Today, I want to move to a different focus. We'll be talking about Antonio Damasio's book, Descartes' Error. In the course of which we�ll be emphasizing the emotions and the role that emotions play in human reasoning. And of course, in doing so, we're going to be thinking about aspects of self-knowledge that are there, in a sense, open to consciousness but perhaps are aspects of consciousness that are not things that strike one's attention immediately. Once we hear about some of Damasio's hypothesis, you might find yourself paying attention to things that had been available to your consciousness all along, but that you had not been paying attention to until they were brought to your attention. I'm hoping that's what we can bring to the surface before our time together today is done. So first just some background. A big distinction that I want you to have before your mind as we get ready to plunge into Damasio's thought is the distinction between two kinds of rationality. Rationality takes two forms, neither of which is reducible to the other so far as I can see. Theoretical rationality is that aspect of reasoning that attempts to answer the question, what is the case. We employ theoretical rationality in determining what the weather's like outside, how long ago the dinosaurs died out and what made them die out. We would employ theoretical rationality in doing a mathematical proof, we employ theoretical rationality even in predicting what the future will hold insofar as we're able to do that. So theoretical rationality uses logic, it uses evidence, it uses an empirical basis so far as possible, also reasoning to come to conclusions that are justified by the evidence that we have available to us. Whereas by contrast, practical rationality answers the question not what is the case, but rather, what should I do, more precisely, what is the most prudent to do? Practical rationality attempts to develop a kind of theory or mechanism that will help us make progress with the question, what shall I do? I'm taking it that theoretical rationality is relatively familiar, and you employ practical rationality just about every day of your life, without perhaps having spent any conscious attention on the question, what is practical rationality and how does one pursue it. It it going to be useful, because in our discussion with Damasio, we'll find him making assumptions about the nature of practical rationality that might or might not be quite right. But that he will be arguing for the importance of the appeal to any indication of emotion in one's application of practical rationality. So that's one thing that I want us to pay attention to, that will be one important focus for our discussion today. So what is practical rationality? Think of yourself as making a decision about what to do, and as such, you have a number of available actions. In addition to those options that you have, there are a number of possible states of the world that you can contemplate. And once you differentiate among the actions and the possible states of the world, you then can think about outcomes, that is to say, what happens if you perform one action and the world ends up being a certain way? And then, in the course of making a decision, one way to approach this is to assign a value ranking to the possible outcomes that you have available to you. This is what we call the Act-State-Outcome Approach to decision-making with a little bit of quantitative information added in. So suppose we're deciding whether or not to take a vacation to the beach, and we're going to distinguish between taking a beach vacation and not taking a beach vacation, those are two actions that are available. And you can distinguish between lousy weather and decent weather. We're deciding whether or not to go down to the beach for the day and deciding whether or not it is worth our while. Well, the outcome for choice that you make of taking the beach vacation and getting lousy weather is that you lost time, then probably some money getting there. Perhaps you rented a place by the beach and that money will have not been very well spent. Whereas, by contrast, if it's decent weather, decent weather means acceptable all the way up to excellent, you would take a beach vacation, you might have spent money and time, but hopefully, you will have had a good time frolicking in the waves. By contrast, for the row of this matrix that corresponds to not taking a vacation, if it's lousy weather, then the outcome is that you had no loss of time or money. You might even feel a little bit of gloating about the fact that people who are at the beach have to stay inside doing board games or something in order to wait for the bad weather to pass. Whereas, if you don't take a beach vacation and the weather's decent, you will, as before, have no loss of time or money, but you might feel some regret as you're friends send you texts and Instagram messages, and things of the kind, showing you pictures of the great time they're having in the waves. And you could also begin to add some numbers to these outcomes, that is to say, if I take a beach vacation and it's good weather, that's the highest, that's four. And likewise, you can see in this matrix all the way down to one, where I take the vacation as bad weather and I'm wishing the rain would stop. In addition, in order to make this a little more precise, we would want to add probabilities to the various possible states of the world. That is, if there's just a negligible chance of bad weather, then that'll make a big difference for the rationality of doing one thing as opposed to another. But let's suppose that we consult historical weather records and we look into any forecast that might be available for the coming week for that part of the world and we say, well actually, 50-50 chance of good weather as opposed to bad. And likewise, you might say, in addition to just a ranking of the outcomes, 4, 3, 2, 1, let's put numbers that correspond to how much we like one more than