Ah, I must disagree on some of this! Counterfactuals are essential to the work of actual history. We imply them all the time, whenever we talk about causality. If I say, "the Civil War was caused by slavery," then I am implying, to one degree or another, that if slavery hadn't existed, the Civil War wouldn't have happened. If I say, "Adolf Hitler was an important man," I'm implying history would have been different if he had winked out of existence while only a bad landscape painter. There is no sin in this — it is just how causality works.

Historians also love contingency. We love to show that things didn't have to be the way they were, that nothing was set in stone, that history isn't just a jumble of predictable forces but a lot of other things as well. We can't do that if we decide counterfactuals are a waste of time.

I would contend that the historian who rejects counterfactuals is actually in self-denial about their use of them. And of their value, but that's a separate issue.

In the hands of someone who is serious about history, a counterfactual can be illuminating. We are not talking about Harry Turtledove here. We are talking about nice, focused questions whose answers do not overstate their authoritativeness (for they are not) and are used to excavate aspects of the past that might not be obvious from the narrative of what did happen.

An example of mine that I like quite a bit: If Albert Einstein had never existed, would the atomic bomb have been invented during World War II? This superficially seems like a silly question to ask. But it's not. It's really a question about the specific importance of a historical figure (Einstein) and his work (relativity) towards the specific historical creation of nuclear weapons at a specific moment in history (World War II). In this sense it is actually quite focused.

Now one could answer this poorly, to be sure. The average person thinks Einstein's role was very important in the making of the bomb — E=mc^2 and the Einstein letter to Roosevelt are often given pride of place in the stories of the bomb. But this erroneous understanding is exactly what this question can help correct. It would not be controversial amongst historians of physics to assert that by 1939, the mass-energy relationship would probably have already been discovered via an alternative route (it is not so clever as many of the other aspects of Einstein's work, and in any case Einstein was more a creature of his era than we tend to acknowledge today, doing work that was not so different than the work of others at the time). (Historians of science generally do not ascribe to a model of "genius" that says that "without so-and-so, this idea would never have come about" — in some cases we can actually tell you who the candidate was for independent discovery, because they were working along exactly the same lines as the other person, and missed out by the smallest of margins.) And separately, the importance of the mass-energy equivalence with regards to the specific phenomena of nuclear fission is overstated, and the latter was not anything like a direct consequence of the former line of inquiry. This is a different scientific genealogy of the atomic bomb than the popular mind often has — it is a product of research into particle physics, not relativity.

And one can do similar things for the Einstein letter, etc. By pointing out why Einstein was not as important as we might think, we have an opportunity to point out what was important. The counterfactual has given us a nice "frame" to think through causality in history. This is not just a rhetorical device: this is because we are engaging explicitly with causality when we talk about counterfactuals, and not allowing ourselves to be sucked into the implicit causality of "what happened."

The problem with counterfactuals, of course, is that some are far too broad to be answered. What would global society look like today if World War II hadn't happened? Too broad — there are so many factors that would be modified if you took that big variable out of the equation. That doesn't mean you couldn't point to some of those factors (e.g., would decolonization have sped up or slowed down without the war?). But there is such a soup of them that it is difficult to even start to answer sensibly.

Second, to answer them well you really have to know your stuff, and you have to be aware of where you are really diverging from the script and where you are not. You have to couch everything in the language of uncertainty, to be sure. And the goal of the answer has to be to point out plausible roads not taken, not to give a definitive and authoritative answer of what would have happened. But just because the latter isn't possible, doesn't mean the questions — or their answers — can't be valuable and generative.

So I dispute that "what if" is just a game. It's much more than that! And real historians play it all the time, even if they aren't conscious that they are doing so. I don't think we need to be hard-ass about it here unless it gets very much out of control in terms of bad answers. But why regulate the questions themselves on this? Unless there is really a swamp of them, I don't think it's a dangerous thing to allow.

Real historians ask questions like this all the time, as do students, as do interested laymen. The problem with the Harry Turtledove style isn't the questions he asks, it's that the answers he gives aren't really meant to be history, they're meant to be elaborate works of fiction. But there are other approaches — don't throw out babies with our bathwater, unless the babies are really stinking up the tub.

Great question, Sally. "Counterfactual" comes from the Middle English word "counter," meaning "in opposition to" or "against" and the word "factual," meaning "factual."

Middle English? That's it? Nothing from Latin contra, or facere?

The erasure of Latin from English continues apace, I see. The barbarians have won.

On the flip side, bringing up alternate plans is highly important - any discussion around the use of atomic weapons in Japan is put into context by the estimates around the invasion and the fact the Japanese had more men and material in theatre than any Allied estimates.

Geschichtswissenschlopff ─ "unhistorical shit."

I love this sub. And apparently I love British historian Edward Palmer Thompson.