300b. The Relevance of Medieval Philosophy Today

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Peter King, Catarina Dutilh Novaes, and Russ Friedman discuss their approaches to medieval philosophy and its contemporary relevance.

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Further Reading

Websites for our three guests, with lists of their publications:

Peter King

Catarina Dutilh Novaes

Russell Friedman

Comments

Robert Jackson on 12 May 2018

Thank you - with observation #1

Peter, thank you for your hard work over all the preceeding years in putting together and making this podcast.  It has helped me immensely as I study philosophy (and I now also teach it).   I retired from law about 4 years ago and have studied philosophy or philosophy related issues for about 40 hours per week since then ( I count listening to your podcast as part of that effort).  I am grateful for all the insights you have provided and any comment I make should be interpreted in light of that context.  My primary confusion after listening to your two 300th podcasts was the lack of clarity as to why one should study the history of philosophy.  Perhaps I am confused, but I see a very clear reason for this study and it is invaluable (in my opinion).   In answering the question as to why study the history of philosophy than say reading Tom Clancy or Charles Dickens or watching TV,  the answer I got was that it might help some modern philsophers in their academic work or one or another of an esoteric issue.   I must have misunderstood.   My own view is closer to Hegel's (whom I detest) than to what I understood you to be presenting.   Can you explain why you think it is worthwhile to study the history of philosophy (other than it is interesting and fun, which is also my opinion!).   Again, thanks.   And, on Hegel, I concur with the late Stanley Rosen in his comment on Hegel's "Science of Logic" that Hegel made egregious errors.   

 

In reply to by Robert Jackson

Peter Adamson on 13 May 2018

Why do this at all?

Actually one thing I liked about the 300 interviews is that we got a range of different answers to your question; and in fact I myself think there are more than one good answer. My own view is probably closest to Russ Friedman's, namely that the history of philosophy is often salutary because it shows us ideas and concerns that are _different_ from those of contemporary philosophy. (Cf. the beginning of the old episode on Averroes on the mind.) However I also just tend to think that the history of philosophy is interesting and valuable in its own right; compare the study of plain old history. You can justify that by saying that ignorance of history makes it harder to decide what to do now - repeating the mistakes of the past etc - but really I think the main reason people are interested in history is that history is intrinsically fascinating, and the same goes for history of philosophy. The reason I had the 300 interviews focus on the contemporary relevance question is actually that I have hardly ever talked about this in the podcast, which shows you how far I am from thinking that contemporary relevance is the sole motivation. But I do think it is one possible, even important, motivation among others.

Robert Jackson on 12 May 2018

Comment on Ms. Novaes' Geneology

I am not at all familiar with Nietzche.  But i found Ms. Novaes' comment on "Geneology" interesting.    You compared it to Nietzche's use of the same in describing morals.   Might I suggest you refer to the Naya (I may have the name wrong) question structure (which I really like):  (a) truth seeking, (b) argumentative (I call it "law argument"), and (c) skeptical.    In (a), the truth is the goal; in (b), the goal is to win and the "truth" is whateve makes the best story (without regard to what is the truth), and (c) focuses on a type of argument which destroys your opponents position, but, if used on your position would have the same result.   I think the Naya were correct that the "argument (or dialectical) structure" determines the quality and type of outcome.   In the second two, one gets the truth usually by accident than design.   Using this model,  Ms. Novaes' "Geneology" is modeled on a "truth seeking" structure, while it seemed that Nietzche's was either argumentative or more likely skeptical.    

Steve Balch on 31 May 2018

idea for future podcasts

Dear Professor Adamson:

I'm an enthusiastic auditor of your podcast, taking in on average two per day. (I'm glad I started about four years after you began. No need to sit impatiently waiting for each new intsallment.) Congratualtions, it's quite a tour de force. 

I run an Institute at Texas Tech University devoted to the Study of Western Civilization. But I've long realized that you can't understand one civilization without knowing a good deal about the others. You're already providing great services in that respect.

But wouldn't it be better still  if you could devote a few casts (or would it be pods) to explicit, systematic comparisons of Latin and Islamic scholasticism with respect to things like topical emphasis, treatment of common questions, breaadth of opinion, nature of sources, institutional anchorage, relationship to religious orthodoxy and authority, permissible latitude, etc.? One develops impressions about these matters simply from following your lectures, but nothing could compare with a treatment from the hands (or voice) of the master - yourself. You might also eventually do the same with respect to the Byzantines, Indians and, if you ever get there, the Chinese, though the Latin and Arabs are the natural  starting place given your expertise and the fact that both traditions branch from the same Greek trunk.

You've done so much already, but before getting to the moderns why not this more?

In reply to by Steve Balch

Peter Adamson on 31 May 2018

Cross cultural comparison

Thanks for your enthusiasm about the project! That's an interesting idea and in fact one I am kind of pursuing in other efforts, so for instance I am hoping to write a book for the general reader in the next year or two on attitudes towards authority in late antiquity and all three medieval traditions. I am not sure how this sort of cross-cultural comparison would fit into the podcast series but it could be an idea for a special episode, since I always have those at 50 episode marks. So, maybe a thought for episode 350?
 

Nursen Topal on 29 June 2019

medival period and women

Dear Mr Adamson,

I couldn't find anything from you about Teresa de Avila. That is a pity, because I would have loved to hear your aproach to her writings. Thanks for the great potcast and the even better lectures at LMU. I hope, you will continue to release videos from the lectures. They are really helpful.

Best regards,

N.Topal

In reply to by Nursen Topal

Peter Adamson on 29 June 2019

Teresa of Avila

Don't worry, we are getting to her! She's 16th century so she will be covered when I am looking at the Reformation and Counterreformation. In fact she's already on my rather sketchy list of figures and topics to cover.

Otter Bob on 29 June 2019

Videos?

Videos from your lectures at LMU?  Where does one find those--YouTube?

In reply to by Otter Bob

Peter Adamson on 29 June 2019

Videos

On YouTube you can see me giving a series of ten lectures on women in ancient and medieval philosophy, in English. The LMU does have some lectures from my classes up in German too. You can marvel at my cavalier attitude towards the gender of nouns.

tachyon on 10 September 2020

Philosophy of Language is dead?

Dear Dr Adamson,

First of all, of course, thank you for this marvellous and fascinating series. Over the years i have been listening i have gone from knowing nothing whatsoever about the history of philosophy to becoming an enthusiastic reader, all thanks to your work.

I was intrigued, and maybe even a bit alarmed, by Peter King's remark around 1:46 that philosophy of language is dead (still moves, still walks, but it's dead). What do you suppose he meant by this? Has the return to metaphysics killed off the linguistic turn? Is the philosophy of language only a matter of historical interest at this point?

In reply to by tachyon

Peter Adamson on 10 September 2020

Philosophy of language

Thanks, glad you like the series and that it has led you to dive into the texts!

I'd forgotten that throwaway remark, and to be honest I am not sure when he meant but your guess is a good one, i.e. that he means the mid-20th century approach where all philosophical problems are reduced to linguistic questions is pretty out of fashion. But of course plenty of people still do philosophy of language without trying to reduce all problems to linguistic ones.
 

 

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Transcript +

Note: this transcription was produced by automatic voice recognition software. It has been corrected by hand, but may still contain errors. We are very grateful to Tim Wittenborg for his production of the automated transcripts and for the efforts of a team of volunteer listeners who corrected the texts.

