Our Midterm is coming up soon (October 25th).
This course has a lot of readings, and so I am releasing a mid-term study guide, which will tell you where to focus your preparation. These are the page ranges where we focused, and where the arguments that will be at issue on the midterm can be found. Obviously there’s a lot more in these texts, but in our course, that additional content has been used to set the scene for what we examined in the page ranges below.
Aquinas 49-50, 52-53
John of Salisbury 64 (Description of Platonism)
Henry of Ghent 108-109
Duns Scotus 110-111
Henry of Ghent 128-129
Nicholas of Autrecourt, 139-141 (§11, 22, 23)
John Buridan 144-147
Aquinas 157-165, 166-167
As Liz pointed out (thanks Liz, I would have forgotten) there's a great conference at DUC next weekend (the 19th - the 21st) on Epistemology and Its History. I'm going, and it looks like it will be a good bunch of papers. If you're curious about epistemology, this would be a good conference to take in.
You can read more about it here.
Today we looked at several philosophers as they dealt with the age-old challenge of scepticism.
One way to divide up what we read is to think of different sceptical questions, which met with different answers from our philosophers.
A mild sceptic might say: “The senses deceive you sometimes. They deceive you, for example, in cases of illusion. Therefore you can’t trust them any of the time.” We saw Aquinas reply: “No, the senses don’t deceive us. If we see the sun in the sky, it looks small because it is at a distance. If we judge that the sun is small, we’re making a mistake in judgment, not in our senses. So if we control our judgements we will see that our senses do not mislead us at all.” But Aquinas is not very interested in the problem of scepticism.
An extreme sceptic might say: “You don’t know anything at all. Because you could be deceived about every single thing you think you know.” We saw Augustine replying that there is at least one thing he knows. Even if he is deceived, he knows that he exists. Our own existence can be known, whatever else is true.
A middling sceptic might say: “For all you know, the world could be totally unlike what you think it is.” Henry of Ghent gave a variety of arguments against the sceptic. Ultimately, Henry is willing to allow that there are things about which we are uncertain, because our knowledge of essences is assured by divine illumination. Still, he needs an argument against the sceptic. We looked at an argument he finds in Cicero, from the possibility of craft. Sceptics say we may not understand the world, but craftsmen act on the world and produce results in a reliable fashion. Doesn’t that prove that what the craftsmen do depends on true knowledge of the world?
One of the philosophers we read, Nicholas of Autrecourt, took the position of the sceptic. His argument, though somewhat complex in its exposition, boils down to this. Autrecourt’s former teacher, Bernard, said that the sceptic could never attack the principle of non-contradiction, i.e. The logical law that a thing and its contradictory cannot both be true at the same time. (For example, it can’t be raining and not raining at the same time, in the same way.) Now here’s Nicholas’ point. Bernard wants to go from the principle of non-contradiction to facts about substances (i.e. Natural things, like cats and people) and causes and effects. But all of those things are possibly different. In a science-fiction story, there might be different animals, and different causes, meaning that what is true here could be false, without contradiction. Since it could be false without contradiction, there’s no way for Bernard to have certainty about ordinary life, even if he can be certain of the law of non-contradiction!
Finally, we saw Jean Buridan (a contemporary and friend of Nicholas’), who tried to grant some of Nicholas’ point without being sceptical. Burden points out that, even if we grant the logical possibility that God could make things different, all we have to do is assume that God will act in regular and stable ways (not a huge surprise if God is rational and wants us to understand the world!). If we make that assumption, even though it’s not logically necessary that things in the future will go on the same way they have in the past, it’s still a safe bet.
Today I was trying to formulate a very simple point: one man’s modus ponens is another man’s modus tollens. For example, suppose lazy A says to B:
If you want to be my friend you have to wash my car for me.
Of course you want to be my friend.
So you have to wash my car.
But B replies,
Actually, I’ll grant your point.
If I wanted to be your friend, I would have to wash your car.
But I don’t care whether I’m your friend.
So I don’t have to wash your car.
The logical structure is:
If A then B
Can easily be turned into
If A then B
So, can Henry of Ghent’s argument be turned from a modus ponens into a modus tollens? Henry says something like this:
If we are safe from skepticism, it’s because we have divine illumination.
We are safe from skepticism.
So, we have divine illumination.
If S, then D
One way to turn this into modus tollens would be to say:
If we are safe from skepticism, it’s because we have divine illumination.
But divine illumination theory is impossible to believe.
So we are not safe from skepticism.
If S then D.
It’s not such an attractive argument, because we don’t want to end up with the conclusion that nothing can be known, which is what the skeptic maintains. On the other hand, maybe it is unreasonable to suppose that we are safe from skepticism.
Today we considered the theory of divine illumination. The theory, which is nicely summed up by Aquinas on page 88, holds that we see universals in God’s mind. This means that God gives us access to the complexities of things. Now, no medieval philosopher wants to deny that it is thanks to God’s creation and preservation of us that we can do anything, including knowing anything. But only two of the philosophers we read got on board with the theory of divine illumination.
