Although causation necessarily implies correlation, correlation does not imply causation. — Mr Bee

One use of the concept, though, is to help us weed out spurious correlations. — Srap Tasmaner

In my work and in my play I have occasion to do many regressions - statistical analyses of the association between observed phenomena. In that context, for many years I have preached the gospel of 'correlation does not imply causation' and pointed to regressions that identify strong relationships between tea sales in Germany and rates of divorce in Canada as evidence of the difference.

What has changed in me is not that I think that there's no difference between useful correlations and spurious ones. It's that I think 'causality' is the wrong razor to use to make the distinction.

The most obvious reason for that is that a razor is - the etymology declaims it - something sharp, accurate, defined with excruciating precision. We have seen in this thread that nobody wants to define causality, and it has even been suggested that it's a mistake to try to do so. That's fine, but without a definition we cannot use it as a razor. We need a different concept - a clear, precise, well-defined one - to distinguish between spurious and non-spurious correlations.

My current thinking is that a good candidate for that razor is the persistency of the correlation under different circumstances. That is what I was trying to elucidate with the pharmaceutical example. Most spurious correlations will disappear if we can conduct the experiment under different circumstances.

An even better razor is if we can identify a mechanism that enables us to predict that if B occurs, C is likely to follow. We can't always do that, so we have to fall back on the first razor. Sometimes we can't even use that, so we remain in a state of ignorance as to whether the correlation is spurious or persistent. But we keep trying.

There's nothing illogical about saying 'the cause of your fever is that you have influenza'. It's just that I see it as an imprecise, slang statement that's great for everyday life but doesn't fit well in philosophy, or in law courts or other arguments about whose fault it was. Its meaning is usually something like 'you have influenza, and in the process of working through one's influenza, one usually develops a fever.' The latter statement has a precision that the former does not. If more detail is wanted, one can describe how the immune system typically reacts to its detection of the influenza virus, the rapid increase in the activity of T cells and white cells, the battles that take place in the blood stream, and so on. It's all about mechanism.

Another point - God I prattle on, don't I? The use of the word 'cause' as a substitute for mechanism seems to depend haphazardly on the history of the discipline. In physics we talk about 'light cones of causality' even though they are better described as 'light cones of predictability'.

Against that is the example of Credit Risk Analysis - the discipline of predicting how many borrowers are likely to default on (fail to repay) their debts. Poor credit risk analysis was a major factor in the global economic disaster that started in 2008 and whose effects are still being felt. In this field there are two types of mathematical models used to predict probability of default. They are called Statistical and Structural models respectively. Statistical models, as the name suggests, look solely at the characteristics of borrowers and do regressions to work out which characteristics are correlated with default. Structural models focus on the financial structure of the company - its assets and liabilities - and the movements of stock price indices and use an economic model to predict which companies are likely to default, based on the observation that default occurs when one's liabilities exceed one's assets. This type of model looks at what some would loosely describe as 'cause' of default whereas Statistical models do not. But interestingly, the word 'cause' is barely mentioned in the literature. The word 'Structural' is used instead, which has a natural similarity with Mechanism.

This is good stuff, Andrew. It's good to hear the thoughts of someone in the data trenches. I have a few more questions though.

I think there was a bit of special pleading in the influenza example. There's a "usually" thrown in with the predictive version that the causal version doesn't have. Surely the user of causal talk could be just as modest.

That "usually" made me wonder if we shouldn't try to separate the unpredictability of what we're talking about from the imperfection of our understanding of it. I had wanted to say there's a difference between saying, "Influenza is usually accompanied by fever, but we have no idea why," and saying, " Influenza is usually accompanied by fever, because [details]." But the "usually" itself could mean, "We don't know why it happens sometimes but not others," or it could mean, "There is some randomness to the way this process works, such that [details]." It seems worthwhile to keep those separate.

I just keep thinking that once you've given up this one big distinction, at least as an ideal to strive for, that all sorts of other meaningful distinctions will fall away too. I really like distinctions.

It seems like you are saying that we should do away with the concept of causation altogether, but I thought your point was that there was no distinction between cause and correlation? If you're saying that causation is correlation then that's one thing, but if you were just saying that causality is a mistaken concept to begin with then that's something else entirely.

Also, the kind of correlation that I gave in my earlier example (of two symptoms of an illness) isn't exactly spurious as it certainly implies a deeper relation that isn't coincidental and is thus in that sense useful. However, my point was that relation wasn't one of causality, where one causes the other to happen. Instead, we would say that they both are related in sharing a common cause. They can be related, but not in the same way that, say, a brick thrown at a window is related to its being broken.

I am not sure how you plan to distinguish between both cases, or if you even intend on doing so, but it doesn't seem like persistency is a good enough way of doing so. The symptoms of an illness are usually found to be tightly correlated in many cases, as is healing when a chemical is ingested. But that doesn't mean we should treat both cases the same way.

if you were just saying that causality is a mistaken concept to begin with then that's something else entirely.

It's closer to that than the other. But saying it's a 'mistaken' concept is a bit too strong. I see 'cause' as a vague term that can be perfectly safely used in cases where its vagueness does not present problems - which is in many areas of everyday life.

IMHO the 'mistake' is to take that vague term and then try to use it in areas where clarity is necessary - like philosophy, science, law and arguments over fault. There are much clearer and more precise terms available, as discussed above, and I am advocating their use in those contexts, rather than 'cause'.