Peter Adamson: Hi, I'm Peter Adamson and you're listening to the History of Philosophy podcast, brought to you with the support of the Philosophy Department at King's College London and the LMU in Munich, online at HistoryofPhilosophy.net. This will be a second installment of our special 300th episode, looking at the contemporary relevance of all the philosophy we've covered on the podcast so far. Today we'll be talking about the relationship between medieval philosophy and philosophy today, starting with Peter King, who is professor of philosophy and professor of medieval studies at the University of Toronto. So, we're going to be talking about the relevance of some of your work on medieval philosophy to issues that philosophers care about today. Maybe you could first, though, tell us whether that's actually something you're interested in. I mean, did you get into medieval philosophy because you wanted to expose its relevance for modern-day philosophical debates?

Peter King: Well, like many people, or at least those who are honest will tell you, I got into medieval philosophy completely by mistake, or by accident, I suppose, to keep that Austinian distinction. I began working on philosophy of mathematics. My undergraduate degree is in mathematics. And so I started to work on philosophy of mathematics, and that led me to, more broadly, philosophy of language. That was about the time philosophy of language was declared dead. Currently it's a zombie. Still walks, still moves, but it's dead. And so I thought, well, I suppose I ought to really learn something about how we got to this point. That led me to history. Then I thought, well, I should really learn something about the history they're not teaching me a lot of, and that led me to read things. And eventually I wound up in the Middle Ages, and here I am today.

Peter Adamson: And you just magically learned Latin along the way, some there.

Peter King: It wasn't magic. It was hard work, but I learned Latin along the way.

Peter Adamson: Okay. And do you, in fact, think that there are areas of medieval philosophy that are particularly relevant from the perspective of a contemporary philosopher?

Peter King: There are lots of them. Just to name two or three: one is, for example, what Wilfred Sellers once said, to remind you of what Wilfred Sellers once said, which was that the Middle Ages was when logic like knighthood was in flower, for example. Metaphysics, if now that metaphysics is no longer a dirty word, and we do metaphysics these days, that's the golden era of metaphysics, of course, back then. There are obvious connections with things like philosophy of religion, and less obvious but important connections in, for example, the history of ethics, the shift away from virtue ethics to will-based theories of ethics and so on. What I mostly work on these days is the history of the philosophy of psychology. Philosophy of psychology, of course, especially in its guise of cognitive science, is very important to contemporary philosophers these days, and I think there's a fair amount in the Middle Ages that is quite similar and that each can shed some light on the other.

Peter Adamson: That seems like a kind of surprising choice, actually, because if you look back at medieval theories of the soul, they obviously believe that the soul is a substance in its own right, it's immaterial, can survive without the body, whereas most contemporary philosophers of mind are inclined towards rather physicalist accounts of the mind. So naively, someone might think that actually if there's any area of medieval philosophy that's not going to speak in a useful way to our concerns today, it would be precisely the theory of soul.

Peter King: Yeah, well, you understand that they, following a certain line of interpretation of Aristotle, thought that psychology included things such as animal behavior, animal perception, animal reaction and so on and so forth, and they thought that was continuous with us. A large chunk of psychology works on animals, which they thought were certainly had only embodied souls, material souls and so on. There were also several philosophers, even in the Middle Ages, who thought that philosophical reasoning in the absence of revelation, setting revelation aside, would lead one simply to conclude that the human soul was in fact a material perishable form. William of Ockham thought this, but was a bit coy about it. It's very clear in somebody like Jean Buridan, who actually identifies six or seven characteristics and says either they all go together and you get a separated immaterial non-personal soul, like certain Arabs may have thought, or their opposites go together and you get a perishable individual material human soul. Those are the only things philosophy could accept. You either get the whole set or it's negation.

Peter Adamson: Because it all comes together.

Peter King: Right. And then what revelation does is tell us that in fact, what is a logically impossible mixture of these theses holds.

Peter Adamson: So someone like Buridan would actually say that the contemporary philosophers of mind are right because reason would actually lead you to think that the human soul is like the soul of an animal in being eminent in the animal body. And because contemporary philosophers of mind don't usually draw on revelation when they're doing philosophy of mind, they would have reached the right conclusion actually.

Peter King: Very much so. He would approve of them entirely. Now mind you, not all contemporary philosophers of mind are materialists. They're those who think that the hard problem are things like the problem of consciousness, the problem of phenomenality and so on. Philosophers like David Chalmers are known for thinking that that's the really hard question. They often think that these are the sorts of considerations that impel one to think that at least some parts of the mind are non-material. And of course, the argument given by various philosophers in the Middle Ages were that it's in virtue of certain kinds of abilities or features of our thinking that we have to concede that the mind is non-material. Right. Now they tended to identify different features. They identified our ability to think abstractly or generally or universally as reason to think that our minds are therefore not material. But many of the same sorts of considerations hold and apply.

Peter Adamson: And they obviously have to explain the cognitive faculties that we have to explain. I mean, they have sensations, so do we. They have imagination, so do we. They have capacity for abstract thought and so do we.

Peter King: Absolutely. They stepped on stones and it hurt. But the way they do it is there's more parallels than simply having to explain the same phenomena because they came to want to try to explain the same phenomena in something like the same ways. So let me explain what I mean. When the texts of Aristotle were translated into Latin along with commentaries from both Greek and Arabic sources, there was a challenge to try to understand how psychology could be a science in the proper sense of a science that Aristotle had endorsed in the posterior analytics. And what eventually they came to devise was a system for thinking about the mind that was based on Aristotle but had a special character which is rather like the character we sometimes impute to psychological theories today. We call it now dismissively the medieval version. We call dismissively faculty psychology, but there's more to it than that. The basic idea is that to explain psychological phenomena, you postulate certain kinds of sub-personal centers of activity within the soul. I'm just speaking of the soul broadly here. This could be the level of sensation or the level of thought. And these centers of activity exchange information back and forth. And so you try to explain psychological phenomena as an emergent property of the lower level interaction of these faculties.

Peter Adamson: An example of this would be like I look at a giraffe. I get a visual image of the giraffe in my sensitive faculty and then it maybe stores that information in my memory which is another faculty. I can use my imagination to call up an image of a giraffe and play around with it, et cetera.

Peter King: Right. Now they explained how it's the image of a giraffe that's present both outside and in your sense organ and then in your sense faculty, then in your various psychological faculties such as imagination and so on and so forth. They explained that by saying there was an identity of form - that one receives the form of the giraffe without the matter and then that form can be located in various different parts in psychology. So it's the same form. Well if you take the Greek word that's an isomorphism. It is, right?

Peter Adamson: Because morphe means form in Greek.

Peter King: And what you get then is a view that says that you have the same form, you have an isomorphism between these various faculties in virtue of sharing essentially the same kind of information which can show up in different faculties in different ways. It can be a configuration of rod and cone firings in the eye, in the sense organ when you see the giraffe. It can be the particular representation of the giraffe that's stored in your sensitive imagination. It can be the cognition of the giraffe when you think about the giraffe. It can be the object of the will when you are filled with an upsurge of admiration and longing to own your own giraffe, et cetera, et cetera, et cetera.

Peter Adamson: And is that what contemporary philosophers would call content, like the content of a cognitive act?

Peter King: Close enough for the most part. Close enough for the most part. The actually... It's a bit more complicated than that because in order to get the content of a cognitive act you have to have a strong act content distinction and that takes some time to evolve in the history of philosophy. I blame this on Duns Scotus myself which means around the start of the 14th century.

