William was born in Ockham, near London, perhaps in the year 1285, but certainly between 1280-1290. No definite information about his early life is had except that he joined the Franciscan Order while quite young and began his studies at Oxford, where he received his master of theology degree before 1320. The story that he studied under Scotus at Oxford seems just that, a story. This is not to say that Ockham was not heavily influenced by the writings of Scotus. Ockham's career at Oxford was cut short; at the completion of his lectures on the Sentences he was not awarded a teaching chair at the university. Indeed, the chancellor of the university accused Ockham of teaching dangerous and heretical doctrines. This accusation was made at the papal court in Avignon in 1323, and William was summoned there in 1324 to answer the charges. He spent four years at Avignon while a commission of theologians considered his case. During these years William continued to write, both treatises and commentaries, and he may have entertained quodlibetal questions at Avignon. The assumption is that he spent these years at the Franciscan convent there. It was during this period that William was caught up in the debate within the order concerning poverty. The dispute soon became one between the master general, with whom William sided, and the pope, John XXII. When the dissenting Franciscans fled Avignon to avoid papal censure, they sought the protection of the German emperor, Louis the Bavarian. It should be said that Ockham's opposition to the Pope was based on his judgment that the current Pope was in conflict with earlier papal pronouncements on the matter in question. Unfortunately, the appeal to the Emperor made the matter political as well as theological. In 1328 the Pope convoked a general chapter of the order and demanded that the Franciscans elect a new general. It was at this point that William fled Avignon in company with the general and other leaders of the opposition to the Pope. The upshot was that William and the others were excommunicated both by the Pope and their fellow Franciscans. Ockham settled in Munich and, after John XXII's death in 1334, continued his opposition to the Avignon popes. In 1347 Louis of Bavaria died, and Ockham sought reconciliation with the pope and his order. A formula of submission has survived, but we do not know the outcome of this effort at reconciliation. Ockham died in 1349 and was buried in the Franciscan church in Munich. He is thought to have been a victim of the Black Plague.
Ockham's difficulty with the papacy led to a series of writings on political themes; our interest is in the philosophical and theological writings, all of which were perhaps written during his Oxford and Avignon periods. His theological works include, of course, a commentary on the Sentences, quodlibetal questions, writings on the Eucharist and predestination. He commented on Aristotle's Physics and composed a number of allied works. Of particular interest are his writings on logic, which consist of commentaries on Aristotle and also various independent logical treatises.
A fair notion of Ockham's importance can be had by considering his rejection of previous medieval solutions to the problem of universals. What he has to say here has ramifications throughout his doctrine, ramifications which set him definitively aside from his great predecessors and put philosophy and theology on a new track, the via moderna.
The problem of universals, as we have seen, requires for its solution the introduction of logical, epistemological, and ontological considerations. As the problem was transmitted to the Middle Ages by Porphyry, the options for solution were the Platonic and Aristotelian. At first blush the choice may seem to be between a theory which admits more than individuals and one that does not; rather, it should be said that the difference resides in Plato's admission of a class of individuals beyond sensible, material individuals, namely, the Ideas, and that Aristotle's criticism of Plato comes down to a rejection of the imposition on any extramental individuals of the mental relations established by our act of knowing. If we confine ourselves to the Aristotelian viewpoint, one according to which the world is a world of individuals (to be is to be one), the further question arises as to what it is in individuals that permits us to form universal concepts and that in turn can lead to asking after the grounds of real similarities among existing individuals. There seem to be certain checks and controls exercised by individuals over our tendency to generalize. In one sense, it seems possible to group individuals in any way that pleases us, whatever their "real" similarities or dissimilarities (for example everything in this room), but, on the other hand, with respect to certain kinds of questions that we address to reality, our generalizing or grouping seems constrained by the way things are. The range of questions relevant to the Aristotelian conception of demonstrative science and the Porphyrian tree exercised great influence over medieval discussions of the problem of universals, a fact that accounts both for the undeniable precision of many of the solutions proposed as well as for the suspicion that a number of allied and difficult issues are being overlooked.
