Can you think of any earlier moment in history in which you would prefer to live your life? One’s initial reaction may be to answer yes. The thought of living in Renaissance Florence or Samuel Johnson’s London or Paris inLa Belle Époque is seductive. But then comes the catch: In whatever era you choose, your station in life will be determined by lottery, according to the distribution of well-being at that time—which means that in Renaissance Florence you are probably going to be poor, work hard at a menial job, and find an early grave.

Wherever I go, whether my audience consists of local students, congressional staffers, or post-Soviet professors, when I present the TROLLEY case and ask them whether they would switch tracks, most will say, “There has to be another way!” A philosophy professor’s first reaction to this is to say, “Please, stay on topic. I’m trying to illustrate a point here! To see the point, you need to decide what to do when there is no other way.” When I said this to my class of post-Soviet professors, though, they spoke briefly among themselves, then two of them quietly said (as others nodded in agreement), “Yes, we understand. We have heard this before. All our lives we were told the few must be sacrificed for the sake of many. We were told there is no other way. But what we were told was a lie. There was always another way.

A ubiquitous feature of philosophical practice is to consult intuitions about merely conceivable cases. Imaginary examples are treated with the same respect and importance as real examples. Cases from the actual world do not have superior evidential power as compared with hypothetical cases. How is this compatible with the notion that the target of philosophical inquiry is the composition of natural phenomena? If philosophers were really investigating what Kornblith specifies, would they treat conceivable and actual examples on a par? Scientists do nothing of the sort. They devote great time and labor into investigating actual-world objects; they construct expensive equipment to perform their investigations. If the job could be done as well by consulting intuitions about imaginary examples, why bother with all this expensive equipment and labor-intensive experiments? Evidently, unless philosophers are either grossly deluded or have magical shortcut that has eluded scientists (neither of which is plausible), their philosophical inquiries must have a different type of target or subject-matter.

[Tesla’s] mental constructs were built with meticulous care as concerned size, strength, design and material; and they were tested mentally, he maintained, by having them run for weeks—after which time he would examine them thoroughly for signs of wear. Here was a most unusual mind being utilized in a most unusual way. If he at any time built a “mental machine,” his memory ever afterward retained all of the details, even to the finest dimensions.

I finished my doctoral dissertation when I was very young, at about the age of twenty-three. I thought I wanted to direct my philosophical work to questions that I really cared to answer. This is going to sound strange because one assumes that one will work on things that one cares to answer, but there are a lot of intellectually intriguing questions in philosophy: puzzles, paradoxes, little things that one can think about, especially in the Anglo-American analytic tradition, which were there for their own sake. I had a little imaginary experiment I haven’t thought about since then: if I were working on certain topics for two years, and if I were in an automobile accident that caused me to be in a coma, and then, when I came out of the coma, was told that somebody had solved this problem, but that it had been done in such a difficult way that I would have to spend a year of my life trying to understand the solution, would I still be interested in it?

In approaching the problem of incontinence it is a good idea to dwell on the cases where morality simply doesn’t enter the picture as one of the contestants for our favour—or if it does, it is on the wrong side. Then we shall not succumb to the temptation to reduce incontinence to such special cases as being overcome by the beast in us, or of failing to heed the call of duty, or of succumbing to temptation.

Thought experiments are not supposed to be realistic. They are supposed to clarify our thinking about reality.