Peter Adamson: Yeah, that's what I was thinking is that it comes in the 14th century. And so if you have, for example, mental acts in Occam which are linguistically structured it's pretty easy to think about that in terms of content, isn't it?

Peter King: Yes. And indeed, presumably that's one of the reasons he went to endorse the idea that mental language is the language of thought. It allows you to talk about thought in a contentful way that is intuitive and doesn't need any fancy explanation. It's essentially linguistic.

Peter Adamson: And maybe it makes it easier to think about how the different faculties talk to each other as well because it's the same kind of content.

Peter King: Well, Occam didn't think we needed different faculties. He radically simplifies psychology. Let me tell you what psychology looked like before he simplified it. So it had the same sort of picture where you have different faculties which would interchange information. So your sense organs would take in information, i.e. the form of things outside, then the sense faculties in question would pass that information along for storage and memory and pass it both up and over. It would pass it over to sensitive appetite. So you would have what we would call an emotional response or you could have an emotional response to things, either fear or longing or what you will, or could pass it up. In the case of humans so we could think about the things and having thought about them, we could then exercise choices and make decisions with respect to the things in question. So I could look over and see not a giraffe perhaps, but a lion. That would involve a certain kind of representation or information in my sense organ sense faculty. That would trigger a response which would be a response of fear. This can be hardwired or wetwired in animals - it is so that a certain kind of literal configuration of the brain causes a fight or flight response. And then it can go up in humans to the case of being a thought of a lion, but I could then for example also have the thought, aha, this is a tame lion, this is a domesticated lion. I don't have to run away. I can overcome my impulse to run away that's in my sensitive appetite and with my intellect of appetite I could choose to stand my ground knowing that - believing at any rate, that this lion will not harm me. So what happens is that sort of the lion or what it is to be the lion gets passed around among these various faculties through a series of causal interchanges and results in some sets of overt psychological behavior and perhaps even just overt behavior. Now the idea that you can explain psychology and perhaps overt behavior by talking about the interchange of information among faculties is very similar to what many people have tried to do with modern cognitive science. They tend to think that faculties isn't the right way to do it, to think in terms of the modularity of mind by which they think that we want to explain psychological phenomena in terms of very specific modules that carry out specific tasks rather than being responsible for a wide range of phenomena under the task. But the basic idea is that you try to do psychology by having a working model of the interactions among the constituent parts and the theory is as good and powerful as an articulation of the constituent parts allows you to explain in more fine-grained detail how things come to be and how they come to pass in the mind.

Peter Adamson: And maybe it's worth mentioning that the medievals would even have thought that these different powers or maybe it was called modules are seated in the brain and they claim that they could locate in the brain where the memory was and the imagination and so on.

Peter King: Most of them are very, very highly localizable and there are those philosophers who thought that all of them seemed to be localizable such that reason would drive us to think that the soul was simply material.

Peter Adamson: Right, as you mentioned before. So you're saying that Occam resists this way of thinking about the soul and tries to simplify everything. So rather than thinking about kind of discrete faculties, he has a more unified theory of soul?

Peter King: Yes, this is a somewhat heterodox view of Occam, but Occam thinks that, well, Occam's basic idea is to think that philosophers at least can dispense with details of causal processes. So it's an axiom that he enunciates in his Repertatio lectures that, given an agent and patient in sufficient proximity, an effect will follow. It's just that's what it is for an agent and patient to be in sufficient proximity that in effect follows. Now he doesn't want to give any kind of explanation or discussion of how that works. Right? So he can give up the complicated causal explanations by which philosophers/natural scientists tried to explain how external things can affect the intervening medium by transmission of information that's then brought in and processed in bodily ways. Occam just wanted to leapfrog over all that and say, doesn't matter. So long as there's a giraffe there, then Peter Adamson will have a seeing of the giraffe experience and we don't have to give further detail or explanation. That's all we need. So he got rid of most of the subordinate faculties and even got as far as he could to get rid of the distinction between, for example, thinking and feeling or intellect and will, as we would call it. He said that's merely conceptual. It's all in the way you look at it.

Peter Adamson: It seems like that should be connected to something you were saying before, namely that it all comes together, because if you just basically have the soul with its dispositions to react to things in certain ways, then it's hard to believe that it could sort of cleave in half and part of it is embedded in your body and the other half can happily go its merry way when your body dies.

Peter King: Indeed. It answers a problem that people who've tried to disassemble the mind into component constituent interacting bits have always to face, which is what makes this one mind, right? Where's the unity come from? So Occam does this radical simplification. Then he explains how certain psychological events take place by talking about what he calls, well, the Latin word is habitus, which are skills or abilities. We acquire these by interacting with the world. Then he thinks we can talk about thought in a language-like way and that's all. We can stop at that point, right? We don't need to give complex causal accounts of exactly how information gets from the intellective part of the brain over to the sensitive part of the brain and so on and so forth. So Occam's a bit odd in that he thinks that you can make psychology much simpler. Now the rejoinder to Occam was that he got rid of the very things that gave the theory explanatory purchase, right? Sort of the meat and potatoes of this kind of almost functionalist attitude towards the mind are to be found in its ability to identify smaller parts, which you can then utilize in various explanations for various things. That project is, in general the project, as I said, modern cognitive science, although the Medievals take it much more broadly to incorporate not just cognitive but also affective psychological phenomena as well.

Peter Adamson: Can I go back to something you said before when you were first talking about faculty psychology? You said that these different faculties interact with one another, which makes it sound like mental life as such emerges from the interaction between the faculties. So now sticking with the more traditional faculty psychology, would it be fair to say that they were trying to explain something like consciousness or mental life, or are they just trying to explain sort of episodic examples of sensory experience thinking and so on?

Peter King: They were trying to explain all of the above. So the accounts certainly explain what's going on when you, for instance, first encounter a giraffe and acquire the concept of giraffe and think about giraffehood and so on and so forth. So they're very good at explaining that. Consciousness was usually, well, it was a subject of great debate as it is today. So some people thought that consciousness is simply a matter of having certain kind of what they called reflexive or second order acts, that is to say thinking about thinking, where thinking itself can be the object of acts themselves. And there was a lively debate which tended to go roughly along the lines of religious orders, the Franciscans versus the Dominicans and so on. But however people lined up on the sides, there was a lively debate about whether, for example, we had a direct experience of our own selves or not, whether we inferred ourselves from our direct experience of representatings and acts of memory and choosing or whether we somehow had a direct experience of ourself as being the subject that's doing all these things and so on. So these were all questions like today. We still don't know very much about these things. These are all questions that were very much on the table and debated particularly from about the 1270s to the 1320s and so on. And various philosophers took various positions on these and thought, oh, well, you can explain this this way. And others thought, oh, no, that's really quite silly. You have to do it another way and so on.

Peter Adamson: Okay, so maybe just to wrap this up, then I'll ask you the big question, which is now that you've shown us that there was this very rich psychological theory or actually more than one theory in the medieval period and that they seem to have been trying to answer some of the same questions that philosophers of mind answer today and even giving answers that look similar. What should we take from that? I mean, would you say, hey, philosophers of mind, you might want to go read this because it may give you ideas... or what do you think is the actual usefulness of noticing this resonance between the medieval debate and the current debate? Is it just kind of interesting for antiquarian reasons?