The problem of universals was most often discussed in terms of common nouns like "man" which occur as predicate in such a list of statements as the following: (1) Socrates is man, (2) Plato is man, (3) Aristotle is man, and so forth. If the predicate in these sentences does not refer to some individual other than those denoted by the proper names which function as subjects, it would follow that what "man" means is found in Socrates, Plato, Aristotle, and so forth. That is, we employ "Socrates" and "man" to talk about the same thing, and yet when we use "man" to talk about that thing we are not thinking of it in the same way as when we employ "Socrates." That is, sentence (1) above is not a roundabout way of saying, "Socrates is Socrates." If it were, of course, sentence (2) could be taken to mean that Plato is Socrates. As this was thought about, the tendency was to say that such common nouns express, not what is peculiar to Socrates and Plato, but what is common to them. But, obviously, "man" does not mean "what is common to Socrates and Plato," and this aspect of community (another term for universality) came to be located in the mind of the knower. "To be said of many or to be said of many numerically different things," which are less and more specific ways of explicating universality, were thought to be what happens to a nature, say human nature, as it is known by us. This led Aquinas and Scotus, though with notable differences, to the notion of a common nature, or rather to a nature not yet modified by universality or by individuality. Human nature is individuated in Socrates, Plato, and so forth, and it is universalized, that is, taken to be some one thing that is predicable of many individuals. Once more, "to be predicable of many individuals" is no part of the meaning of "man" it is not a constituitive of human nature, and as an accident of that nature universality was seen as something conferred by the human mind. Individuation, on the other hand, while equally accidental to human nature, for Aquinas is conferred not by mind but by matter with quantitative designations.
If universality as such was considered to be not part of the furniture of the extramental world, this is not to say that the natures to which it is attached in our knowing are not really different. The difference between a man and a horse, for example, was not considered to be the result of our mode of knowing; rather the difference is there awaiting our recognition. Another sort of difficulty arose in terms of an ascent of the Porphyrian tree, one that led to a difference between Scotus and Thomists, if not precisely between Scotus and Aquinas. Once we notice that the individual referred to by "Socrates" and man in our sentence (1) above can also be referred to by a number of other predicates, like "animal," "living thing," and "substance," predicates which are arranged hierarchically on the Porphyrian tree, the question arises as to what in the individual permits this variety of cognitive "fixes" on it, fixes which are explained in terms of greater and lesser universality. Are they grounded on real slices in the thing, so to speak, on formal differences, or do they rather attest to our mode of knowing, which proceeds from confused to less confused knowledge of things?
Perhaps these few words will be sufficient to recall the context of the problem. The solution that has been dubbed "moderate realism," Aquinas' solution to the problem of universals, would hold, from a logical point of view, that "predicability of many" is a logical relation consequent on our mode of knowing, from an epistemological point of view, that the concept of human nature, to which universality attaches, answers, with respect to its content, to a nature really found in various individuals, but that our concept prescinds from the marks of individuation and thus is not commensurate with individuals as individuals. Finally, from a metaphysical point of view the source of such a nature really found in many individuals would be sought in God, and reference would be made to the divine Ideas since the various natures in the created world are different expressions of God's awareness of his own imitability. What now of Ockham?
We cannot avoid the fact that Ockham's position on this problem is described as nominalist, but we must emphasize that the use of such tags does not provide us with a clear and distinct notion of nominalism which can then be blithely applied to Ockham. It is far wiser, having noted that Ockham is called a nominalist, to go on to examine what he had to say, with the idea that the results of such an inquiry will provide us with at least one sense of "nominalism." There is little doubt that Ockham wishes to discard the epistemological and ontological dimensions of earlier medieval discussions of the status of universals. In a fashion that is, or at least has become, characteristic of his countrymen in philosophy, Ockham exhibits an empiricist bent that leads him to want to ground whatever he says on individuals and his experience of them. Here we may mention another cliché of treatments of Ockham, namely, that famous razor. The formulation that is so much cited, entia non sunt multiplicanda praeter necessitatem, does not, as it happens, occur anywhere in Ockham's writings, but that is really of little importance. His spirit is summed up in that dictum: let us never introduce more than is required for an explanation. Parsimony in the apparatus of explanation is a mark of Ockham fully evident in his discussion of universals.
