“This Human”, Again

Stephen Ogden’s Averroes on Intellect (2022) is the first book-length treatment of this fascinating subject of medieval controversy that is centrally focused on an independent philosophical evaluation of the arguments of Averroes himself. Ogden develops a reading of Averroes in close relation both to the Aristotelian text and to the contrasting positions of Avicenna and Aquinas. Averroes, he says, deserves to be taken seriously both as a reader of Aristotle and as a philosopher in his own right. Averroes challenges us to question our assumptions as to what “intellect” might be.

Ultimately, Ogden suggests a sort of compromise between Averroes and Aquinas. This makes an interesting counterpoint to the interpretation of Deborah Black.

Like Black, Ogden highlights the common ground between Averroes and Aquinas. He develops the fact that unlike most earlier commentators on Aristotle, Averroes and Aquinas both explained actual and potential “intellect” in symmetrical ways that made them the same broad kind of being. They also both distinguished a third, “passive” intellect — said to be a kind of disposition of the human imagination — that others have often identified with the potential intellect.

Prior to Averroes, the most common type of reading made actual intellect a singular or universal cosmic or metaphysical principle, while treating potential intellect as something mortal and divided among many individuals. (While fascinating, this is to my mind anomalous with respect to the way Aristotle himself develops the relations between potentiality and actuality. I tend to think of these as only analytically distinguishable aspects, phases, or modes of the same real things.)

Averroes and Aquinas agree that both actual and potential “intellect” are immaterial things that are not dependent on the body. They both defend variants of what is termed “moderate realism” with respect to universals. In this kind of view, universals have reality independent of particulars, but they do not subsist in themselves as Plato thought. They are “abstracted” from human imagination by something called “intellect”.

On the other hand, Aquinas and Averroes approach the interpretation of “intellect” with very different concerns in mind. Ogden agrees with Deborah Black’s point that the role of intellect for Averroes lies in the constitution of intelligible objects. Further, for Averroes the universal singularity of “intellect” carries the whole burden of underwriting a non-Platonic reality of universals as universals.

For Aquinas on the other hand, I would say the primary role of intellect is to underwrite a metaphysically strong notion of personal identity. Aquinas uses a complex original theory of intelligible “species” to do most of the work of underwriting the reality of universals. This leaves him free to repurpose “intellect” as a basis of a philosophical argument for personal immortality that has no parallel in Averroes or Aristotle. Aquinas develops a nuanced account of how the soul exists in genuine union with the body, but each individual soul contains within it intellect that is separable from body. For Aquinas, the presence of intellect within the soul guarantees the immortality of the soul. Ogden mentions in passing Aquinas’ acceptance of Aristotle’s view that memory, however, is inseparable from the body.

Ogden agrees with Black that Averroes successfully explains the experience of human self-awareness in terms of imagination, without needing to appeal to intellect. But Ogden says that for Averroes, in a stricter sense it is indeed only the intellect as our perfective form that “understands”, so perhaps we should say that thought happens within us, rather than that we think.

He mentions that Bertrand Russell said that Descartes should have said “there is thought”, rather than “I think”. I would add that “I” am not a “thinking thing”, but an ethical being constituted by my commitments and practices of commitment.

Ockham on Reference

William of Ockham (1285-1347) is the most famous so-called “nominalist” in Latin medieval philosophy. He sought to explain our practical and theoretical uses of universals entirely in terms of our relations to existing singular things.

Without losing sight of Plato’s emphasis on the value of pure thought, Aristotle had adopted a broader perspective, starting from the generality of human life. In this context, in contrast to Plato he had emphasized the genuine importance, positive role, and irreducibility of singular beings or things that we encounter in life. “For us” singular beings and things come first, even if they do not come first in the order of the cosmos.

Singular beings and things are more concretely “real” than any generalizations about them. But Aristotle simultaneously upheld the “Platonic” view that knowledge in the strong sense can apply only to generalizations of necessary consequences between things, and not to our experiences of singulars. There can be no necessity in our experience of something purely singular. What I would call the extraordinarily productive tension between Aristotle’s fundamental views of reality (putting singulars first) and of knowledge (putting universals first) created an appearance of paradox that later commentators sought to resolve, often by favoring one side at the expense of the other.