Peter King: No, it's not just antiquarian. It's not just anachronistic either. But these are a set of things, puzzles that we still don't know sensibly how to think about. That's sort of the bottom line. We know scientific investigation of human cognition and affective phenomena has come a bit of a way, but it's still very, very much in its infancy. We don't really know how to think about a lot of it. And so these are topics and issues and questions that are very much open. And a lot of the framework we use is inherited from the Middle Ages. To take one example, the notion that we have nowadays of the will as being a faculty of choice and decision. We think that's important and so on. That's very much a medieval notion that was sort of forged during the Middle Ages and we take it from there. Can modern people who do philosophy of mind learn a lot from reading the medievals on the subject? Yes, they could because there is, like I say, a great deal of speculation and interesting suggestions on the topic, for example, about whether consciousness is simply a matter of having a higher order mental representation, which is a medieval thesis held by some, which is very much parallel to the sort of cognitivist account of consciousness that somebody like a contemporary philosopher like Dan Dennett gives of consciousness. So it's not merely antiquarian because there are enough points of contact on enough open questions so that they have quite interesting and distinct things to say that we might well profit from by reading. If we take a richly articulated medieval apparatus and add to it scientific research, we might actually come near, dare we say it, the truth about these things.

Peter Adamson: Okay, that's great and a very optimistic way of looking at it. So thanks very much to Peter King for coming on the show.

---

Peter Adamson: Well, our next guest will be Catarina Dutilh Novaes, who is professor of philosophy at the University of Groningen. Hi, Katarina. Thanks for coming on again. We had you on before to talk about medieval logic. And though you do work on medieval logic and have published a lot in this area, you also work on kind of logic, logic. And this I thought...

Catarina Dutilh Novaes: Or mostly philosophy of logic, right?

Peter Adamson: Yeah, as far as I'm concerned, that's logic. I just mean non-historical logic. And so I thought you'd be a perfect person to ask about the topic of this episode, which is basically what does the study of the history of philosophy have to do with contemporary philosophy? Maybe we can start by talking about what a contemporary philosopher can learn from the history of philosophy. And we could perhaps just talk about logic in this case. What can someone who's interested in the philosophy of logic learn from studying medieval logic?

Catarina Dutilh Novaes: Right. So perhaps it's easier if I start with a fairly concrete example. So one of the main concepts that have been discussed in philosophy of logic of the last perhaps 20, 30 years is the concept of logical consequence. So that's become a very central concept starting with a book published by John Etchemendy in 1990, so called the Concept of Logical Consequence. It really reignited the debates. And so philosophers of logic have discussed a lot about properties of... So Etchemendy had said that one of his main points was that the Tarskian notion of logical consequence, which it was a formal account, didn't really capture what he claimed was the intuitive notion of logical consequence. But he didn't really say much about what this intuitive notion would have been. And so there's been a lot of debate on this in the last three decades by now. But then if you want to understand what the so-called intuitive notion of logical consequence is, what is that? What kind of concept are we dealing with? So consequence normally is understood as the relation between premises and conclusion in a valid argument. And you can spell this out particularly in terms of deductive validity, so that the premises necessitate the truth of the conclusion. So of course you can also have inductive arguments, abductive arguments, which don't have this property of necessary truth preservation. But in the case of these discussions of philosophy of logic, it's really about consequence understood as having the property of necessary truth preservation. Is that clear what I mean by that?

Peter Adamson: Yeah. So all that means is that if you have the premises, if the premises are true, then necessarily the conclusion is true.

Catarina Dutilh Novaes: Exactly. So this relation between certain premises and certain conclusions, that's the object to, it's been the object of analysis of philosophers of logic. And they've been trying to understand what that is. And there's been a lot of going back and forth. And at some point it kind of reached rock bottom. You're like, okay, so how are we going to come to grips with what this so-called intuitive notion is? And here's where I think history can really be very instrumental. And so a lot of my work has been on trying to unearth the historical origins of this so-called intuitive notion of logical consequence. So in Tarski's seminal paper called The Notion of Logical Consequence, he formulates two conditions of adequacy, which are informal conditions of adequacy, which he then says any formal account of logical consequence has to do justice to these two conceptions. And one of them is a necessary truth preservation criteria. And the other is what he calls a formality criteria, right? That any substitution of the non-logical terminology in that particular scheme would also give you arguments that are valid, right? That would also maintain the validity of the consequence relations.

Peter Adamson: So if you have like, if A, then B, and A, then B follows and it doesn't matter what you put in for A, B, or A.

Catarina Dutilh Novaes: And you can do design with either propositions or with terms. You can also say like, take a classical syllogism, always B, always B is C, therefore always C. It's also a schema that has these placeholders there and then whatever you put in there will give you a valid argument. And so he states these as kind of the, he claims they are the everyday notion of consequence, which of course is very strange because this idea of necessary truth preservation is not something that's intuitive to people who are not trained in logic. In fact, anyone who has ever taught introduction to logic knows that it's really hard for students to understand that there can be no exceptions whatsoever, right? So whenever the premises are true, the conclusion has to be true. So this notion, right, this is kind of like, you know, Tarski presents as a kind of like a thing that exists in and of itself. But I really thought, but we need to understand where this is coming from. And so then in this situation, it's really useful to then come to grips with the so-called intuitive notion that we're trying to capture with our formal systems. And one way in which you can do this, at least one way that I even find indispensable is to go back in history and see what are the historical origins of this notion. And so a lot of the work that I've done on the notion of consequence has been to unearth the history of the, you know, why we came to think of consequence in this way. And I call this exercise at unearthing the origin "conceptual genealogy," right? And so I'm interested in how over time, uh, there have been several concepts of consequence that have been, uh, you know, entertained, formulated, sometimes implicitly, sometimes explicitly by different authors. And then I'm interested in seeing both the aspects of continuity and the aspects of change, you know, in each of these different moments of these stages in the history of that particular concept.

Peter Adamson: The idea then would be that if you look at like what Aristotle thought consequence was totally different, he doesn't, I mean, not only does he not form formulate these two criteria that Tarski did, but he doesn't seem to think about that way at all.

Catarina Dutilh Novaes: Well, actually. Aristotle has this famous definition of syllogismos in the prior analytics. And it says, it says a syllogismos, right? Which we often translate as syllogism, but some people prefer to translate it as a deduction because it's a more, it's a broader notion than just the technical notion of a syllogism. He says, a syllogism is a discourse in which certain things being stated, other things follow of necessity from their being. So, right, you must know this in Greek by heart, I presume, from the beginning of the prior analytics. And so, so he's saying when certain things are stated, so he says things in the plural, which already means that for in a relation of consequence in an argument, you need to have more than one premise, right? This is something that we don't entertain anymore. You know, we don't take single premise arguments not to correspond to valid consequences. Then he says, uh, certain things being stated, other things follow of necessity. So other things follow. So that means that he doesn't accept arguments where the premise, the conclusion is among the premises. And the way we describe this property in modern terms is that it's not a reflexive relation. So a reflexive relation, for example, if in the case of consequences, A implies A, right? And we-

Peter Adamson: Like Socrates is a human, therefore Socrates is a human. Exactly.

Catarina Dutilh Novaes: And this is thought to be one of the most essential properties of the relation of consequence these days, right? The reflexivity property. And Aristotle, apparently when he says other things follow, he doesn't seem to think that consequences that are reflexive would be valid at all.