Augustine and Henry of Ghent defend divine illumination theory - Augustine more generally than Henry does. Augustine thinks that in order to understand the structures in things, we will need to see the perfect exemplars of those things in God’s mind. Henry makes the point more narrowly: sure, we can find out facts about the world on our own, but if we want to know the essences of things, what they really are, that simply isn’t out there in the world, which is why God must help us understand. After all, what’s the alternative - that we don’t know anything about what exists in the world?
Aquinas and John Duns Scotus think that we don’t require divine illumination. We read in Aquinas a sophisticated account of how we abstract universals, to understand them: we consider the universals in things but independent of other elements of that thing. So if I want to understand the shape of a horse, I consider it independently of the movement, the snorting sound, the smell, the colour, etc. In Scotus, we found a careful critique of Henry. Henry uses the idea of divine illumination to get these perfect ideas into our minds, but if our minds are imperfect, doesn’t that mean that these ideas won’t really belong to us and won’t be understandable by us?
Today we looked at a family of texts generated by comments in an introduction in a work of Porphyry, a 3rd century AD Platonist. Porphyry wrote that some problems about universals were interesting, and 1000 later, scholars were still debating the questions he raised!
Porphyry asked about how ‘predicables’, specifically genus and species work. Really, he was approaching universals through language. Universals are entities that can be said of other entities (in language), because they can be in those entities (in metaphysical fact). So for example I can say that your shirt is red, because redness is in your shirt. I can say that you are a human being, because human-being-ness is in you.
But what are we committed to when we talk about human-being-ness? Or redness? There is a continuum of possible views:
We saw several answers.
Plato and Augustine think that things like human-being-ness or redness are the plans, the structures of the universe. These exist independently - Augustine would say, in the mind of God. This means that knowledge of these deep structures would give us knowledge of the universe. And maybe the only way to make sense of our ordinary language, and our constant reference to things like redness is to suppose that these things actually exist, somehow.
Boethius argues that they do not exist. One argument depends on showing that if they do exist, they must be one or many - but neither description seems to work.
We also looked in detail at William of Ockham. Ockham thought that the act of the mind thinking about a thing was enough to function like a universal. When I think of human beings in general, I make my thought a ‘natural sign’ of human beings in general, just as smoke is a natural sign of fire. Smoke just stands for fire, full stop. Why can’t my thought function the same way? In effect, he is deflating the traditional problem. Why do so? Well, it is simpler, for one. But also, Ockham launches a number of attacks on realism and even conceptualism.
Today we encountered two philosophers considering the question of how to conceptualize “science”, which we should remember, means knowledge. Both philosophers, in the medieval tradition, are concerned to fit Christianity and Philosophy - faith and reason - together. Both philosophers were trying to fit Christianity into a map of what can be known.
Augustine argued that the way to do this was to embrace and augment the philosophical tradition of Platonism. Platonism, he argued, covers the various areas we need to understand to understand the world: logic, physics, and ethics. But Platonism is also an attempt to discuss the One, Intellect and Soul, a threefold hierarchy that Christians easily identified with God. Moreover, Platonists are already committed to the immortality of the soul, and to the existence of Forms (abstract structures existing independently of what is structured). All these committments are welcome to Augustine, who concluded that Christians could adopt the philosophical methodology of the Platonists.
St. Thomas Aquinas lived after the influx of Latin translations of Aristotelian texts. His project was somewhat similar, but he was working with a more complex picture of the sciences, which we encountered in the selection from the anonymous author for this week. And Aquinas question is narrower: is theology a science? Remember, this really means, is theology the kind of knowledge we can organize, understand, and in which we can attain certainty? It might seem the answer would be no, but Aquinas rests his case on the contention that the principles of theology are God’s revelation, and the fact that God is a perfect testifier, which means that whenever God tells us something, what He says must be true. This means that theology has the most certain of all principles, since, if we have received them correctly, we know that as the revelations of a perfect being, they must be true. Not only that, but theology is aimed at our salvation, because it brings us to God. That’s why theology is at the top of knowledge, both theoretically and practically speaking.
Today we talked about the medieval period - thousand years or so of history we're going to be studying.
We also had a look at a couple of St. Thomas Aquinas' articles on angels in relation to location. We start with what is a fairly obscure theological question, and soon find ourselves thinking about how souls connect to bodies, how human bodies are produced, and theories of causation. That's often how it is in Medieval philosophy. But notice also how Aquinas writes: he's so careful to include other philosophers, as well as the Christian tradition. Faced with a problem, his instinct is to make a distinction. That - here's my take - is necessary if you're going to take on the project of showing that ancient philosophy and Christian doctrine, pagan reason and Christian faith, can be in agreement. And that, of course, is the medieval project.
This is going to be our course blog. After the classes, I'll usually add something here. Feel free to add your own comments and keep the discussion going.
DPHY 1211 A will be getting started in a couple of days. No need to do any readings for Wednesday the 13th, but you should start thinking about whether you are going to acquire a paper copy of the textbook. As you can see from the syllabus, you have options there.
See you in a couple of days.