In his criticism of the position just sketched Ockham goes right for the jugular, that of a human nature really present in many individuals. Why should we speak of that nature as in some way awaiting individuation as it awaits the universality conferred by the mind? The world is a world of individuals through and through; the nature is not something distinct, in reality, from its individuating characteristics. If the nature predicated of Socrates does not include those individuating characteristics without which Socrates is not, well then we are saying of Socrates that he is what he is not. The natura absolute considerata of which Aquinas speaks, the nature regarded without reference to universality or particularity, such as human nature in itself, is, if not a fiction for Ockham, certainly nothing he considers deserving of serious attention. The crux of the matter for him seems to be that he can proceed very well without making any reference to a natura absolute considerata (it is this that commentators have in mind when they speak of the "common nature"). Universality and individuation can be handled as purely logical problems; they attach to language and consequently to thought, and the problem of universals becomes the logical problem of the behavior of common and proper names. The logical explanation should make no reference to unindividuated natures which are somehow in individuals (there are no such natures); consequently, the logical explanation need not bother itself with reference to the mind's ability to abstract such a nature from its individuating conditions. There is, nonetheless, an epistemological problem: How does our mind form universal notions against the background of its experience with a world of individuals?
With Ockham it is not so much the terminology of explanation that changes as the sense of the terms used. Thus Ockham will speak of abstractive knowledge, which he contrasts with intuitive knowledge, and we must achieve an understanding of this distinction. By intuitive cognition Ockham means a judgment whereby it is evident that the object exists or does not exist. He does not mean by intuitive knowledge sense perception, since the knowledge involved is intellectual, but the object of intuition is present existent fact. This description must be modified in two ways. First, it is taken to include what might be called negative facts, for example, that something does not exist or that it does not have such and such a quality. Second, Ockham admits the logical possibility of an intuition to which no existent fact corresponds, a possibility allowed to accommodate the divine omnipotence, since Ockham holds that God could cause us to have an intuition of a nonexistent object. This possibility is taken to have been realized in cases of prophecy, when God causes men to have intuitive knowledge of facts which do not yet exist. A further modification of the meaning of intuition for Ockham must be introduced when we find that he includes mental states among the objects of intuitive cognition.
Abstractive knowledge is described by way of contrasting it with intuitive cognition. A first description of abstractive cognition, accordingly, would be that it is such that it provides no evident knowledge that its object exists or does not exist. Further, abstractive knowledge is said to follow on intuitive cognition. If I have known the color of a particular rose, I can later think of that rose and its color even without the presence of the fact. Such cognition does not permit me to say that the rose exists, however, since it may have ceased to do so. Abstract knowledge, for Ockham, is the pale reflection of intuitive cognition.
It is the concept's loss of sharpness and particularity in abstract cognition that provides Ockham with his understanding of the nature of universality. The remembered and abstractly thought-of rose, in losing the particular notes of the once-seen rose, involves a concept answering to the term "rose" that is vague enough to apply to several roses. Notice that this explanation requires no distinction in the particular rose between its thisness and its rosehood; that transition is explained solely in terms of types of human thought and in no wise prejudices a world of individuals through and through. Abstract knowledge expressed in judgments involving universal concepts makes no assertion with respect to factual existence; only when linked with a judgment of intuitive cognition is such a claim involved. Ockham's treatment of supposition corresponds to this duality.