the other. So suppose we've got a scale of 1 to 10 to use, we can give 10 to the outcome in which you take the vacation and the weather's good, all the way down to a 1, to the outcome in which we take the vacation and which the weather's bad. Once we have that information, we can begin to, so to speak, multiply through. That is we balance the value or disvalue of the outcome with the probability of that outcome actually taking place. The result being that for multiplying the products and then adding across, we get what's known as an expected value for taking the beach vacation and expected value for not taking the beach vacation. According to what this sort of development of the Act-State-Outcome conception of decision-making, the development known as subjective expected utility theory, or SEUT, is going to say, the rational thing to do is going to be to take the vacation because that has the higher expected utility, than does not doing so. And as a result, it seems like if the question is, is it prudent, this is prudential rationality, practical rationality, is it prudent for me to take the vacation under these circumstances? The answer, according to this way of reasoning, is going to be yes. This is, you can think of this as a kind of system, mechanism, or even a technology for helping you to decide what to do in a complex decision situation. Now, a couple of clarifications I want to add about this. First of all, there is an element of subjectivity here that's built in to subjective expected utility, and that differentiates the process from what you're doing with theoretical rationality. With theoretical rationality, there's no obvious place for subjectivity to have a role. Whereas for practical rationality, it depends a lot who you are and how much you value or disvalue certain outcome. So if you're the sort of person who just loves rainy days staying inside the house or hotel, perhaps by a fireplace doing a puzzle or something, if that doesn't bother you at all even though you made an effort, in the hope of going on vacation and frolicking in the waves. If it's nearly as good for you to be inside doing board games or making puzzles or something, that's fine, but that will result in a different number that you would put in that relevant part of the outcome space from what somebody else would do if they're very disappointed in that outcome. Likewise, two people could look at the same weather forecast and on that basis, still each act rationally with one taking an umbrella, the other one not taking an umbrella because one, for example, gets very, very bothered by getting wet when they get rained on. The other one doesn't mind at all. So the S part of SEUT, S-E-U-T, matters. There's an element built in of subjectivity to this theory, and it's different in that respect from theoretical rationality, which has no obvious place for subjectivity. The second point I want to make is that, there's nothing built into the definition of subjective expected utility theory that says, in order to behave rationally in this practical sense, you have to build a decision matrix. You can, that's optional, but not required. And in fact, it had better not be required because building a decision matrix is an action. And then, when you're contemplating an action, if you always have to build a decision matrix to decide whether that action is a rational thing to do, you would have to build a decision matrix to decide whether to build a decision matrix, and that's going to end you up on a regress. So what I'm going to call the decison maker's regress is one that should not be a problem for SEUT, but rather something that would show that it's obviously not the case that whenever you've got to make a decision, you have to build a matrix. The matrix is sometimes helpful but it's certainly is not mandatory. We can see a similar point by just noting that choosing an option, even in a way that's practically rational that maximizes your overall well-being, does not require that you consciously do so. There maybe lots of things that you do automatically paying little or even no conscious attention to what you're doing that still are going to be the most reasonable things to do under the circumstances. Likewise, following your gut may be a perfectly good way of maximizing subjective expected utility. And you can see this in obvious cases such as, suppose that you're walking across the street, and a bus is out of control, careening towards you. By no means should you make a decision matrix in order to decide what to do! I strongly urge you to jump out of the way, try to save as many people with you as you can. But of course, you're not making a decision matrix in the process and yet, you're still probably maximizing utility by jumping out of the way of the bus. So there are plenty of reasons to think that maximizing subjective expected utility does not require that you pay conscious attention to the process by means of which you do so. Often doing what comes naturally is precisely the best way of maximizing subjective expected utilities. So I've distinguished between practical and theoretical rationality, and we have talked about theoretical rationality before. Descartes had developed an understanding of it, that puts pride of place on the idea of clear and distinct perception. We might not agree on that particular formulation of theoretical rationality, but it's a nice example that dramatizes part of what's important about the process. Practical rationality, which I'm introducing now, has to do with doing what's prudent. And there's a method, a kind of technology for applying it, but it's something that is optional, not required. A good idea to use in a complex decision situation about where to invest your money, things of the kind, but often immediate time-sensitive decisions require that you not consciously do it, go with your gut, and in many cases, you will still be maximizing subjective expected utility, and thereby acting the way that's practically rational.