Ockham wanted to explain universals entirely in terms of singulars. In the Cambridge Companion to Ockham, Claude Panaccio summarizes that “Ockham’s project is to explicate all semantical and epistemological features — truth values, for instance — in terms of relations between sign-tokens and singular objects in the world” (p. 58).

Ockham built on the work of many less well-known figures. The Latin world had seen lively inquiries about logic and semantics since the 12th century, when Arabic learning first began to be disseminated across Europe. Within this tradition, there is more than one approach to meaning.

The technical notion of “signification” was a development inspired largely by Augustine’s theory of “signs”. Unlike more recent usages (e.g., in Saussurean linguistics), this kind of signification involves a simple relation of correspondence between a thing taken as a “sign” and some other thing.

Ockham and many of his predecessors held that there is such a thing as natural signification, independent of any language. In this sense, smoke is taken to be a “sign” of a fire. This relation of smoke signifying fire is called “natural”, because in our experience smoke only exists where there is fire, and this has to do with how the world is, rather than with us. This is very different from the conventional imposition of the word “fire” to refer to a fire.

At the same time, this notion of signification also seems to have an irreducible “psychological” component. It has something to do with how the world is, but in a more direct sense, it has to do with something like what the British empiricists later called the association of ideas. Our “natural” association of smoke with fire is not arbitrary. As the empiricists would say, it is grounded in experience. As the Latin scholastics would say, the soul “naturally” tends to associate smoke with fire, and this is as much a truth about the soul — or about the soul existing in the world — as it is a truth about the world.

For Ockham, natural signification applies to concepts, which constitute the core of a sort of “mental language” that is in many ways analogous to spoken or written language, but is more original and does not depend on convention. Concepts on this understanding are subject to all the same kinds of syntactical relationships as individual words in speech.

In this tradition, the meaning of concepts is analyzed by analogy with the role of individual words in speech. This presupposes a view that linguistic meaning overall is founded on the meanings of individual words. The individual concepts of “mental language” that apply to individual real-world things are analogously supposed to have pre-given, natural meanings. Logic and semantics are then a sort of mental hygiene with respect to their proper use.

Ockham offers a rich analysis of connotative terms that modify the concepts corresponding to things.

Again building on the work of many authors in the Latin tradition, he develops the theory of logical “supposition”, which contemporary scholars associate with semantic discussions of reference to real-world objects. This has nothing to do with supposition in the sense of hypothesis; rather, it relates etymologically to a notion of something “standing under” something else.

Notably, Ockham and this whole tradition insist that while individual words independently have signification, only in the context of propositions or assertions expressed by whole sentences do words have the kind of reference associated with supposition. I suspect this is ultimately grounded in Aristotle’s thesis that truth and falsity apply only to whole propositions or assertions; “supposition” is to explain not just meaning, but also truth and falsity. This tradition develops a much more explicit theory of reference than Aristotle did, and the kind of reference it develops is tied to contexts of assertion, or true assertion.

The idea that reference to real-world things should be approached at the level of propositions rather than individual words or concepts has much to recommend it. But for Ockham and the tradition he continued, supposition is still fundamentally governed by signification, and signification begins with individual words or concepts. Individual words or concepts are thought to have pre-given meanings, and Ockham attempts to give this a theoretical grounding with his notion of “mental language”.

As Ockham suggests, there is a way in which notions of syntactic relations apply to pure concepts. But I take this to be an abstraction from actual usage in spoken or written language, and I don’t believe in any pre-given meanings.

Ockham’s general strong privileging of individual things over universals has a deep relation to his voluntarist and fideist theology, which owes much to his fellow Franciscan Duns Scotus. In logic, Scotus is considered a defender of “realism” about universals as opposed to nominalism, but in his theology he developed a strong notion of individuation, tied to a very radical notion of divine omnipotence that refused to subordinate it in any way, even to divine goodness (see Aquinas and Scotus on Power; Being and Representation). Essentially, from this point of view, every single thing that happens is a miracle coming directly from God, and all observed regularity in the world pertains only to a sort of divine “habit” that could be contravened at any moment.