Has Ockham really bypassed the solution to the problem of universals dubbed moderate realism? This question is bound to impose itself when we find that when Ockham asks why in abstractive cognition we form a concept of rose that is not tied down to a particular rose as known in intuitive cognition and which can be applied to many and indeed all roses, he replies that the concept fastens on to the similarity between actually existing individual roses. Now this similarity is real, and that was the fundamental motivation for the introduction of the so-called common nature, that is, the natura absolute considerata. Ockham will reply that he is not appealing to a common nature, but of course, as Aquinas' presents the solution of moderate realism, the nature is not actually common or universal in individuals; rather, the real similarity among individuals is the foundation in reality of the one nature expressed in the concept to which attaches the relation of predicability to many. Ockham's demur here may seem to us to be anything but persuasive, and yet it would be quite mistaken to conclude that Ockham's nominalism turns out to be identical with Aquinas' moderate realism. "Every man is risibile" has interest and importance for Ockham only because it is a roundabout way of saying that Socrates is risible, Plato is risible, Aristotle is risible, and so on. For a thinker like Aquinas the universal judgment would not be formed if we did not have experience of some men, but the universal judgment is not merely a shorthand expression for an open series of singular and contingent judgments. Ockham may finally have confessed that universals constitute an occult problem, but rather than construe this confession of difficulty with a wavering toward moderate realism, we must see that it goes hand in hand with an attitude toward knowledge, toward contingency and necessity, which tends in the direction of a radical empiricism of individual fact and away from an empirically grounded thought whose telos is universal and necessary judgments which involve a qualitative move beyond judgments of particular existent fact. It is not without reason that commentators have expressed Ockham's view of the universal judgment as an open sentence, a propositional function, according to which "Every man is risible" becomes "For all x, if x is a man, x is risible," a translation that makes no ontological commitment to the effect that there are values for x, and which suggests that if there are such values, the meaning of the universal statement is the sum total of relevant judgments of individual fact.
The new or terminist logic of the fourteenth century, of which Ockham is an adherent and not the founder, does not differ from earlier medieval logic in being divorced from metaphysical and epistemological considerations. Indeed, as we shall see, many of the moves that Ockham makes in logical theory are dictated by his metaphysical and epistemological views.
Ockham gives three senses of "term" and concludes that its precise meaning is such that it is a term which can be either the subject or the predicate of a proposition. "Term" requires a broader sense when we wish to distinguish between categorematic and syncategorematic terms. Of the former, Ockham says that they have a definite and fixed meaning, and his examples are "man," "animal," and "whiteness." The latter, syncategorematic terms, are exemplified by "every," "none," "some," "only," and so forth. These are said not to have any definite and fixed meaning, nor do they signify things distinct from those signified by categorematic terms. "Every" attached to "man" makes the term man stand for all men; when attached to "stone" it stands for all stones.
In distinguishing between absolute and connotative terms Ockham wants to draw a difference between those which signify primarily and have no secondary signification and those on the other hand that have a primary and secondary signification. An example of the latter, of a connotative term, is "white." If we ask what "white" means, we may be told that it means "something that has whiteness," and thus it means both the quality and its bearer. Where Ockham's ontological penchants become clear is in his discussion of absolute terms, terms that signify substances. He does not want to say that "man" signifies the nature humanity and its bearer, since this conjures up for him the whole business of the common nature. This leads him to the view that "man" signifies all men and "animal" signifies cows, horses, asses, men, and so on. Away with animality and humanity as id quod nomen significat, and we are left ultimately only with individuals. Ockham will insist on the importance of supposition, a doctrine that may be seen to foreshadow contemporary distinctions between meaning and reference, but on crucial occasions, and influenced by his nominalism, Ockham comes very close to identifying meaning and reference. It seems difficult to see that he is doing anything else when he says that "animal" means what it can stand for. He actually defines supposition as the use of a term in a proposition for some thing or things, and normally for the things it signifies. And although he employs the standard distinction between material supposition (for example, "Man is a noun"), simple supposition (for example, "Man is a species"), and personal supposition (for example, "Every man is an animal"), when he speaks of personal supposition, which is the chief kind, he defines it as obtaining when a term stands for what it signifies and is used in its significative function. His doctrine of meaning becomes his doctrine of supposition or reference; logically, what absolute terms mean are individual things because, metaphysically, the only things that are are individual substances and individual qualities. We may no longer find such logical atomism quaint, but it must be insisted that Ockham represents a significant break with the philosophy of logic of the thirteenth century and that, in his case, his logic goes hand in hand with his metaphysics. It is not for us to ask now whether the logic Ockham clearly foreshadows is accidentally or essentially linked to an impoverished metaphysics.
The criticism of Ockham is not that he has no metaphysics but that he has an excessively diminished one. The basis for this criticism can be seen by asking how Ockham deals with the questions of classical metaphysics, but in this sketch we will confine ourselves to what he has to say about the subject of metaphysics.