Peter Adamson: And actually, I mean, just to sort of spell this out, to make sure it's clear, obviously a reflexive consequence satisfies the two criteria you mentioned before, right? So it doesn't matter what you put in. And certainly, if A is true, then it necessarily follows-

Catarina Dutilh Novaes: It's actually the quintessential example of necessary truth preservation, right? But Aristotle, so for Aristotle, it's the third clause in his definition of syllogism is follows of necessity. So in that sense, that part of the definition is still with us, right? And it's still thought to be perhaps the most defining feature of a relation of consequence, right? So in that state, right? So I mean, like I said, I'm interested both in what changed and what stayed.

Peter Adamson: And presumably your point is that you can't just sort of notice the difference between Aristotle and the contemporary concept if you want to understand the contemporary concept. Rather, you have to figure out where the changes were made.

Catarina Dutilh Novaes: Exactly. You need a narrative, right? You need a diachronic story. At least, I think it's very useful to have. So you start with Aristotle, you see what Aristotle's concept of consequence was and why it was formulated the way it was and my claim is that I've defended in print is that it's because for him, the relation of consequence and arguments such as syllogisms were mostly intended to be used in dialectical situations, right? So if you say, you know, I'm debating with Peter here and I tell him, you know, I say, do you grant me premise E? And then what do you say?

Peter Adamson: Sure.

Catarina Dutilh Novaes: Yes. So he grants me premise E. And so I say, and therefore, conclusion A. And what do you say?

Peter Adamson: I say duh.

Catarina Dutilh Novaes: Yeah, you say duh. You say, why are you wasting my time? Right? Exactly. So there's a reason why reflexivity is not a property that makes sense in a more dialogical, dialectical context. So these are the things that I think are important to trace. And then the formality criteria that I was mentioning just before with respect to Tarski is not basically not present in Aristotle, but already with the ancient commentators, right? In particular, Alexander of Aphrodisias, you see things going in this direction. So this is why you have a story, right? You have a narrative with different stages of development. And then it's really, I take it that it's essential to actually go through these stages to understand why it is that we think formality is such an important property with respect to the notion of consequence. And so you see where, where it emerged and why it emerged. And so that's with the ancient commentators. When we first had the notion of formality kind of creeping in, but not exactly in the way that we understand it. And then with the medieval authors, the Latin medieval authors, that's when it becomes this fully fledged criterion of substituted that we now see in any logical textbook page one or two of any logical textbook will tell you that this is what's characteristic of logic is that you can substitute, you know, if you take a schema and you substitute in whichever way you want in, in while you respect, of course, the right categories, that the argument will be valid. And that's something that developed later. So in the Latin medieval times, and so in this way, my claim is that this way you understand much better why it is that we take these properties of consequence to be the central ones, right? There are historical reasons for that, but we also get to think about the properties that once were thought to be important for consequence and now are not associated with the concept of consequences strongly as they used to be. So that's also very instructive because then you think about ways in which the concept could have developed and did it.

Peter Adamson: And so we actually wind up developing a keener and deeper understanding of what we thought was just our intuition.

Catarina Dutilh Novaes: Exactly. So I very much dislike talk of intuition, right? So the intuitive notion of logical consequence, it's not intuitive in some sort of pre-theoretical lay person way. No, there's a really long history behind it. And it's just become so familiar to us that we kind of take it uncritically and we don't realize that there have been many theoretical choices made along the way for it to be, you know, to have the specific shape that it has now.

Peter Adamson: Do you think that this is kind of genealogy? I mean, this actually reminds one of Nietzsche. And Nietzsche, when he gives his genealogy of morals, that seems to be a kind of undermining thing, right? Like, it's not quite clear what you're supposed to draw as a moral from the genealogy of morals, but it doesn't look encouraging.

Catarina Dutilh Novaes: That's a really good point indeed. So that people talk about, so one of the terms that has been used for this is that the kind of genealogy that Nietzsche engages in is debunking, right? So you can have a genealogy that's laudatory, right? So you can also have a genealogy that, you know, for example, if you genealogy in the common sense meaning of the term, right? So say if you go study your genealogy and you discover there was this really distinguished general, you know, yeah, okay, you're probably not happy with generals, but whatever, this would make you feel better about yourself. You will feel more distinguished, right? That would be kind of laudatory, positive kind of genealogy. But you can also do the Nietzschean debunking genealogy where what you do is you show that you may, you know, bring to the fore the shameful origins of a particular concept. But so one thing that I've developed, a proposal that I've developed in a paper that I wrote, which is called Conceptual Genealogy for Analytic Philosophy is precisely what I call a kind of like a neutral sense of genealogy where it's neither meant to be something that, you know, in no makes the particular concept that you're studying more valuable, but it's also not meant to make it less valuable. It's really kind of meant to be explanatory in the sense that you just kind of trace the different stages of changes, right? But other than that, other than the fact that I don't want to, you know, engage in genealogy that's necessarily going to be debunking, other than that, I'm very much inspired by Nietzsche because he has this really interesting conception of layers of meaning that gets superimposed. And so in a way, so there's a particular concept and with particular features and then, you know, given changes in practices and situations, then it kind of goes through a change and acquires a new meaning. But it doesn't mean that the old meaning disappears completely. So there are layers of the previous meanings that stay with you. And sometimes you don't even know why they're still there and they don't make perfect sense. They don't make good sense for the current practices that, you know, that are relevant for the particular concept, but they're still there. Right. So that idea, I think, is really powerful.

Peter Adamson: I think that might be, by the way, the first time the word Nietzsche has been mentioned on the entire podcast. I'm not sure I'd have to check. But actually, I want to ask you something completely different now before we stop, which is about the sort of other direction, because actually a lot of your work, especially some of your earlier work on medieval logic, makes heavy use of formal machinery. Like there are pages of your books where you open it and you just see symbols. Formulas and symbols. But it's about Occam, right? Or other scholastic medieval philosophers. And so you actually, at least have been in the past, a very keen proponent of using these kinds of modern formal methods from really what I would call mathematical logic. Symbolic logic to study medieval logic. And so I was wondering why you thought that that was a useful thing to do.

Catarina Dutilh Novaes: Right. So you mean why I thought it was a useful thing to do back in the day or what I think now?

Peter Adamson: Why don't you just tell us what you think now?

Catarina Dutilh Novaes: Yeah. So I still think so. There's something that I developed in the conclusion of my 2012 book called Formal Languages and Logic. So in the conclusion, I spell out the methodology of the whole book. And there I distinguish four approaches, methodological approaches that you can take in philosophy. And I don't mean to be exclusive, but at least four approaches that seem to me to be interesting and relevant. One of them is the historical approach that I was just describing, like the genealogical approach. The first approach that is kind of traditional conceptual analysis, right? That's kind of more traditional philosophical methodology. The third one is what I call empirically informed philosophy, right? Where you look at disciplines, say, empirical disciplines like psychology or cognitive science for relevant data for your philosophical analysis. And the fourth one is formalization. And I'm still very, very much interested in formalization, generally speaking, as a methodology. And in particular, and I think formalization is a very powerful methodology in philosophy across the board, but also in particular to study history of philosophy. So I think you can really come to new insights with respect to specific best theories by giving it a formalization, which really forces you to spell out the assumptions in a careful way. And by doing this, I think you can really obtain new insights on the particular theory or author that you're studying. And in fact, in the best case scenario, even if you have a really worked out formalization, you can even go on and maybe prove theorems about it, which will then tell you something new about the theory in question, which you might not have seen with just traditional conceptual analysis.

Peter Adamson: I see. So you might say Occam's or Buridan's theory of consequence actually has this surprising consequence that maybe they didn't see.