Aquinas aimed at a sort of diplomatic compromise between this extreme theistic view that makes everything solely dependent on God, and Aristotle’s unequivocal assertion of the reality of “secondary” causes. Scotus and Ockham applied high levels of logical sophistication in defense of the extreme view.

Ockham also denied the reality of mathematical objects. Together with his extreme view on divine power, this makes very unlikely the view promoted by some scholars that Ockham in particular represented the strand of medieval thought that most helped promote the emergence of modern science. Ockham’s undeniable logical acumen was dedicated to downplaying rather than elaborating the practical importance of order in nature.

It does seem, though, that views like Ockham’s contributed to the shaping of British empiricist philosophy. Here is another chapter in the complex history of notions of reference and representation. Ockham’s very strong notion of reference as directly grounded in singular real-world objects — combined with that of the natural signification or pre-given meaning of concepts in “mental language” — helped lay the ground for what modern empiricism would treat as common sense.

For most of the 20th century, the mainstream of analytic philosophy seemed to be inseparable from a strongly empiricist direction. But Wittgenstein, Quine, Sellars, Brandom, and others have initiated a new questioning of the assumptions of empiricism from within contemporary analytic philosophy. Analytic philosophy is no longer nearly so opposed to the history of philosophy or to continental philosophy as it was once assumed to be. It is in this context that we can begin to look at a sort of Foucaultian or de Libera-esque “archaeology” of empiricism, in which Ockham certainly deserves an important place.

Peter Abelard

Peter Abelard is widely regarded as the greatest philosopher and theologian of 12th century Europe. He flourished right before the great influx of translations to Latin from Arabic and Hebrew.

For Abelard, common names refer collectively and directly to many individual things, and there are no separate universal things apart from individual things. But in addition to reference, words have signification, or practical informational content.

The signification of sentences, moreover, cannot be reduced to the signification of the nouns and verbs that make them up. Sentences convey irreducible judgments (dicta) about how things are. Abelard has been said to hold an adverbial view of thought.

He opposed two simplified views of understanding commonly attributed to Aristotle in the tradition: that the mind literally takes on the same form that it apprehends, and that images in the mind resemble the things it apprehends.

Abelard endured persecution for opposing the proto-fundamentalist view of Bernard of Clairvaux that sentences about the faith have a “plain meaning” that is beyond question. He also openly acknowledged that Church authorities contradicted one another on numerous points. At the same time, he is said to have rejected views he attributed to his teacher Roscelin that human reason can explain everything; that we should not accept anything that cannot be explained by reason; and that authority has no rational force.

Abelard reportedly held that the agent’s intention alone determines the moral worth of an action, and that obedience to God’s will consists in applying the Golden Rule (“Do unto others as you would have them do unto you”). Only God has the right to morally judge others. Ethics is not a matter of acting in conformity to law. Nonetheless, human law may legitimately disregard good intentions in punishing actions that had genuinely bad consequences, as a lesson to others.

In Genèse du dieu souverain, Gwenaëlle Aubry says Abelard devoted considerable energy to combatting the notion of a “tyrant God”, citing Daniel’s confrontation with the neo-Babylonian tyrant Nebuchadnezzar. Here he seems to me to anticipate Leibniz in connecting theological voluntarism with tyranny. According to Aubry, Abelard argued that “God, if He is at once rational and good, can only choose the good. Further, a God who did not will and do all the good that He could would be not good but jealous. Therefore, God wills and does all the good that he can, and cannot do anything other than what He does do” (p. 123, my translation). “The essential point that separates Abelard from Augustine… is in effect the following…. it is not sufficient to say that divine action is governed by reason and by the good, rather it is also necessary to affirm that human reason can reason about that reason and that good” (ibid). Here again, on this account Abelard seems to anticipate Leibniz.

