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"I didn't turn them on" is a fact. It's the "because" that's not a fact. The whole point of the article is that you can't get causality from things that didn't happen. There are seven billion other people in the world who also didn't turn on the lights. What makes your inaction special?

In order to get the "because" we have to imagine another state of the world where you DID turn on the lights, and further speculate that this would have been effective to illuminate the room. That's counterfactual, because the fact is that it's dark in here.




But the because is not about imagining another state of the world, it's about using logic.

If me turning on the light is a necessary condition for the light being on, then it implies that if I did not turn on the light the light is off. There is no speculation. This is also what distinguishes this one "counterfactual" from all the others.

The article seems to completely ignore that we can readily argue about negative statements. I highly doubt that airplane crash investigators would avoid counterfactuals.


There are no necessary conditions in the physical world. If you hadn't turned on the light, perhaps someone else would have. Or perhaps a bird or a meteorite could have flown through the window and struck the switch in just such a way as to turn it on. Or perhaps a wire could have come loose inside the switch and fallen in just such a way as to close the circuit.


Sure there are necessary conditions in the real world. It is a necessary condition for the apple to hang on the tree, for it to fall from the tree onto Newton's head.

By arguing there are no necessary conditions you are essentially saying we can't use mathematics to describe nature and there are no laws of physics.


For the apple to fall on Newton's head? It could have been dropped by a passing swallow (or possibly two, held on a line between the dorsal guiding feathers).

For it to fall from the tree? Well, that's a linguistic trick; for it to fall from the tree it must have been hanging on the tree, so that necessary condition is actually a tautology.

Physics describes a world with statistical regularities, not absolute laws. Even a clockwork Newtonian universe is not time-reversible; it has multiple pasts that can lead to the observed present.


It's not a tautology to say for an apple to fall of a tree it has to be on a tree, it's not a tautology for a plane to crash to be flying first or for a car to stop it needs to be in motion first. They are all necessary conditions, in fact this is the definition of a necessary condition.

Something to be a necessary condition has nothing to do with time-reversibility, it simply states a logical relationship

Let me give you another example: To accelerate a body with mass m it is necessary to exert a force onto it. All mathematical descriptions In fact equivalency, requires conditions to be necessary and sufficient.

Your argument that physics describes a world with statistical regularities is a maybe a nice philosophy, however most physicists (and regular people) do not believe we live in a simulation, but physical laws describe the real world.


Regarding Newtonian universe. Is that really true, that multiple pasts can exist? Some source would be very welcome.


Yes; a simple example is Norton's dome. It is possible to construct a frictionless curve such that a particle that is pushed up the curve with correct initial velocity will reach the top and halt in finite time. Observing a particle sitting at the top of the dome, there is no way to tell when it reached that point or from which direction.


It's not that "multiple pasts can exist", it's that "multiple pasts _would be sufficient to explain_ the effect that is being observed now".

E. g. "The apple hit Newton on the head" could be explained by:

1. The apple was hanging on the tree at `t - 1` and the wind shook it loose.

2. The apple was flying through the air because his mother threw it and it collided with his head

3. The apple spontaneously generated due to as-yet-not-understood quantum fluctuations 3 meters above his head.


I think it is hard to answer this without reducing the real world into something it may not be. What constitutes an event in the real world? Is the universe discrete or continuous? Do we really use mathematics to describe nature, or do we use it to model and approximate some properties of it?


I think the article doesn't say that the counterfactuals are not useful, it explicitly mentions they can be used as recommendations, as in "do not forget to monitor your disk space".

What they say is that counterfactuals stop the search for the root cause. Not monitoring disk space isn't a root cause of the filled disk. The root cause might be "application has suddenly written too many logs". This gives another set of counterfactuals, like "if your application was configured properly, it would write less logs". But it also gives an option of continuing the search for the root cause, which might be, for example, "there is a bug in the application which triggered the log writes".

I think the point of methods like 5 whys is not to stop at the first set of counterfactuals and deepen the search.


Let's take a different example, the plane crashed because the landing gear did not retract. This is a counterfactual according to the article, do you really believe it stops us for looking at the root cause for why the landing gear didn't retract? In fact, I don't think we would be able to even investigate the root cause if we hadn't first identified the cause of the landing gear not retracting.


I think your example is not a counterfactual, because in your world, landing gear actually didn't retract. Remember, whether something is counterfactual or not depends on what the facts are.

Had the landing gear been retracted in your hypothetical world, then it would be a counterfactual, but it probably wouldn't arise because it's not something out of ordinary - the landing gear retracting is a usual procedure. I think humans are more prone to make the mistake that is described in the article (stopping to search for the root cause) when they see a counterfactual conditional which premise is, in the factual, a procedural error (for example, "operator failed to monitor the disk space"). We see an error and mistake it for the root cause.


If me turning on the light is a necessary condition for the light being on, then it implies that if I did not turn on the light the light is off.

