In my last post, I suggested that Ockham’s account of language and concepts might be founded on the thesis of a “division of linguistic labour”. In what follows, I would like to say more about this thesis by showing how it figures in the debate over the demonstrability of articles of faith. Far from being a debate of merely theological interest, I believe that the thesis is put to work as founding the idea of a division of epistemic labour, even between the living wayfarers (viatores) and those considered happy in heaven (beati). [If you are mainly interested in Ockham’s account of the division of epistemic labour, you can jump straight to section 2 of this post.]

When Ockham’s pupil Adam Wodeham delivered his Commentary on Peter Lombard’s Sentences around 1330 in Norwich, Ockham had already been excommunicated. But this didn’t stop Wodeham from defending and elaborating Ockham’s doctrines. Like many of his contemporaries, he particularly dealt with questions concerning the relation between theology and the Aristotelian notion of science. One of these questions was whether articles of faith such as ‘God is three and one’ can be scientifically demonstrated. Wodeham’s answer to this question might sound quite peculiar: Instead of a clear ‘yes’ or ‘no’, he replies that it is possible in principle to demonstrate such creditive propositions, but not by means that are available to wayfarers, i.e. human beings in this life. Yet they are demonstrable through sentences formed by one who is blessed in heaven. So, in order for this solution to work, we have to imagine a syllogism that contains the premises of a blessed one in heaven and the conclusion of a wayfarer in this earthly life. In this sense, the epistemic labour is shared even across domains as different as heaven and earth …

Wodeham provides intriguing arguments to defend this thesis, which was originally proposed by Ockham. But what is at stake here? To be sure, it’s one of the big themes: the relation between faith and reason. The question of the demonstrability of creditive propositions aims at the epistemological status of theology. Quoting Augustine, already Peter Lombard warned theologians against endorsing the truths of faith on the grounds of ecclesiastical authorities alone. If theologians do not wish to be utterly defenceless against hair-splitting logicians, they had better come up with some reasonable arguments as well. But how was the gap between natural reason and faith to be bridged? From the mid 13^th century onwards, Aristotle’s Posterior Analytics – a book that clearly did not consider matters of catholic faith – was the leading source on scientific knowledge. If the traditional talk of ‘truths of faith’ is to be taken seriously and that is taken literally, then we require a general answer to the question of what it means for such a ‘truth’ to be true and demonstrable. Yet, if articles of faith were as evident as principles of science, then faith would have to belong to the realm of naturally accessible human knowledge. And since the knowledge of both realms would be equally evident, the difference between the wayfarer’s faith and the beatific vision of a blessed one would be lost. If, however, articles of faith belong to the realm of heavenly knowledge only, then it is incongruous to call theology a science.

I think that Ockham’s solution to this dilemma gave a new meaning to the debate, in the sense that it is rooted in the conviction that knowledge – no matter whether it’s heavenly or earthly – has a general form: it is subject to general criteria of rationality. This form or structure is for Ockham psychologically real in that knowledge is generally given in the structure of a mental language, which means (to a first approximation) that the concepts we have in our minds are structured in ways significantly similar to the sentences we utter. Thus, the difference between a wayfarer (viator) and a blessed one (beatus) is not that they have different types of lower and higher knowledge (or rationality), the difference is simply that they are in different epistemic situations. But for Ockham’s solution to work, it is not enough that there is a common structure of knowledge. We also have to take the different epistemic situations of different knowers into account. Thus, the idea of a common rationality requires a division of epistemic labour. Let’s now look at the debate.

