Rhyme and Reason

What does it mean to be rational?

We hear the adjective every day, and it’s usually taken to be a positive thing. On TV, characters snap at one another, “You’re being irrational about this!” when they mean, “You’re wrong!”; and calling a person “rational” implies that he or she is intelligent, a clear thinker who’s able to put aside distractions like feelings while under pressure. We think of Mr. Spock: cool, calm, collected, and always right.

But what is rationality? Shows like Star Trek, House, M.D., and Bones seem like they want us to believe it’s reliance on logic and empirical evidence without allowing oneself to be influenced by emotion. What’s more, being rational is what somehow allows certain characters (Data, Seven of Nine, House, Bones) to see the world as it really is.

I’m not so sure I buy this, and here’s why. Logic is a syntactical framework: it’s not a set of beliefs in itself*, it’s a bunch of rules that tell you how beliefs relate to one another in truth-preserving ways. Contrary to Mr. Spock, without any other information, it’s just as logical to believe that showing emotion is a good thing as it is to believe showing emotion is a bad thing. What makes one of these conclusions illogical isn’t logic on its own but logic in combination with the other beliefs a person happens to hold.

For instance, suppose I believe that showing emotion prevents the otherwise inevitable repression of feelings, and that repression of feelings is unhealthy. Then (presuming I don’t want to be unhealthy), it’s logical for me not to suppress my emotions. Contrariwise, if I believe that not showing emotion prevents me from feeling emotions, and that feeling emotions is undesirable in a good scientist, then (presuming I want to be a good scientist), it’s logical for me to keep my feelings under wraps.

Because the conclusions derived from use of logic depend so heavily on the user’s previous beliefs, it’s difficult to argue that logic on its own is enough to give you an accurate picture of the world. So it seems like plain reliance on logic and empiricism can’t be what we mean by being rational.

But does being rational have to mean having an accurate picture of the world? I don’t think so. Suppose you and I are in a room, and there are two boxes in front of us: a red one and a blue one. I’ve been told by the people in charge, whom neither of us have any reason to distrust, that the red box contains a million dollars and the blue box contains poisonous snakes. You’ve been told that the blue box is the one with the cash and the red box is filled with herpetological death. Furthermore, these boxes are made of such solid material that there’s no way for us to tell from the outside what they might hold – so there is no empirical evidence that might make either of us doubt our assumptions.

Now, presuming we both would rather have a million dollars than die of a snakebite, if we get to choose separately, we’re each going to open different boxes. That means one of us is choosing the box with the snakes in it.

Normally, opening a box with venomous snakes inside seems like an action only an irrational person would take. But opening a box with venomous snakes inside because you think it’s full of money and the other one’s the deadly one doesn’t seem irrational at all. In fact, if I truly believed that the red box contains a million dollars and the blue one death, it seems like I’d be irrational not to choose red, even if it happens to be the case that it actually contains twenty angry cobras.

(On an unrelated note, do you know how hard it is to figure out new and interesting ways to repeat the concept “deadly snakes”?)

So being rational seems to have something to do with a person’s beliefs about the world, not the actual state of the universe around them. It also seems to have something to do with a person’s goals. If you for some strange reason really want to be bitten to death by snakes right now, it makes sense for you to open a deadly-snake-filled box, even though the very same action would be utterly irrational on the part of someone who really wants to survive the next ten minutes.

True, people often talk as though goals themselves can be rational or irrational, but it seems more like a shorthand for “you won’t be able to achieve this goal in the time frame you’ve set out” or “this goal conflicts with something else I know you want”. Only people can be rational or irrational.

It sounds like I’m getting further from a TV understanding of rational and closer to the quantitative version: in classical economics, a rational person is one whose decisions are based on the utility of an outcome (i.e. how much they think they want it) and its probability (i.e. how strongly they believe it will happen). According to classical economics, you can assign precise numbers to each of these things – getting a puppy might have a utility of exactly 103 for me, and I might think it’s got a 23.919% chance of occurring if I whine and beg my parents on my next birthday.

I’m not sure that it makes sense to quantify beliefs and desires to such a fine degree. But I do think the economic model brings out an important feature: the point of economic analysis isn’t to define what it means to be rational and hold everyone’s behaviour up to a certain standard**, it’s to try to describe and predict the existing behaviour of groups of individuals.

In other words, rather than looking at someone opening a snake-filled box and saying, “That doesn’t conform with our definition, so that person must be irrational”, it’s looking at a lot of people opening snake-filled boxes and saying, “OK, let’s assume these people are behaving rationally. How can we explain what’s happening here?”

For a classical, possibly straw-man economist, rationality is something we can assume groups of individuals have. Picking out one particular person and deciding whether they’re rational or irrational is comparing their behaviour to a sample group and seeing how it measures up.

This underscores what I think is one of the most pertinent things about rationality: even though it’s purportedly a mental trait, and it seems to be based on things inside people’s heads, when it comes to making cases of specific individuals, the best we can do is look at what they do and compare it to what someone else, whom we’ve already decided is rational, does. Often, because we’re human, that “already rational” person is ourselves.

If I were delusional, or mentally ill, or under the influence of mind-expanding substances, most people would want to say I’m irrational. And I think what they’d mean by it, when you get right down to it, is that there’s something so strange about my beliefs, my goals, my logic, or any combination of the three that my behaviour defies your understanding.

Likewise, when one TV detective says to another, “You’re being irrational about this! You want Mrs. Smith to be innocent, so you’re ignoring the evidence!”, what that really seems to mean is, “I think you should want to find the truth more than you want to be emotionally comfortable, and so I don’t understand why your priorities seem to be the reverse.”

It seems to me that at its very base, being rational is about going after what you want most using the best information about the world that you have. Obviously, this oversimplifying in the sense that people often want multiple, contradictory things, at the same time, and you often can’t pinpoint which you want most at any given moment.

Maybe fictional characters who are supposed to be rational like the ones I mentioned at the beginning of this blog are all logical and “scientific” precisely because those kinds of reasoning are easy for other people to follow. As viewers, we’re usually privileged to see the “true” fictional state of affairs, and we can generally assume the camera is giving us an objective view of what’s really going on in the Star Trek or Bones universe. So it’s hard for us to follow the view of a character who doesn’t see all this.

Maybe Seven and House and Spock aren’t necessarily rational because they’re meant to be logical, but logical because they’re meant to be rational.

* Except beliefs about logic, but let’s not get into that.

** Yes, sometimes some people use it that way, but that’s not its ultimate purpose.