To be pedantic, it’s not quite that either. The logic theorem states if A => B then !B => !A. The => means that A is sufficient for B, because “false => true” evaluates to “true” but “true => false” evaluates to “false”. If it were “necessary”, those statements would evaluate the opposite way.

This means that if me turning on the lights is sufficient for the light being on, then the light being off is sufficient to deduce that I did not turn it on.


I don't think you're contradicting my post.

You are simply stating that me turning on the light is not a necessary condition, but a sufficient condition (which is a reasonable argument).

My argument was that if the statement "if the light is on it was turned on by me" is true (i.e. the me turning on is a necessary condition), then if I did not turn on the light the light is off [edited after mistyping before].

I think this works better with other examples, because as you state, we typically think more of the turning on as a sufficient condition.


I don't think you're contradicting my post.

Yes, it wasn’t my intent to contradict your overall point, just to correct your logic.

My argument was that if the statement "if the light is on it was turned on by me" is true (i.e. the me turning on is a necessary condition) then it follows that if the light is off, I have not turned it on.

I disagree with you here. The counterfactual, or at least the logic theorem, for the statement [light is on] => [I turned the light on] (me turning it on is necessary for it to be on) is [I did not turn the light on] => [the light is not on]

That’s sound, though it’s not a particularly insightful leap of logic.

If you translate this to the author’s point, they’re basically saying that !A => !B doesn’t tell you that A => B. And that’s correct as far as Boolean logic goes. I am unclear on whether we disagree on that point.


Sorry I edited my post just after posting it, because I realised I wrote it the wrong way around (too many nots and light switches ;). You managed to reply just in between.

>I disagree with you here. The counterfactual, or at least the logic theorem, for the statement [light is on] => [I turned the light on] (me turning it on is necessary for it to be on) is [I did not turn the light on] => [the light is not on]

Yes you're correct and that's what I corrected my statement to where you managed your reply in between.

However my original statement was:

>If me turning on the light is a necessary condition for the light being on, then it implies that if I did not turn on the light the light is off.

so A=>B therefore !B=>!A. Where A == "light is on", and B == "me turning light on". I agree that it's not particularly insightful.

My point was regarding the statement "The whole point of the article is that you can't get causality from things that didn't happen" from the OP I replied to. That's just not true, we can make statements about causality for things that didn't happen, because we can deduce them from logical conditions.

>If you translate this to the author’s point, they’re basically saying that !A => !B doesn’t tell you that A => B. And that’s correct as far as Boolean logic goes. I am unclear on whether we disagree on that point.

Although we agree in principle I disagree what you say is the authors point.

From the article: >They [counterfactuals] express wishful thinking about an alternate history where the bad event didn’t happen. Because they represent “events that didn’t occur” they cannot have caused anything.

This is a statement I disagree with. To me that sounds that the author essentially says we can not make statements of the type of !A => B (or !B). To me that is wrong and also not a counterfactual. Counterfactuals, are statements about a hypothetical event, i.e. "If I had not turned the light on it would be off now". To me though the author seems to extend the definition of counterfactuals to mean "events that did not happen", maybe he means the correct thing, but both his words and examples do not reflect the correct meaning IMO


How would you determine that it's a necessary condition and not just a sufficient condition?


Are you saying that "If I had turned on the lights, they would be on" wouldn't be a true statement?

It seems like it would be strange to reject as an answer to "why do blind people tend spend less on lighting?" with "Because they don't tend to use the lighting, because the lighting isn't useful to them, so they don't turn the lights on as much (unless someone else who isn't blind is there).".

How else would you answer that question? (modulo little wording changes and such)


It's tautologically true, in that you used the word "on" in both clauses, and "if on, then on" is always true.

But no, in a meaningful sense it's not a true statement about the world. It's a good guess, and for a statement that simple, there might be no need to go further. For a statement about why a volume is full with too many files, the point is that a nice-sounding "if only" isn't something you can test or be certain of.

Your answer about blind people is a very good guess as well, and the same one I would make, but it's not data.


I actually meant to present that as: Because I didn't flip the switch.

A counterfactual requires posing a situation with changed facts. I stand by my statement, saying "X because not Y" is not a counterfactual on its own. "not Y" is still a (potentially) factual statement. And guesses still aren't counterfactuals. "Maybe the lights aren't on because we didn't flip the switch?" That's a hypothesis, and a testable one. Still not a counterfactual. If we know the flip hasn't been switched, then it's just a fact even if the statement is in the form of not X.


The counterfactual is "if I had flipped the switch, the lights would be on." That is a situation with changed facts, and therefore counterfactual. The tricky bit is the causality. We have to construct an alternate history, with a counterfactual cause and a counterfactual result. And we can't actually know that. Maybe the bulb is burnt out. Maybe there's a power outage just now. Maybe we've blown a fuse. The causality is just conjecture.

Now consider the opposite. The lights are off because the bulb burnt out. That's a lot less ambiguous. If you want to doubt the causality you've got to get all mystical.




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