1. Lutterell’s critique

Ockham’s teaching in Oxford and London provoked many criticisms. Already John Lutterell (Chancellor of Oxford University till 1322) was deeply concerned about Ockham’s doctrines: Ockham held that we do not know things but mental sentences whose terms stand for things. Mental terms, in turn, are caused by cognizing things. This doctrine tries to acknowledge the fact that an assent or dissent does not aim at things but at propositions: we don’t say, for instance, ‘the stone is true’, but ‘the mental sentence’, whose subject-term stands for a stone, ‘is true’. To have knowledge, then, is to have a certain mental attitude towards a proposition. Lutterell, however, concluded: “This is dangerous, because it eliminates all real science and faith.” (Libellus contra Ockham, art. 30)

Now since, on Ockham’s account, forming an evident judgement requires epistemic access to the things the proposition refers to, Ockham indeed denied that theology is, strictly speaking, a science and he denied that articles of faith can be demonstrated in this life, although they could be demonstrated in principle by means of premises formed by someone who has epistemic access to God, namely a blessed one. Lutterell, however, won’t have that. One of his main arguments against Ockham’s position is that the blessed would not form a proposition at all. On his account – and in accordance with many medieval theologians resorting to Augustine – the blessed one has a sort of vision which enables him or her to form a single and simple unstructured concept (Libellus contra Ockham, art. 4), whereas humans in this life attain simplicity only in complex ways, that is they do not attain real simplicity at all.

An helpful illustration of the difference between complex and simple thought is the difference between writing a text on your word-processor and looking at the photocopy or pdf of a text: With the word-processor you can alter the text you’re writing, you can copy words or phrases and put them elsewhere and so on; by looking at the photocopy you get the whole text at once, but there’s no way of altering the text or transporting bits of it elsewhere.

Simplicity is a feature of divine perfection and is therefore traditionally held to be a property of the beatific cognition: since, unlike complexity which is often associated with materiality, spatial and temporal order, simplicity precludes falsity or error. Seeing God, then, precludes the formation of complex concepts or any kind of discursive thinking. On Lutterell’s account, the knowledge of the blessed is shaped with regard to the object of knowledge and is thus simple, whereas the wayfarer has to form complex propositions about God, hence reaching the simple only through complex means.

Lutterell’s defence of theology as a science is largely owing to Aquinas, who held that we can justly claim that our complex conclusions about the divine are true, so long as we believe in the principles of the higher and simple knowledge of the blessed ones. But Ockham didn’t buy this argument, maintaining that we cannot know conclusions unless we evidently know the premises.

2. Ockham’s position

Ockham’s own position is quite different. On my reading (see here and here for details), his point is that this way of talking and dividing knowledge is generally ill-formed. So his arguments amount to saying: I grant that these articles of faith aren’t demonstrable in this life, since otherwise they wouldn’t be articles of faith, and there would be no difference between this life and beatific vision. I also grant that we have to construe articles of faith as being demonstrable in principle, since otherwise our faith would aim at nothing. But if we want to say that our sentences could be demonstrable through the premises of the blessed, we first have to grant that our and their knowledge is compatible. And since our knowledge is structured, we had better assume that their knowledge is structured as well, otherwise it wouldn’t be compatible with ours.

But how can Ockham reasonably hold that articles of faith are demonstrable in principle? A scientifically demonstrable conclusion requires that the proposition is (1) necessary, that it is (2) deducible from necessary and evident propositions in a syllogistic discourse and that it is (3) doubtful (otherwise it would be self-evident, and therefore not demonstrable from other propositions). Now, the blessed one can form the required evident propositions, but the trouble is, the blessed one couldn’t form a doubtful proposition, since it would be – presumably – immediately evident to him or her, and thus independent of any argument or any other proposition.

To fulfill the criteria of demonstration it is required that we are in a position to form a doubtful proposition which the blessed one could access in principle. Ockham argues that this requirement is met, if there is someone who can doubt the proposition or if the blessed one was once in a position to doubt the proposition, which in turn requires that the sentence structures are preserved.

As I see it, Ockham’s reply combines two lines of argument: On the one hand, he insists that the structure of thought is the same for all. On the other hand, he argues that the dubitability is provided once there is someone (else) in a position to doubt (see In I Sent, d. 3, q. 4; OTh II, 440-441). It is with this move that Ockham makes the case for a division of epistemic labour. Properties of thought do not have to be fulfilled by every individual thinker. Rather it suffices if someone can fulfil them. In the given case, demonstrability even requires that thinkers are (or have) been in different epistemic situations.