According to Aubry, Abelard quotes Augustine saying God is omnipotent “because He can do what He wills….[God] is all-powerful, not because He can do all, but because He can do all that he wills” (p. 124, brackets in original). From this Abelard argues that “It is necessary to say not that God could have done something but did not will to do it, but rather that what he does not will, he can in no way do. The scope of power is indeed not more extended than that of divine will…. [I]n God, power and will are united in such a way that where will is lacking, power is also lacking” (p. 125).

“In [Abelard’s] Theologia Christiana, omnipotence is defined as that for which the will suffices by itself to do all that needs to be done. Omnipotence is thus characterized not by an excess over its effects but by an adequation to them. Not that which is capable of more things than it does is omnipotent, but that which has the power sufficient to what it wills to do” (p. 126).

According to Aubry, Abelard insists on the immutability of divine power and action. Augustine too emphasized the eternity of God, which also implies immutability. But in general he treats the human mind as an image of God, whereas Aubry says Abelard warns against thinking about God’s power in terms of human power. In the works I am familiar with, Augustine treats human will as a power of choice. Is divine will a power of choice too for Augustine, or is it the definite will Aubry suggests Abelard implies it is? I don’t currently know the answer.

Is there any way that power of choice could even have meaning for a genuinely eternal being? It has always seemed to me that choice implies temporal conditions that are incompatible with eternity.

Aubry says that referring to Plato’s Timaeus (a fragment of which was the only text of Plato available in Latin at the time), Abelard distances divine power from the creation from nothing with which it is strongly associated in Augustine, in order to associate it essentially with reason. According to Aubry, Abelard says this is not only the best of all possible worlds, but the only possible world, whereas Augustine says this world could be changed by divine will. Aubry relates this to the excess of divine power over divine will in Augustine.

She makes the Platonic-sounding point that Abelard in Theologia Christiana says not that God is by himself the good, but rather that the good is that which one calls God…. In this way, theology is subsumed by ethics rather than ethics by theology” (p. 130). Aubry also says Abelard transposes the principle of non-contradiction, the principle of excluded middle, and the principle of sufficient reason from the realm of ontology to that of axiology or values.

In both Theologia Christiana and Theologia Scholarium, Abelard raises the question, “Could God do more or better than He does, or again not do what he does?” (p. 133). He answers no, because to say yes would degrade the goodness of God.

Taking “Things” as True

The second standpoint examined by Hegel in the Phenomenology is Perception, or in the literal etymological sense of the German word for it, “true-taking”. This etymology has an intriguing but probably accidental resonance with the notion of taking things as thus-and-such that Brandom emphasizes in Kant. In Perception, emphasis is more on the things than on the taking.

Harris in his commentary associates Perception with the philosophy of healthy common sense. Even the peasant woman of the previous chapter “must follow the ‘leading’ of language at least one step beyond the naming of [things]. She identifies her cows not just by their names, but by their color-patterns; and she knows her apple trees from her plum trees or her neighbor’s peach, etc. Hers is a world not just of singular [things], but of perceptible types; but for her, the process of classification with its universal names is an instrumental shorthand for dealing with the ‘real things’ that can be identified and pointed to. She does not want to take the leading of language seriously, but only to get back to her life, and to get on with it” (Hegel’s Ladder I, p. 238).

Perception at least begins to take up the nuances of how things interrelate that are ignored by sense certainty. “Sense-Certainty is rich only in positive things to be certain of…. Only perception can say what is, because it names universal things that are perceived through the changing sequence and variety of their properties”(p. 239). “Perception is the being grasped together of the moments that unfold in perceiving as process…. The perceiving we are concerned with is a process in which the universal self takes itself to be a rational being, and the truth of its object to be a universal truth” (p. 238). By “universal self” he means an individual self taken as an instance of a rational self, not anything like a world soul.

Harris continues, “Our situation as philosophical observers is different in its ‘object’ from the perceiving consciousness. Our object has been logically determined for us, whereas the object of the perceiving consciousness simply ‘falls out of the world of Sense-Certainty’ for it… It knows that the object is a universal essence; but it does not know that ‘universality’ is an activity of the perceiving mind” (pp. 238-239).