Catarina Dutilh Novaes: So that's true. So one thing that I proved with respect to Obligaciones, and I know that Obligaciones has been a topic also in the podcast, it's really technically it's a very simple proof. It's not like I don't claim to have proved something extremely sophisticated, but in my really very early work on that is that there's always a winning strategy for a respondent. So there's always a way in which respondent can maintain consistency. And this is something, just looking at it from the base of the texts, what the medieval authors themselves did is that they looked at a number of puzzles of sophismata, sophisticated cases, which seemed difficult for respondent. And it seemed like respondent could not but grant a contradiction. But what I did is by formalizing the framework, you can prove that there's always a way in which there's always an answer that's available to respondent that will allow respondent to maintain consistency. And so that's kind of something you can prove with these formal tools. And that's, you know, in a way, it's also interesting. I'm not saying that it completely replaces, you know, the careful textual analysis of all these sophismata, not at all, but it's complementary. And I think, you know, it's interesting.

Peter Adamson: So it's always possible to not lose. It's not easy as we learned in my interview.

Catarina Dutilh Novaes: Exactly. No, and the thing is that, I mean, the way I, the way in my formalization, I was only really dealing with fairly kind of like simple cases in the sense that there so often the what when it gets tricky in these Obligaciones games is when they're all kinds of references to the game itself, right? And then you like the what you have to grant is the previous proposition that I granted is false and things like that references to, you know, steps in the game itself, then it gets really tricky. Whereas the my formalization wasn't really taking this into account. But just at the level of just propositions that are being put forward, you can really maintain consistency because there's always like so between F, phi and not phi, one of them is going to be consistent with what you've answered before. And so there's always a way to maintain consistency. And so there's a winning strategy for respondent. Just to give an example.

Peter Adamson: One last question about this is something I worry about a lot, including when I write like sort of proper research on history of philosophy. I tend to be nervous about using, I mean, to say nothing of symbols and, you know, formulas. I'm even nervous about using an temporary terminology sometimes. And the reason is because I worry that that can easily be anachronistic and in particular that it might be anachronistic in ways I wouldn't notice. And there's an example of this that I like to give, which is the existential quantifier. So this is basically a symbol that looks like a backwards E and you can put that and then a variable, right? And it says, so it says backwards EX, that means there is some X, right? And the reason I don't think this is a good thing to do, if you're writing about at least ancient and medieval philosophy, is that I don't think that most of them had a kind of neutral notion of existence for which you could put in just anything. So for example, I don't think this would work in Aristotle. And so in my opinion, there's something kind of misleading and anachronistic to say anything about Aristotle using this symbol, the backwards E. And I mean, I claim to understand that. Maybe I'm wrong about it, but then I worry, well, maybe there might be other cases like that where I don't notice the unwanted implications that falsify the historical position I'm trying to represent.

Catarina Dutilh Novaes: No, no, I mean, that's a real risk. And in fact, it has happened. So in earlier work on formalizations of medieval logic, people were just using standard predicate logic, first order predicate logic, which is very much what you were describing in a way where you have the quantifiers and you have variables and they were using this framework, which was taken to be the logical framework to formalize all kinds of theories for medieval theories, for example, medieval theories of supposition and also modalities, right? And what happened, it's really actually it's extremely anachronistic and you have very, very strange things come out of this that are in fact, you know, highly problematic. And so what I did actually in my master's thesis, interestingly, that's like how far back in time it was, is that I was formalizing Occam's theory of supposition. And one of the first things I decided to do is I said, it doesn't work to use that straightforward traditional predicate logic, because then you have these quantifiers, you have these variables and you have the notion of function that plays an important role. And none of this, all of this is alien to the medieval framework. And so what I did is I started working with some sort of term logic, which resembles what Lesniewski developed. I don't know if you're familiar with this, the Polish logician.

Peter Adamson: It's definitely the first time this name has appeared!

Catarina Dutilh Novaes: The Polish logician Lesniewski, who had this system, which is really term based. So you have two terms and a copula, right? Rather than the function argument form of contemporary predicate logic. And I thought, you know, if this is completely wrong, this is going to mislead me completely if I use predicate logic and I really need to use a formalism that's closer to what was really going on in medieval logic. And so I was using this kind of term, the subject copula predicate notation, which is what it wasn't really inspired by Lesniewski, but in a way it was that's in that ballpark. And because that was much closer to what was really going on. So of course, there's always the risk of choosing the wrong formalism, right? To do to do that kind of analysis. And you should really be very careful in your choices. But it doesn't mean that it's inevitable, right? That it also doesn't mean that a certain amount of anachronism is not as long as you're aware of it. Because the formalism can still be eliminating if as long as you keep in mind that of course there's still this conceptual discrepancy here, right? I mentioned this before when I was talking, doing the formalization of Obligaciones, I didn't take into account these references to previous moves in the game, which is something that's important in this framework. I just simplified, it was a simplifying assumptions. I said, no, let's just look at propositions, you know, take propositions as my placeholders. But you know, knowing that this is a simplification, it can still be useful, right? So just you have to be careful with how you choose your formalism, of course. And there's always going to be some amount of anachronism, but it can still be justifiable and illuminating. But of course it can also go very wrong. And there are many examples of that. And of course, I will not mention names.

Okay, well, thank you very much, Catarina, for coming on again.

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Peter Adamson: Okay, so next, we're going to be talking to Russell Friedman, who's a professor of philosophy at the University of Leuven. Well, you're mostly an expert on lots of things, ancient and medieval philosophy, but you're best known for your work on, I would say later, scholastic medieval philosophy. And hence, you're a good person to ask, why should we care about late medieval scholastic philosophy now?

Russ Friedman: That's a good question. I guess one way to start looking at that is to think about what areas of philosophy might be most directly engaged, most directly relevant for contemporary philosophers that are dealt with in medieval philosophy. There, the first thing that comes to mind is philosophy of religion. Philosophy of religion in the Middle Ages is one of the main topics dealt with. It's true that a lot of the philosophers that we deal with in later medieval philosophy are in fact theologians. So for that reason alone, philosophy of religion is an important topic. And I think it's fair to say that contemporary philosophers realize this. So contemporary Christian philosophers of religion, for example, have a starting point. Let's take just one example. God's temporality. What kind of time does God live in or exist in, for example?

Peter Adamson: If any.

Russ Friedman: If any. That's exactly it. So the medieval view is that God is an omni-god. So God is as much of everything as possible. And this was sort of codified when it comes to God's temporality by Boethius. You may have mentioned this already in the podcast. Boethius gave a definition of eternity that it is the simultaneous and whole possession of unending life. And that definition goes through Thomas Aquinas in the 13th century and becomes really important in the current debate. Probably I think it's fair to say starting in 1981 with an article by Eleanor Stump and Norman Kretzman called Eternity. And they take their starting point from this medieval view. And since then, there's been a lot of discussion about whether God, how does God relate to our temporality? What kinds of problems does that create for God existing? The Boethian view is normally interpreted as saying, well, God exists all at once, no succession. And then it becomes a little more difficult to figure out is there duration for God? What type of duration? And how does God know things that we know? If God understands us, does he know our now of time, for example? And there's a huge discussion now, a big discussion at any rate, in contemporary philosophy. It takes a starting point in Stump Kretzman's article, which takes a starting point in medieval philosophy and has a tendency to look back on medieval philosophy as one way of approaching is God temporal? And today, contemporary philosophers have rejected the fact that God exists in time. God exists timelessly. And some contemporary philosophers like William Lane Craig, for example, will say, well, in fact, God is temporal. He began to be temporal as soon as God created.