3. Chatton’s critique

Ockham’s idea is, then, that the very same proposition is doubted or believed by the wayfarer and evidently known by the blessed one. So it is possible that someone, let’s call her Martha, reads a theological treatise and stumbles upon the sentence ‘God is three and one’. Martha thinks hard, but neither can she infer this sentence from any principles she knows, nor did she have any experience with any entity that is at once three and one. We may say that she simply entertains the sentence in her mind, without judging its truth or falsity. But then she thinks even harder and realises the overt contradiction in the ascription of something being three and one at once. Now Martha, not familiar with the many logical twists and turns of trinitarian debates, concludes that it may be impossible for something to be three and one at once and doubts the sentence. Now, she may have a conversation with the author of the theological treatise in question and find him rather learned and trustworthy, so that she eventually casts aside her doubts and believes that after all there might be one entity that is very special just because it is beyond contradictions in terms. We might say then that she believes the sentence on certain premises. Now, let’s assume that Martha dies and is entitled to beatific vision. She might then, as it were, remember the sentence and evidently judge that it is necessarily true.

Although one might argue that this judgement is not a demonstration, because the kind of sentences she can form on the grounds of immediate experience are self-evident and not dubitable, we can reply with Ockham that it is indeed a demonstration because the blessed one’s newly acquired sentences are the very premises from which she infers the truth of the very sentence she formerly believed. Sentences and its parts are transportable. They can recur in different contexts, even in heaven. But Ockham pushes the point even further: it is sufficient that someone can doubt the proposition in question. Presumably, the blessed ones cannot doubt articles of faith. Therefore, it is vital that some wayfarers in this life have doubts, and thus enable the division of epistemic labour.

On Lutterell’s account, this cannot be true, because the blessed one doesn’t entertain propositions in his or her mind, so the parts of former propositions could not be transported into the newly formed simple cognition. But Ockham encountered smarter opponents than Lutterell. To be sure, it’s perfectly possible to grant that the blessed one can think discursively, and still deny that wayfarer and blessed one can entertain the very same propositions.

Ockham’s opponent and fellow Franciscan Walter Chatton attacked his doctrines in many respects. Chatton granted that the blessed ones can think discursively, but he still denied that articles of faith can be demonstrated, on the grounds that such an article cannot be the conclusion of a heavenly demonstration. In this life we have premises from which we might infer a sentence and believe it; in heaven we have other premises from which we might infer a similar sentence, but – says Chatton – although our common manner of speaking might suggest that we are dealing with the same sentence, we have in fact sentences of a different kind. Because different kinds of premises acquired under different epistemic conditions entail different kinds of conclusions. And the blessed one could not but immediately judge that the wayfarer’s sentence is true. So Chatton infers that, although the knowledge of the wayfarer and the blessed one might be discursively structured, it still is of different kinds and thus incompatible.

4. Ockham’s reply and Wodeham’s defence
   

Ockham concedes that the wayfarer’s premises are different from the premises available to the blessed one, but he denies that Chatton’s inference, according to which ‘different kinds of premises entail different kinds of conclusions’ is valid. As Aristotle had already established in his Posterior Analytics, the knowledge of the conclusion is not necessarily caused through the knowledge of the premises. Accordingly, Ockham claims that the blessed one might have the conclusion before he or she turns to assess the premises in order to prove the conclusion. And this conclusion may well be the article of faith that the now blessed one formerly entertained as a wayfarer in this life under insufficient epistemic conditions.

As I have said in the beginning, Ockham’s pupil Adam Wodeham defended this position. He counters Chatton’s tenets by pointing out that it does not contradict the beatific state of the blessed one if he or she forms the sentence of a wayfarer. This was exactly the idea that Chatton meant to attack, when he claimed that the article of faith of a wayfarer could by no means function as the conclusion of a demonstration, otherwise – Chatton had argued – we couldn’t say that the blessed one has more evident knowledge than the wayfarer.