We know that the ‘thing’ is a result of this process…. Our perceiving is the process, of which the object is the result. Perception… is an interpretation of sense-certainty in which the knowing consciousness is no longer concerned about the truth of the copula ‘is’, but about what is…. Sense-Certainty was already implicitly perception in its examples” (p. 239).

He quotes Hegel saying “Being is a universal in virtue of having mediation or the negative in it” (p. 240). As Harris says a bit later, “There is no nameable property of anything that is not part of a range of alternative properties. Some variations of properties are consistent with the thing continuing to count as the ‘same thing’ — and some are not” (ibid).

“[T]he singular property of ‘being salt’ is known to us as immediate sensation only when we taste it (and that is when the salt itself is necessarily dissolved back into the flux of sense-immediacy). Thus, in the white cube that is the ‘thing’ I perceive, the character of being salt is a not-this; it is not immediately sensed, but it is stably preserved for the sensation whenever I want to sense it…. It is a potentiality for sensation…. As this potentiality, this ‘otherness’ than what it is (the cubical whiteness etc.), it is a universal” (pp. 240-241).

(I am delighted to see Harris stressing the importance of potentiality in this crucial transition out of immediacy in Hegel. I don’t recall Hegel using the word “potentiality” much, but thought he ought to have.)

“What is ‘truly taken’ is an essence that is the negative ‘property’ which determines and holds together all the positive ones. But it is also truly taken as the positive property of filling a certain space. All of the properties cohere together in the space that the thing occupies…. ‘Thinghood’ as directly given for perceiving is the persisting spatial togetherness of many independent qualities…. The ‘thing’ is not just a loose collection of properties inhering somehow in the same identifiable region of space at the given time. It is a thing because of what it excludes; and its exclusiveness is what particularizes each of its properties” (p. 241).

“I know that I do not passively perceive what is true, in the way that I seem to apprehend the fact that ‘this is Lisa, and this is Ursel’ passively. My reflective capacities are involved. Perceiving is an activity of consciousness” (p. 245). “But it ought to be consistent” (p. 246).

“The attempt to claim that the manifold of sensation is simply subjective ignores its interpersonal objectivity. Every identifiable property is an objective essence…. Not just the oneness of the thing is objectively real, but its ‘difference’ from everything else” (p. 247).

“The essence of being a thing is to be ‘for another'” (p. 249). “Everything is specified by its difference from others” (p. 250). “The determinacy which is the ‘essential’ or ‘absolute’ character of a thing on its own account is essentially a relation to others (which negates the thing’s independence)” (p. 251).

Here we begin to see the limits of Perception. “The standpoint of Perception presupposes an absolute community of ‘things’. But the definition of ‘thinghood’ that the perceptual consciousness set up for itself contains no necessary reference from one thing to another for its being. The independent being of the thing is what makes it the ‘object’ that can be ‘truly taken’…. We have now seen that in any consistent formulation of the perceptual standpoint, this is logically impossible. It is the independence that is a sham” (p. 252).

“What is ‘essential’ and what is not ‘essential’ is a function of our supposedly external observation” (p. 253).

“Hegel… aims to show us that the naive empiricism which wants to conceive of perception causally (as analogous to mirror-reflection) cannot succeed.”

“We have already seen how we could not stand still at the concept of the ‘one thing’ with ‘many properties’. We had to admit that the multiplicity was founded in the ‘thing’, and not simply generated by the perceiving mind; and on the other hand, the ‘unity’ was an actively negative exclusion, which could not be simply contributed by the mind as it sorted the perceived ‘properties’ into things” (p. 254).

The standpoint of perception treats logic and philosophy as mere “game[s] with verbal counters” (p. 256). Its mistake is “to assume that ‘cognition’ is an activity that supervenes on an object that is already there; but actually it is the construction of ‘the object’ in a process of interpretation” (p. 257).

Searching for a Middle Term

“But nothing, I think, prevents one from in a sense understanding and in a sense being ignorant of what one is learning” (Aristotle, Posterior Analytics; Complete Works revised Oxford edition vol. 1, p. 115). The kind of understanding spoken of here involves awareness “both that the explanation because of which the object is is its explanation, and that it is not possible for this to be otherwise” (ibid). To speak of the “explanation because of which” something is suggests that the concern is with states of affairs being some way, and the “not… otherwise” language further confirms this.

