 In part three of the lecture, I want to talk about how character virtues and faculty virtues are related. I want to suggest that the character virtues can contribute to the faculty virtues by making them function better. So insofar as the faculty virtues have the function of getting us at the world, they get us truths and hopefully knowledge in different domains of reality, it's plausible that the character virtues can actually help the faculty virtues to function better in that respect. So to get a feel for how that might go, I want to first make a distinction that we make in epistemology, which is between reliability of a faculty and the power of a faculty. So reliability is a matter of the ratio between true beliefs and false beliefs. So for example, excellent perception is highly reliable in the sense that it almost always delivers true beliefs and almost never false beliefs about say midsize physical objects under proper perceptual conditions. So reliability is not infallibility, it's not that perception can never lead us wrong, but perception is highly reliable in that it almost never leads us wrong. It's going to give us a high ratio of true beliefs over false beliefs. Now power is a different notion. Power is a matter of how many true beliefs a faculty delivers. Next thing to see then is that reliability and power can come apart. And in fact, there's often a trade-off between reliability and power. So for example, you might have a perceptual faculty that's highly reliable, but with very poor power. Imagine a person, for example, who is extremely careful about any judgments they make about an object's shape. So they refuse to make a judgment about the object's shape until they get to go all the way around the object and look very carefully and then they'll say, oh, that's a cube. Or they might do the same thing and decide, oh, this is a sphere. Now that person presumably is going to have extremely reliable perception because they're being so careful it's going to be very hard for them to ever make a mistake. But they're going to have poor power with their reception because they're going to get very few true beliefs. I mean, they're just not going to just rely on the normal perceptual cues that we can tell a cube from a sphere without walking all the way around it and making absolutely sure about the shape. So that's the way then where you can have very high reliability but at the cost of power. You can also have great power but at the cost of poor reliability. So that's fairly easy to imagine as well. So for example, if you were just extremely trusting of your perceptual faculties and you're ready just to believe perceptual appearances as soon as you get them without ever checking, well, you'd get a lot more true beliefs because the perceptual faculties are going to be delivering you a lot of truth but you're going to make more mistakes as well. And so you're going to have an increase in power but a decrease in reliability. So now, presumably, intellectual excellence with respect to our faculty virtues is going to involve a good balance between reliability and power. And now we can make the point I was getting to, which is that the character virtues can contribute to both the reliability of our intellectual faculties and to the power of our intellectual faculties. And it can also contribute to achieving the right balance between reliability and power. So for example, take the intellectual virtue, the intellectual character virtue of intellectual carefulness. Plausibly, intellectual carefulness will make our reasoning faculties more reliable. I'm careful about how I gather evidence and I'm careful about how I make inferences from that evidence. I'm more likely to get things right and therefore there will be an increase in the reliability of my reasoning powers. On the other hand, a character trait like intellectual courage will plausibly increase the power of a reasoning faculty, to say that it's possible to be too careful, too timid in the way, for example, that we reason in a domain. And as a result, we'll lose out on knowledge that we possibly could have if we were more courageous and willing to reason with a bit more courage.