Wodeham’s move against Chatton is even more subtle than Ockham’s initial defence. Wodeham repeats Chatton’s thesis that “the blessed one could not but immediately judge that the wayfarer’s sentence is true” and asks how the blessed one could achieve this judgement without engaging in a syllogistic discourse. Wodeham then explains that, if the blessed one assesses the sentence of the wayfarer, the blessed one has to demonstrate not his own but the wayfarers’ conclusion. Wodeham thus points to the logical blunder committed by Chatton: If the blessed one had solely knowledge of a different type, incompatible with the wayfarer’s knowledge, then the blessed one couldn’t know whether the wayfarer’s sentence is true. According to Wodeham, Chatton missed his target and refuted himself.

5. Conclusion

Ockham and Wodeham argued against their opponents that the degree of certainty of knowledge and belief depends on the epistemic conditions of the knower. The difference between the knowledge of a wayfarer and of a blessed one is not a difference between types of knowledge but a difference of epistemic situations: If, for instance, I actually see something, I can form a reliable judgement about its existence and the properties belonging to the object seen. If I see God, then I can claim to have evident knowledge about him; in this life however, the sentences I form are expressions of faith. There is thus no difference with regard to the type of rationality, such as the difference between simple intuitions and complex propositions. All knowledge is processed in mental sentences which have a compositional structure and transportable parts.

Ockham’s point was not to raise hopes that we might meet the odd blessed one and ask him or her to demonstrate our conclusions. His thought experiment was designed to show that we need to assume a generally consistent structure of knowledge, if we want to claim compatible criteria for identifying and assessing judgements formed under different epistemic conditions. The scope of rationality that Ockham assumes comprises the knowledge of all thinking creatures, including humans, blessed ones and angels, creatures whose knowledge is shaped by common structures, rendering knowledge identifiable under different epistemic conditions. But for the idea of a common rationality to work, there also needs to be a division of epistemic labour. In this sense, Ockham defends a social notion of rationality.

6. An afterthought

Ockham’s and particularly Wodeham’s subtle defence against those who assumed a plurality of incompatible types of lower and higher knowledge rest on interesting arguments. But as in many construals of logical form as not merely an instrument but the actual shape of knowledge itself, there remain troubling questions, one of which I’d like to sketch now at the end of this post: Do not many of these defences amount to transcendental arguments by means of which we proceed from supposed facts to the necessary conditions of their possibility? I think we are indeed inclined to infer from the fact that our reasonings are logically reconstructible, that it is a necessary condition of the possibility of such a reconstruction that the logical form really is a feature of our knowledge. Recall: Wodeham claimed that, for the blessed one to assess the wayfarer’s sentence, he or she needs to entertain and demonstrate the wayfarer’s sentence, and that hence their shapes of rationality have to be compatible. That seems quite conclusive.

If I assess a sentence S, the necessary condition of the possibility of my assessing S is obviously that I can form and entertain S, and thus that my mental capacities and structures have to be of a kind allowing for the entertainment of S. We couldn’t even talk about the blessed one doing so without implicitly or explicitly ascribing to him or her that capacity.

The trouble with such arguments is that our ascription of such capacities can be both indispensable and false, false at least in the sense that the capacity of entertaining S might completely exhaust the blessed one’s structured rationality, and that every other piece of his knowledge is indeed couched in a different, namely structureless type of rationality. On a lighter note we might urge this point as follows: When you have finished reading this post and you’ll start forming critical responses in your mind, you’ll certainly do so on the assumption that I have written this post in English and that we share a common rationality. You’ll say: the fact that Martin has written this post and might even respond to my comments rests on the condition that he has the capacity to speak English. But maybe I have just shot my bolt and wouldn’t know how to write anything else that might look like English; perhaps this post is just a sort of gap in my otherwise entirely different way of thinking. To put it in terms of the illustration I gave in the beginning: I might not be processing words, but simply be tossing out a sort of photocopy. So if I can’t reply to your comments the reason may well be that I didn’t write this post in English in the first place. The letters I have written down here may just look very similar to English words. But then again: how could I tell you that without sharing or anticipating your assumptions?