Following this is the famous criterion that demonstrative understanding depends on “things that are true and primitive and immediate and more familiar than and prior to and explanatory of the conclusion…. [T]here will be deduction even without these conditions, but there will not be demonstration, for it will not produce understanding” (ibid). The “more familiar than” part has sometimes been mistranslated as “better known than”, confusing what Aristotle carefully distinguishes as gnosis (personal acquaintance) and episteme (knowledge in a strong sense). I think this phrase is the key to the whole larger clause, giving it a pragmatic rather than foundationalist meaning. (Foundationalist claims only emerged later, with the Stoics and Descartes.) The pedagogical aim of demonstration is to use things that are more familiar to us — which for practical purposes we take to be true and primitive and immediate and prior and explanatory — to showcase reasons for things that are slightly less obvious.

Independent of these criteria for demonstration, the whole point of the syllogistic form is that the conclusion very “obviously” and necessarily follows, by a simple operation of composition on the premises (A => B and B => C, so A=> C). Once we have accepted both premises of a syllogism, the conclusion is already implicit, and that in an especially clear way. We will not reach any novel or unexpected conclusions by syllogism. It is a kind of canonical minimal inferential step, intended not to be profound but to be as simple and clear as possible.

(Contemporary category theory grounds all of mathematics on the notion of composable abstract dependencies, expressing complex dependencies as compositions of simpler ones. Its power depends on the fact that under a few carefully specified conditions expressing the properties of good composition, the composition of higher-order functions with internal conditional logic — and other even more general constructions — works in exactly the same way as composition of simple predications like “A is B“.)

Since a syllogism is designed to be a minimal inferential step, there is never a question of “searching” for the right conclusion. Rather, Aristotle speaks of searching for a “middle term” before an appropriate pair of premises is identified for syllogistic use. A middle term like B in the example above is the key ingredient in a syllogism, appearing both in the syntactically dependent position in one premise, and in the syntactically depended-upon position in the other premise, thus allowing the two to be composed together. This is a very simple example of mediation. Existence of a middle term B is what makes composition of the premises possible, and is therefore what makes pairings of premises appropriate for syllogistic use.

In many contexts, searching for a middle term can be understood as inventing an appropriate intermediate abstraction from available materials. If an existing abstraction is too broad to fit the case, we can add specifications until it does, and then optionally give the result a new name. All Aristotelian terms essentially are implied specifications; the names are just for convenience. Aristotle sometimes uses pure specifications as “nameless terms”.

Named abstractions function as shorthand for the potential inferences that they embody, enabling simple common-sense reasoning in ordinary language. We can become more clear about our thinking by using dialectic to unpack the implications of the abstractions embodied in our use of words. (See also Free Play; Practical Judgment.)

Nominalist Controversies

Especially in the 14th century, controversies associated with the opposition between nominalism and realism greatly exercised philosophers and theologians in the Latin West. These terms have been been variously understood, but as a first approximation, nominalism wants to deny claims about the real basis of abstractions that the realism of this context wants to affirm.

In this case, a polar opposition is concealed behind a pair of concrete terms (nominalism, realism), where in context one is understood as the simple negation of the other. As usual with debates around distinctions based on polar opposition rather than more limited and definite determinate negation, the greatest interest often lies in the way each side tries to recover something like the strong points of the other side, but in its own terms.

These controversies are worth lingering over for several reasons. For one thing, they help illustrate the great diversity, subtlety, and liveliness of medieval thought. For another, they develop many fine distinctions that are of lasting value in talking about human knowledge and understanding. We would all like to rightly apprehend things, whatever that means. The waters are commonly muddied not only by insufficient distinctions among things, but also by fundamental unclarity or ambiguity on the meaning of “existence” or “reality”, which gets worse where abstract things are involved. Who we might think was right in the debates is of secondary importance compared to clarifications of this kind. Finally, these debates involved much discussion of mental representation, its origins, and its role in thought.

