Philosophers often incur derisive sniggers at the idea that they can figure out the world “without leaving their armchair!” In some respects, I agree with that criticism. The idea of being able to reason a priori about the finitude of the universe or the existence of a god is pretty absurd.
But there is one tool in the philosophical toolkit that I absolutely believe allows you to learn about the world from the comfort of your favorite armchair: the thought experiment. In a regular experiment, you intervene in the world in some way, observe the results, and make an inference from those results about how the world works. Thought experiments use that same template, but the “data” you’re observing is the output of your own brain, and you use it to make inferences about the workings of a very specific part of the world: you.
This is one of the most useful tools I know for introspecting about my own motivations, values, emotional reactions, and preferences. I’ll start with a simple example, to illustrate the idea. Let’s say I’m considering applying to graduate school, but I’m reluctant, and I want to have more insight into the reasons for my reluctance. I might tell myself that it’s because I believe it wouldn’t be worth the time and difficulty, and that I didn’t expect to find a good enough job upon graduation to make that investment worth it. But I also suspect that I might be loath to apply because I’m afraid of getting rejected. How can I test which factor is really motivating me?
Well, what I would do in that case is hone in on one variable that I hypothesize might be important — e.g., my fear of rejection — try varying it, and observe how that changes my outcome variable (motivation to apply to grad school). There are plenty of ways I could vary “fear of rejection.” For example, I could imagine myself applying and knowing, somehow, that I would get in to all the schools to which I applied. That’s not very realistic, though. It’s hard to convincingly imagine something that would never happen in real life, and in real life, we can’t just “know” what’s going to happen ahead of time with certainty. It’s much better, when possible, to make your thought experiments believable so that your reactions to them constitute reliable data.
So instead, the thought experiment I would do in that case is to ask myself: “Imagine that your top choice grad school department invited you to come visit, and after interviewing with the professors there, they were so impressed with you that the head of the department told you flat-out: We want you here and we’re just going to skip the admission process with you. Let us know by tomorrow if you want to join our program.” Would I, in that scenario, still feel hesitant about going to grad school? If so, that result gives a lot of credence to the hypothesis that my hesitation stems from doubts about whether grad school is a worthwhile investment for me. If not, that result gives more credence to the hypothesis that my hesitation stems from a fear of rejection.
Here’s a related example of using thought experiments to figure out my own motivations. Once I was in graduate school, I had to figure out whether I really wanted to be a professor. I had a few hypotheses about my motivations, but to keep things simple, let’s focus on two. Hypothesis 1: I want to be a professor because I predict that I will really enjoy research and teaching. Hypothesis 2: I want to be a professor because it’s prestigious and I like the idea of having a prestigious job.
What kind of thought experiment could I do to test Hypothesis 2? As in the last experiment, there are many ways I could vary the “prestige” variable. I could say, “Imagine being a professor wasn’t prestigious...” But that’s the kind of change that’s hard to imagine. (In general, thought experiments of the sort “Imagine that our world was different in the following way(s)...” produce less reliable data than those that begin, “Imagine that tomorrow, X happens...” In other words, counterfactuals are harder to imagine than likely future changes.)
So the thought experiment I did instead was to ask myself: “Imagine that you’re offered a job that allows you to do all the research and/or teaching you want, but it’s not officially a professorship. It’s... I don’t know, let’s say, a ‘Lecturer’ position or something else that doesn’t sound very prestigious. In other words, you’re not allowed to call yourself a professor. Now how much do you want the job?” And if my answer is “Eh, not much,” then that suggests Hypothesis 2 was on the mark.
In addition to investigating your motivations, you can also use thought experiments to investigate your emotional reactions to people or situations. For example, I was once planning a potential vacation but feeling kind of blah about it when I envisioned myself on the trip. But was that “blah” reaction an accurate simulation of how much I would enjoy the trip once I was on it? Or might it be that I was just tired or in a funk for some other reason and therefore unable to imagine myself having fun? The thought experiment I did in this case is somewhat different: I imagined myself doing something that I knew, from repeated past experience, I always enjoyed (a friend’s annual Halloween bash). The result: I couldn’t imagine myself enjoying that either. Which indicated to me that the original hypothesis (“I can’t simulate myself enjoying this trip because this trip isn’t the sort of thing I would enjoy”) was probably false, and that the true hypothesis was more likely to be: “I can’t simulate myself enjoying this trip because my simulation module is temporarily broken.”
I’ll close with one more example of investigating your emotional reactions with thought experiments. A while back my roommate offered me a cookie from the box she had just bought. I felt a (mild, fleeting) pulse of irritation at her offer, because I was on a diet and she knew it — wasn’t it insensitive of her to offer me something she knew I wasn’t allowed to eat? At least, that was the explanation my brain gave me for why I felt irritated. Then I did a thought experiment: what if she had not offered me the cookie? How would I have reacted then? To my surprise and amusement, when I simulated that scenario, I still felt mildly irritated: “Is she not offering me a cookie because she knows I’m on a diet? Huh, that seems kind of paternalistic of her. Can’t she let me make my own choices about what I eat??” The fact that I would have felt irritation no matter how my roommate had handled that situation indicates that the irritation had more to do with the situation itself (want cookies, can’t have ‘em) than with anything my roommate did.
Next time: Using thought experiments to explore your values.