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*This blog post is the revised version of an unpublished paper, first presented at the conference Dialectic on Trial, Cambridge, Clare Hall, 2005, and it contains some passages from my papers published here and here.

 

One fascinating feature of language is that it enables us to talk about and thus handle things that we have no clue about. Although I have never seen a dinosaur, I can talk about dinosaurs and even recognise images of them. Arguably, this feature of language is owing to what Putnam called the “division of linguistic labour”. Although I don’t know anything about or at least not much about certain things, I can apply the words correctly. The reason I can do so is that I defer to other speakers, in this case experts who do have the knowledge I lack. According to this view, language is not a solitary tool like a hammer, but a social tool, only working in a collective, like a steamship. Although the social understanding of language is often portrayed as a modern idea, I’d like to suggest that it dates back at least to the early 14^th century.

Thinking about language in wake of Putnam, we might find the thesis of the division of linguistic labour quite intuitive. But it doesn’t come naturally if we follow the standard interpretation of what is now known as the semantic triangle as sketched in Aristotle’s Peri hermenias (16a3-9). Here, Aristotle suggests that words relate to things in virtue of the mental concepts we have of things. The reason that words like “apple”, “pomum” or “Apfel” signify the same things is that they signify the same non-linguistic concepts. A common way to take this mediation of the word-thing relation through concepts is to assume that speakers must know the things they refer to. Using the word “apple”, then, requires me to have the concept of apple and thus knowledge of apples. – Now, in the first chapter of his Summa logicae, Ockham rejects this assumption. As is often the case, he frames his rejection as the proper interpretation of Aristotle. The details are a bit technical, but his own view is clear enough. In the translation by Paul Spade (p. 5-6), Ockham argues as follows:

Now I say that utterances are signs subordinated to concepts …, not because, taking the word ‘signs’ in a proper sense, these utterances always signify those concepts of the soul primarily and properly, but rather because utterances are imposed to signify the same things that are signified by the concepts of the mind, so that the concept primarily signifies something naturally, and the utterance secondarily signifies the same thing, to such an extent that once an utterance is instituted to signify something signified by a concept in the mind, if that concept were to change its significate, the utterance itself would by that fact, without any new institution, change its significate. The Philosopher says as much when he says that utterances are “the marks of the passions that are in the soul”. Boethius too means the same thing when he says that utterances “signify” concepts.

According to Ockham, then, words (translated as “utterances”) don’t signify things by signifying concepts first; rather it is enough that words signify the same things that are signified by the concepts that the words are subordinated to. Let’s compare these views schematically (the arrow indicates a signification relation):

Aristotle:            word     –>         concept  –>     thing

Ockham:            concept –>       thing

                            word      –>         “

So while the Aristotelian model suggests that each successful use of a word requires the user to have a concept that is signified by the word, Ockham’s model only requires that the word be subordinated to a concept. It is neither required that every actual use is mediated by a concept, nor is it required that the actual user does have the concept in question. Arguably, it is enough if some users have such a concept. If this is correct, we can assume that even those users who don’t have the pertinent concepts can use words correctly.

Although Ockham does not develop this idea straightforwardly into a thesis of division of linguistic labour, his rejection of the standard Aristotelian model clearly opens the door to such a view. Although she does not ascribe such a division thesis to Ockham, Sonja Schierbaum’s discussion of Ockham provides further evidence for such a reading. Ockham doesn’t develop this subordination semantics out of the blue. The discussion about the naming of God already led others before him to acknowledge that the use of words allows for talk about things that we don’t understand or have concepts of. (See here for more on this issue.) What Ockham adds in the Summa logicae is the idea that words can generally be used for referring to things irrespective of our concepts or knowledge. All that we need is that some other users have those concepts.

The upshot is (1) that conventional language is a more powerful tool than the mental concepts to which conventional language is subordinated and (2) that individual language use requires other users, especially for cases in which we lack pertinent concepts or knowledge.