Speaking with very broad brush, nominalism begins as a critique of a sort of “platonism”. Such platonism wants to say the universal is more real than the particular. It may go on to claim that abstract entities are as real as — or more real than — concrete ones. It may extend to further claims that universals simply “exist” in some pure way, independent of space and time. Nominalism in general wants to say the opposite, that universals are actually not real at all.

Aristotle already criticized platonist views of the sort just mentioned, while still maintaining that the development of universals is essential to knowledge. I think that in the big picture, he wanted to recommend an essentially even-handed approach, recognizing both universals and particulars as necessary to any developed view of experience, while pointing out their very different and complementary roles. Whatever we may think about the reality or unreality or existence or nonexistence of given things or of various kinds of things, we need universals to support the implicit reasoning standing behind any developed knowledge. We also need particulars as practical starting points, and as cross-checks to keep us honest. This does not yet make any claim about reality or existence that might support such needs. Aristotle often practiced a careful minimalism, sticking to essentials and leaving other questions open, and this is a good case in point.

Albert the Great and Thomas Aquinas wanted to develop Aristotle’s position into a firmer doctrine, classically called moderate realism. Most people agree that Aristotle thought universals do not “exist” independently of particular things and thought. Albert and Thomas argued that implicitly, what Aristotle said committed him to 1) a claim that universals are real and 2) a claim that universals exist, but only in concrete things and in thought.

Nominalists especially disputed the claim that universals exist in concrete things. They most commonly advocated a mental origin of universals, while differing on the precise status attributed to them. Already in the 12th century, Roscellinus had argued that universals are mere names (root of the word “nominalism”). Whether or not the great Peter Abelard should be interpreted as a nominalist or a middle-of-the road “conceptualist” is contested among scholars.

The theologian William of Occam (1285 – 1347) was the most famous medieval nominalist. Early in his career, he argued that universals were ficta (“fictions”) of the mind. Later, he worried that this still tacitly presupposed they were representations, which would seem to still imply something corresponding to them in external objects. He then argued that external objects have causal impact on the mind, but not by representation.

The important secular master John Buridan (1301 – 1358) is usually also called a nominalist. Buridan was one of the leading logicians of the middle ages, and wrote on a wide range of philosophical questions. He had several noteworthy students who are also considered nominalists, including the logician, natural philosopher, and bishop Albert of Saxony (1320 – 1390). Marsilius of Inghen (1340 – 1396) was another nominalist who wrote on logic, natural philosophy, and theology. The theologian Gregory of Rimini (1300 – 1358) is also considered a nominalist.

The great theologian John Duns Scotus (1265 – 1308) was a commited realist who nonetheless influenced Occam on some relatively unrelated points. The influential Walter Burley (1275 – 1344) is sometimes called an extreme realist. Paul of Venice (1369 – 1429) was formerly classed as a nominalist, but is now considered a realist.

Among those who were called nominalists, there were many different views and distinctions related to the complex medieval theories of sensible and intelligible “species”. In one aspect, these were mental representations, but theories of sensible species usually had a physical component loosely inspired by Stoicism. Occam denied species, while Buridan made use of them.

From the 12th century onward, Latin philosophers developed sophisticated original theories of the different kinds of “supposition”, or generic ways in which something said can be meant. The general notion was that the kind of supposition that should be read into a concrete utterance should be determined by analyzing the context of the utterance in various ways. This was basically a kind of semantics. What is perhaps surprising is that broadly similar supposition theories were largely shared by dedicated nominalists like Occam and commited realists like Walter Burley, providing a common vocabulary.

On a side note, Occam’s causal impact theory seems problematic from the point of view of the development here. While its avoidance of dependence on representation is attractive, a direct causal link from external objects to thoughts does not seem adequate to account for the full range of diversity of thoughts. Also, there seems to be an incipient mentalism already at work here, related to that of Avicenna.

Occam was a theological voluntarist and a fideist. Fideism is the belief that faith offers a kind of knowledge superior to reason, an extreme position that was repeatedly condemned by the Church. Occam has nonetheless often been named as a major precursor of the point of view of modern science. Even though some connections can be made, this seems questionable as well, given his mainly theological intent and the character of the theology he promoted.