That subject, of course, is being as being. Ockham's general approach to metaphysics is by way of criticism of the views of his predecessors, views he conceives to be fraught with confusions he is able to avoid. There is no surprise nor indeed novelty in Ockham's reminder that being as being is not some individual entity apart from other beings, but what is distinctive of him is his contention that being is univocal in such a way that it applies in a wholly undifferentiated way to whatever is and, of course, whatever is is an individual. There is nothing whatsoever that mediates the maximum universality of the term "being" and this or that individual to which it can be applied. By the same token, it stands for accidents in a direct and unmediated way. This is what Ockham means by saying that it is predicated in quid. Given our earlier discussions, we can assume that for Ockham the meaning of "being" is all actual existents, and no doubt this is at the basis of his rejection of the distinction between essence and existence. Ockham's simplistic interpretation of the views of others goes hand in hand with his contemptuous disdain. It is difficult to take too seriously one who reminds others that existence must not be understood as a qualification of what does not exist, for he thereby seems to suggest that "essence" means nothing and "existence" existence and that his predecessors had held that being (ens) is a nothing which exists. His treatment of the distinction between actuality and potentiality is equally profound; a possible being, he seems to think, was taken to be an existent nonexistent. His prescription for avoiding such undocumented paradoxes is that we learn that actuality and possibility are modalities of statements and not of things. This, while possessing the allure of a partial truth, since the characteristics of modal propositions are not precisely the characteristics of things, far from providing an alternative answer to a question asked earlier, fails even to raise the question. The principle of parsimony is here running amok. To say that Socrates can pitch a curve is not the same as to say that it is possible that "Socrates is pitching a curve is true. Ockham may seem to be saying that the latter is not the former, but what he is really saying is that the former need be taken to mean exactly the same thing as the latter. There remains little doubt as to who is confusing modalities of statements and characteristics of things, Ockham or his unnamed adversaries.
Once the univocity of being is understood in terms of a universe of things wholly undifferentiated in terms of their being, a veritable flatland of reality where the only solid truth is that an individual thing is itself, Ockham hurries on to show that this enables us to settle the question of God's knowability. There is no common feature in reality that the term "being" (or, in a more limited range, any other general term) is thought to pick out. Now, since this does not impede ordinary linguistic usage, being only an inadequate account of it, since we can go right on saying of Socrates and of Plato and so forth that they are men while denying that there is any foundation in reality other than their individuality, that is, their otherness, for so speaking, what is to prevent us from saying that God can be said to be, even though there is absolutely no common feature between God and anything else? In this Ockhamian wonderland everything is just itself and no other, whether we be speaking of creatures or of creatures and God. Lest our tone seem to be too strident here, we should say that it is one thing to discuss the behavior of common nouns without raising the allied epistemological and ontological questions -- this could result from mere boredom or lack of intellectual curiosity. It is quite another thing to go into a discussion of those epistemological and ontological questions and to say little more than that common nouns are common because they are common and then to lament the confusions of one's predecessors. Ockham does the second and quite different thing. And it is important to be very clear about the metaphysical results of his thought and, once we are clear about them, to lament them. A world where each thing is only itself and no other, where its very otherness is said to be its similarity with others -- well, this is a confused and paradoxical terrain. If we excuse ourselves from any consideration of Ockham's discussions of proofs of God's existence and proofs that God has certain attributes, we do so because his apparently affirmative results are such only when terms bear the peculiar Pickwickian sense according to which Ockham can predicate the same term of two entities while denying that he is doing anything other than pointing to two utterly different things. It is only when we forget Ockham's nominalism -- as he on occasion was prone to do himself -- that the results of his inquiries amount to something other than the melancholy one just stated.
A very useful anthology of Ockham's writings together with a helpful introduction is Ockham: Philosophical Writings, edited and translated by P. Boehner (New York, 1957); Boehner also edited the Summa totius logicae (St. Bonaventure, 1951-1954). See E. A. Moody's edition of Expositio in librum Porphyrii de praedicabilibus (St. Bonaventure, 1965). See too P. Boehner, Collected Articles on Ockham (St. Bonaventure, 1956) and E. A. Moody, The Logic of William of Ockham (New York, 1935).