Peter Adamson: And actually, that's an interesting example because Stump and Kretzman are really historians of medieval philosophy. And so this was not a case where you had some analytic philosophers of religion who were thinking about this anyway, and then they delved back into the medieval tradition, just hoping to find something. It was more a case where two scholars of medieval philosophy presented something to the analytic philosophy world and said, hey, this is a good way of thinking about God's temporality or lack thereof.

Russ Friedman: Although, to be added, that both Stump and Kretzman were trying to act as contemporary philosophers of religion. So it's very, very tight there, the link between the medieval philosophy of religion, or what we would call philosophy of religion, what they might call theology, and contemporary philosophy of religion. Yeah.

Peter Adamson: Isn't this the kind of the exception that proves the rule? Because I could imagine someone saying, well, sure, of course, the medievals are interested in religion, and all they do is go on and on about God. Actually, I've tried to show in the podcast series that this is not the case. But a lot of people would say all that medieval philosophers have to say is about God. So the one area we would expect contemporary philosophers to be able to learn from the medievals is this area, namely philosophy of religion. But otherwise, we can ignore it.

Russ Friedman: Yeah. I mean, I would be tempted. First answering that question, I would say, well, no, there are other areas as well. One can point to fruitful exchanges in, for example, metaphysics. John Duns Scotus' views on universals have been used in current philosophy of science. Ethics is another example, a very good book on Thomas Aquinas written by Robert Pasnow and Christopher Shields. They begin the section on Thomas Aquinas' ethics by saying that, in fact, doing ethics or studying ethics is in fact studying the history of ethics. And so Aquinas, they argue, should be someone that we study in the canon of ethical works. With that said, so I do think that there is some lessons to be learned from going back to medieval philosophy. And it's one of the reasons why perhaps contemporary philosophers should be interested in medieval philosophy. With that said, I have a pretty historical approach to the history of philosophy myself personally. And if I were going to try and convince someone, I try and convince my students. Every year I have students in the history of medieval philosophy course I teach. And what I say to them is, in fact, what medieval philosophy offers you is the opportunity to challenge your own intuitions, challenge your own philosophical views that you might not even be aware of that you hold as tightly as you do. So for me, the weirder, the better, the more historical, the better, the more context you give that sort of fleshes out what these views are and how different they are from our contemporary philosophy, the more interesting it is. Because it allows you to take, and this is the example I give again to my students, it allows you to take a mental vacation. Some people when they go on vacation, I don't know how your vacations are, Peter, but when I go on vacation, a lot of times I just go to suck up another culture, try to be challenged in some way to do something that's just different from my normal everyday life. That's what medieval philosophy, ancient philosophy too, I'd say also early modern philosophy, if you look at it contextually, it also has a lot of God in it. It offers you a chance to challenge your views and allows you to take a step back and think okay, why do I hold that? So maybe instead of having just some very particular use going back and looking at medieval philosophy and saying, well, I want to use it for X, you should rather say, well, this is a way of having some mental hygiene about my own views and thinking a little more broadly and more deeply about them. And you may not know when the payoff is going to come.

Peter Adamson: And that means that the very common experience of reading historical philosophical work and thinking 'what in the world is this person talking about?' on your suggestion would in fact be one of the most productive moments in looking back at historical texts. So it's not the moment where they give a little argument and you think, oh, that sounds like a good counter objection to something that one of my colleagues said the other day. It's where they say something that you really can't fit into your philosophical framework at all might be the most kind of useful moment in reading it.

Russ Friedman: Yeah. Especially if you take the time to figure out what they're trying to say so that you allow it to sort of sink in and be a counterbalance to your own sort of background assumptions, I guess I'd say. Sure. Definitely.

Peter Adamson: But what would you say to someone who objected to this that it's unlikely that someone who's living in 13th or 14th century Europe with all of the social, political, metaphysical, religious presuppositions they had, is it really very likely that the things that they cared about that we don't care about are the right things to care about?

Russ Friedman: I guess I'd say that they, well, on a very general plane, I'd say, well, they were human beings. They cared about things like good and evil. How do we act morally? What is acting morally? That sort of thing. I guess one example that one could give of this way of challenging oneself is something that you've talked about actually in several of the earlier podcasts. You've also talked about it actually, I think, on one of the podcasts in Philosophy Bites. And that is the ancient and medieval, actually it's a view that goes all the way up to Leibniz, you can say, that goodness and being are convertible so that everything that exists insofar as it exists is good. And the flip side of that is that evil doesn't exist. Evil is an absence of goodness. And when I tell my students that, say, Thomas Aquinas, that happens to be the text that we work on, when I tell my students that Aquinas really believes that evil doesn't exist, he believes that blindness is not a thing, it's the absence of sight, well, that's how it works with all evil, they say, hold on, I mean, a virus is bad, right? Viruses cause illness and it's bad for people. And yes, it's bad for people, I have to say, but Aquinas would argue that, well, it's not bad in itself. Insofar as it exists, it's good. And of course, Aquinas has a good reason for wanting to believe that as a 13th century theist, here maybe we play back into your objection, well, do they have the same view? Aquinas wants to say that everything that God created, including viruses and nasty bacteria, etc., those things are good because God created it and what God created is very good. But he also has arguments for it, arguments that go back to your Neoplatonists, for example. So one way of arguing towards that view is an Augustinian, which is a much more Neoplatonic view. Augustine takes a definition, he says that to corrupt something is to make it worse. What happens when you have a good thing that you make so bad, that you corrupt so much, that you make it so much worse that it can't get any worse? All the goodness is gone. Well, Augustine says either you can say that it's become incorruptible, but Augustine says that's stupid because that means that you've made something so bad that it's become better because it's incorruptible now. Or you say it's going out of existence. It's lost so much goodness that it's gone.

Peter Adamson: Yeah, the example I like to give of this is take a really good beer. We're actually in Belgium right now. Yeah, I mean, so take a good beer and make it worse. So reduce its flavor character and so you maybe turn it into something more like American beer. And if you've made American beer even worse and you take away its flavor and so on, then eventually you get to something that isn't beer anymore. And then you say, well, but maybe it's still liquid and so it can still refresh thirst. So there's still something good about it. Take that away. And eventually you just have to pour it out and get rid of it and it's gone.

Russ Friedman: It is no longer what it is supposed to be. Right? That seems to be a reasonable argument. You could object to Augustine, of course, that he's defined sort of in a way by saying that corruption is the taking away of goodness. He sort of defined his terms in such a way that he's going to get the answer he wants. But what is evil then? I mean, it seems to be a reasonable question. We have to say, well, you could say, well, I'm just adding evil. Well, then what is it?

Peter Adamson: Right, and it's not like the question of what evil is has gone out of style or something. It's something we still should care about. Yeah. Actually, one interesting thing about your example is that it goes along with one of my favorite examples of an idea that's very prevalent in ancient and medieval philosophy that's no longer on the philosophical scene, as far as I know, which is that being comes in degrees. Because what you were saying is, well, take something that has being and reduce its degree of being, that will make it more evil. And if you decrease its degree of being until all of its being is gone, then you wind up with non-being, which would be pure evil, and then pure evil can't exist. Whereas most philosophers nowadays, I think, would say that if you have two objects, one object can't be more than another or exist more than the other.

