of the object in question. Certainly much more would need to be said about exactly how the causal mechanisms involved give rise to a relation of natural representation. But at least the general question of what fixes the relation of natural signification may plausibly be answered in this way.

However, when it comes to accounting for universal concepts, even this general question does not seem to be answered. For a universal concept has to represent several particulars, indeed, sometimes an infinity of particulars, with which the mind having the concept has never been in any causal relationship.

Naturally, one would wish to say here that the causal relationship with a restricted number of particulars establishes a relationship of natural signification not only between these particulars and the concept they give rise to, but also between the concept and all particulars of the same kind that have an equal ability to produce the same concept. But, as the paper points out, there is a danger of circularity here in referring to particulars of the same kind having an equal ability to produce the same concept. For then the question is whether Ockham is able to specify the class of all particulars belonging to the same kind without invoking the concept produced by a restricted number of them. If not, then grouping individuals into natural kinds would have to be mind-dependent, and, what is worse from the point of view of the present task, the account of natural signification in terms of causality will be circular. (Presumably, the circularity would eventually amount to something like the following: a particular object o is represented by concept C if and only if it belongs to kind K; but o belongs to K if and only if o is represented by C.)

Now the very condensed argument of the paper makes it appear as if the only way for Ockham to specify the class of all particulars of the same kind having an equal ability to produce the same concept would be with reference to their causal powers to produce the same concept. But Ockham would emphatically deny this claim. As even the paper points out, for Ockham similarity is a real relation. That two particulars do or do not belong to the same species is a matter of their nature. They either are or are not co-specific, regardless of whether there is any human mind to form a specific concept that does or does not equally apply to both. Therefore, if they are co-specific, then of course they are apt to give rise to the same specific concept in the same human mind. But that they are co-specific is by no means dependent on the having, let alone the exercise, of this causal power; rather, it is the other way around.

So, apparently, the burden of Ockham’s account of natural signification in terms of causality will have to be carried by a nominalist account of several particulars’ belonging to the same kind regardless of the consideration of the intellect. But the possibility of such an account is not ruled out by the objection of circularity.

Indeed, it is not ruled out by the next objection either. But then the rhetorical question of the objection concerning Socrates and a tomcat, namely, "Why should they produce the concept of animal rather than the concept of male?", need not spell trouble for Ockham’s account. For Ockham might simply reply that Socrates and the tomcat have the causal powers to give rise to both sorts of concepts, since they belong both to the kind of animals and to the kind of males. And there is nothing problematic in the claim that only one of these kinds is an essential kind, giving rise to a generic concept, while the other is not, and thus it gives rise to a connotative concept. (For the sake of simplicity we can assume here the otherwise controversial claim that the concept "male" is a simple connotative concept, signifying males by simply connoting their vis generativa. Of course, if it is a complex concept, then its signification will depend on the signification of its components, and not on some direct causal contact with its objects.)

All in all, none of the objections of the paper considered so far seems to have delivered a fatal blow to Ockham’s account of natural signification. This does not mean, however, that Ockham’s account actually works. Indeed, despite their ineffectiveness taken in themselves, these arguments taken together are very helpful in delineating the minimal requirements that an acceptable answer to the original question should meet.

Most importantly, one such requirement is that our concepts should represent particulars belonging to the same kind in that respect in which these particulars should be similar in order to belong to the same kind. Otherwise a concept could not represent all individuals of the same kind on the basis of acquaintance only with a limited number of them, since it has no direct causal contact with any of the "new" particulars, and its contact with the "old" ones cannot serve as the basis for representing the "new" ones, for it does not represent them in that respect in which the old ones are naturally connected to the "new" ones. But if it does represent these particulars in that respect in which they are similar insofar as they are members of the given kind, then, clearly, any "new" particular of the same kind will be represented by this concept in the same respect, so it will be represented by this concept despite the lack of a direct acquaintance with it, and so the concept can serve as the basis of induction over individuals of the kind in question.

But once this requirement is made explicit, it is easy to see exactly why Ockham’s account cannot meet it. As we could see, talking about similarity in certain respects need not pose an immediate threat to Ockham’s nominalism, as it need not necessarily involve commitment to "abstract entities", that is, extramental universals. But Ockham also claims that absolute terms signify or represent their objects absolutely, that is, not in respect of something, indeed, not even in respect of something not really distinct from themselves. So, regardless of the fact that the notion of similarity in some respect would still be available to him, and thus he could allow that concepts are similar to, and hence represent, their particulars in some respect, his account of absolute concepts is incompatible with the above-described requirement.

Therefore, it is no mere coincidence that the author of the Logica Realis contra Ockham explicitly states that Ockham’s division of terms into absolute and connotative is mistaken (c. 9), for even absolute terms have to signify whatever they signify in respect of something, despite what Ockham says. A similar point is raised also by a later realist, Domingo Soto (Summulae lb. 1, c. 7).

Indeed, Soto’s case very clearly shows that the most fundamental disagreement between realists and nominalists is not ontological, but semantical. For Soto retains the semantic distinction between that which an absolute term materially signifies, which he calls its material significate, and that in respect of which it signifies its material significate, namely, that which it formally signifies, and which, therefore, he calls its formal significate. Still, Soto denies any ontological distinction between the two (In Praedicamenta, c. 5, q.1), and so, despite his "realistic" semantics, he ends up with the same ontology as the nominalist Jean Buridan. In fact, Soto’s and Buridan’s only ontological difference from Ockham is their common refusal to identify quantity with substance. But they still can endorse the same ontology, despite their radically different semantics. However, it is precisely their semantical difference that accounts for the fact that Soto’s theory is still compatible with the above-mentioned requirement, whereas Buridan’s, just like Ockham’s, is not.

Therefore, it seems that what is really at the bottom of Ockham’s failure to give an acceptable answer to the original question is not so much his nominalist ontology as his nominalist semantics of absolute concepts. Admitting some formal aspect under which such a concept would represent its objects may have appeared to him "dangerously" close to admitting something like an "obscure" formal distinction between the object and its nature. So Ockham abandoned the very idea that an absolute concept should represent or signify its objects under some respect. However, by this move he made himself incapable of giving an answer to our original question. In fact, he may have thought that that is a small price to pay. After all, he would not be the only, and certainly not the last nominalist who, instead of trying to give an answer to it, would challenge the legitimacy of the question. But in view of the foregoing considerations it seems that whoever finds the question legitimate should seek an answer not in the direction of a "more robust nominalism", but rather in the direction of an ontologically moderate, semantic realism.