Russ Friedman: Yeah. No, this is actually... I asked my students about this when I taught, teach this class. I make a contrast between an analog vision of being and a digital vision of being. So a digital vision of being would be, it's either on or off. A stone exists as much as Peter Adamson does, whereas an analog vision of being says, well, stones exist less than cows do, and cows exist less than people do, and people exist less than, let's say, angels or God do, right? And there's a hierarchy of being in some way. And I think I agree with you that it's gone a little out of focus, although I've noticed that my students become more and more attracted by the analog vision of being as opposed to the digital. So I don't know what that says about...

Peter Adamson: Is it you corrupting them?

Russ Friedman: It could be. They find it more convincing. But this is just, I think, a good example of a view that, yeah, it would challenge our own preconceptions that being... If you start presenting or reading medieval authors on the convertibility of being and goodness, so the fact that everything that exists insofar as it exists is good, and the privation theory of evil, it would present a challenge to your own notions of what it is to be, what it is to exist, and what the relation between existence and goodness is, and further, what is evil?

Peter Adamson: What about another kind of obvious complaint or worry that people might have about medieval philosophy, which is that it's very authority-bound. I mean, if you look at Aquinas and not only Aquinas, pretty much any scholastic medieval philosopher, they're constantly quoting authorities, not only Christian authorities, but often Christian authorities, the Bible Church Fathers, but then also Aristotle, Avicenna, Averroes. And you sometimes get the impression that they felt like they weren't allowed to move beyond the bounds of theses that could be found in authoritative texts.

Russ Friedman: I'm glad you asked about that, because it's one of the things, when I was a graduate student, it really bothered me, especially reading works about early modern philosophy, maybe Renaissance philosophy, and looking back and saying, well, medieval philosophy is just so hide-bound. All they do is quote these authorities, and there's really no room. They don't want even to be innovative and creative on their own. And it's one of the things that I've actually looked at quite a bit. I've written a lot on Trinitarian theology, and Trinitarian theology is a great example of a text-based area of research. You could say a research area in medieval philosophy. They have Bible passages, they have Church Fathers, as you mentioned, plus they bring in also the Greek philosophers, the Arabic philosophers, they use them as well. And what I found, first off, I think that the word authority, auctoritas in Latin, often means something different than we mean. If we say that it just means authority, yeah, that's right. But normally when it's used in a medieval text, what it means is an authoritative passage. It means a text that you're quoting and not just sort of like Anselm's My Authority or Augustine's My Authority here. It's Augustine, De Trinitate, Book 15, blah, blah, blah. That's what the authority is, is an authoritative text. So that's one thing that maybe modifies or nuances the view that you're talking about, that medieval authors are just authority-bound. But the other thing is that, so I have an example, John Duns Scotus, when talking about the Trinity, he quotes John Damascene, a huge authoritative figure in the Middle Ages. He actually has, he's quoted all the time and is quoted in this passage by Scotus as an auctoritas. In fact, Scotus gives three auctoritates and one of them, Scotus says, yeah, we could interpret it this way, we could interpret it that way, but ultimately it looks like John Damascene was just wrong. It's about the Filioque, the idea that the Holy Spirit comes from both the Father and the Son. This is doctrine for the Latins, the Greeks objected, and John Damascene was giving the Greek point of view and Scotus says, well, Damascene was just wrong there. So you can have an authority that can basically be thrown away. And so the way that I think that we should look at authority is less as sort of a constriction on what later medieval or medieval thinkers could think and more like the way data points function for say a chemist or a physicist, a physicist or a chemist comes up with an experiment, they do experimental, they conduct the experiment and they have a bunch of data points which they try and figure into some kind of mathematical model, this is just an example. But some data points that don't fit and just as with those experimental data points, they in some way or another put limits on the theory that you can come up with, nevertheless, if they don't fit, they can be thrown out. And that's I think the example from Scotus, but I can give other examples, shows that what an authoritative passage was, was something that you needed to deal with in a particular context but it wasn't necessarily something that you had to agree with. It was something that you had to take into account, it had weight, but it didn't necessarily say well, that's what you have to believe, right? Even if it was easy figuring out what an authority to passage actually meant, right? So this is really nice quotation from the 12th century, I can't remember actually who said it, but "authorities have noses of wax, you can bend them any way" and that's what medieval authors did. And so in a way, the authoritative background was a spur, a motivation to be a little creative. How do we deal with these authoritative passages in such a way that we can pull them into our theory without them dictating to us what our theory is?

Peter Adamson: Is there a sophisticated thought behind that whole process where they, even if they're not committed to the idea that every authority, every text that you might cite from their favorite group of authoritative figures, even if you can't assume that everything they ever say is right, there's still kind of a presumption that they're right because they were great thinkers or they had maybe a better historical access to the truths of the Bible or Aristotle or whatever. What's the kind of grounding assumption that makes them use authority as if it were a set of data points?

Russ Friedman: Well, that's a good question. I don't know whether I have an answer to it. I mean, I think that one thing that sort of constraining job gives you the set of authorities that you need to deal with is tradition, right? If you're discussing a particular issue, let's say, Trinitary theology, there's going to be built up over 500, 600, 700 years, a group of authoritative passages that have played a role in creating the doctrine. This is going to be true in physical treatises or more philosophical areas. In metaphysics, for example, you're going to have quotations from Porphyry, from Avicenna, for example, and those will have been built into the tradition of discussing on this topic over many years. That's why they need to be dealt with because otherwise you're ignoring, it's like ignoring data points, right? You can't just ignore the data points. They're there, but you need to be able to say something about them. Is that an answer to the question that you posed, you think?

Peter Adamson: Well, I guess the question is why do we do philosophy in a tradition, within a tradition instead of doing what Descartes, for example, claims to be doing - even though it's not really what he's doing, which is kind of throwing it all out and starting with a blank piece of paper - which I think is the way a lot of people think philosophy is supposed to work. Of course, if you look back over the history of philosophy, you can see that hardly anyone has ever done that. And so maybe what we should say is that at least the Medievals were conscious that they were doing it. Since everybody does it, it's better to do it consciously and not stage this hypocritical self-presentation where you pretend to be starting with a blank piece of paper, but then actually you reproduce a whole bunch of scholastic arguments, which is what Descartes does in the Meditations.

Russ Friedman: Yes. I prefer to have people who have the intellectual honesty, I guess, I mean, that's a little much, but to admit that they're in fact engaging with an earlier tradition. I think that everybody does. I think that we do it today, although the intellectual tradition maybe only goes back 20 or 30 or 40 years, right? For a contemporary analytic philosopher, maybe 100 years. But in the Middle Ages, of course, they went back farther. One of the defining features, I say, of medieval philosophy is that engagement in the case of the medieval Latin West in a Catholic context with ancient and Arabic Jewish philosophy, as well as the theological issues. For them, it's really of the essence of the philosophical project, I'd say, to deal with what's coming out of the bedrock philosophical tradition, Plato, not so much in the Latin West, but Aristotle definitely, and then all the stages along the way with Boethius, Augustine, Avicenna, Averroes. Taking those things into account, that was what they had to do. They felt maybe a deontological sort of necessity to deal with these things. I have a feeling that it's doing them a disservice to look at that as being some kind of a straightjacket that means that they can't be original, they don't have anything to offer. In fact, it's one of the ways that they express their creativity, I think, most clearly by dealing with these authoritative passages and coming up with ways of balancing them out.