I see 'cause' as a vague term — andrewk

Yes, but 'cause' has at least two precise senses which I don't believe can be done away with in "philosophy, science, law.." etc; to do so would be to lose. not to gain, clarity (not to mention most of our explanations). The first is efficient causation; the action of a physical force, and the second is formal or final causation; agents acting for reasons. Are you really claiming that the concept of efficient forces can be done away with in science, or that the notion of agents acting for reasons could be dispensed with in the humanities?

Are you really claiming that the concept of efficient forces can be done away with in science, or that the notion of agents acting for reasons could be dispensed with in the humanities? — John

References to efficient causes are absent from most science I have read, and the parts where authors have referred to them would, IMHO, be better off without those references. The product of scientific endeavour is theories and equations, which give rise to explanations and predictions.

I'm not so concerned about 'final cause', and certainly wouldn't want anybody in the humanities to have to change their patterns of speech. My concern in this discussion is about precision and logic, and I see the humanities as being about emotions rather than about precision and logic. If somebody can write better poems or novels by using the word 'cause' then that's great. I might make an exception for history though, as that is a bit like science in some ways. I find discussions such as 'what was the cause of the Great War' profoundly mistaken. I don't mind so much if they ask 'describe some causes of the Great War' although personally I prefer the talk to be about enabling conditions.

So, no mechanical forces are understood to operate in geology? Physical science doesn't posit four fundamental forces? Animals are not understood to be subject to climate and topography, and the forces and conditions attendant upon those?

Also, I don't understand what you mean when you say that the " humanities are about emotion rather than precision and logic". Are you saying there is no logic of human emotion? That logic and emotion are entirely separate and unrelated?

Of course the causes of any complex social (or antisocial) phenomenon such as the Great War are multifarious. Is there a cogent conceptual difference between a "cause" and an "enabling condition" in the context of history? Surely conditions that lead to events in the human sphere just are the causes of those events, no?

References to efficient causes are absent from most science I have read, and the parts where authors have referred to them would, IMHO, be better off without those references. The product of scientific endeavour is theories and equations, which give rise to explanations and predictions. — andrewk

This seems to be a somewhat physics-centric view of "science" (a not-uncommon view in discussing the philosophy of science - sometimes fields other than physics are referred to as the "special sciences." Some might thus be reminded of Dana Carvey's Church Lady character from SNL...but I digress).

Science as a whole has not dispensed with the notion of cause. Epidemiologists speak of the cause(s) of disease outbreaks, paleontologists speak of the cause(s) of mass extinctions, etc. I also don't think that every science concerns itself with equations or predictions (though all are theory-laden, certainly). Some scientific fields are largely qualitative, and are largely retrodictive, as opposed to predictive, in nature (the aforementioned field of paleontology likewise applies here).

For a quick-and-dirty illustration of my point, a search for "caus*" restricted to titles alone in the public medical literature database at PubMed.gov yields 255,563 hits. The same search performed at arXiv.org yields too many hits to be displayed, maxing out at 1,000 hits.

So, no mechanical forces are understood to operate in geology? Physical science doesn't posit four fundamental forces? Animals are not understood to be subject to climate and topography, and the forces and conditions attendant upon those? — John

I'm afraid I don't understand these rhetorical questions, but they sound interesting. Can you explain them, and how they relate to the discussion?

I'm afraid I don't understand these rhetorical questions, but they sound interesting. Can you explain them, and how they relate to the discussion? — andrewk

For example, isn't gravity posited as the cause of planetary orbits, black holes, the rate of objects falling, etc?

If our universe lacked the force of gravity, then none of those things would be the case. If there was no electromagnetic force, then there would be no molecules. You might wish to think of the fundamental forces in terms of their theories and how they explain things, but I don't know how you do away with causal aspect. Part of explaining how matter attracts is that gravity is the cause of matter attracting.

I don't mind so much if they ask 'describe some causes of the Great War' although personally I prefer the talk to be about enabling conditions. — andrewk

Let's say I enable conditions for you to rob a bank. I give you a weapon, a getaway vehicle, code to the safe, and the best time to commit the robbery, and whatever encouragement I think you need.

That doesn't mean you will go through with it. Enabling conditions aren't enough to determine whether you commit the crime.

You know, mechanical forces otherwise known as efficient causation, for example, the movement of tectonic plates causes uplift, water and wind are efficient causes of erosion. Climate and topography cause unique opportunities for, and constraints upon, plant and animal life, micro-organisms cause decay and so on. There are countless examples of the idea of efficient causation in science; in fact the notion is pretty much constitutive of the conceptual models that science consists in. The cycle of nature is understood to be a vast network of interacting forces, mechanical, chemical, electrical, building up and breaking down bodies at all scales; all this just understood to be.efficient causation.

Enabling conditions aren't enough to determine whether you commit the crime. — Marchesk

Yes indeed. And the same applies to the things to which people typically apply the term 'cause'. Hence I think 'enabling condition' is a better term - suitably modest.

You might wish to think of the fundamental forces in terms of their theories and how they explain things, but I don't know how you do away with causal aspect. — Marchesk

My position is that any attempt to use the word 'cause' must relate to a theory. This viewpoint is explained in detail in this essay I wrote a few years ago. That position has shifted a bit since then, and this discussion has helped that - given me new insights. But I still hold the central idea that reference to a 'cause' without specifying the theory to which it relates is as meaningless as the word 'here' when we don't know where the speaker is.

There are countless examples of the idea of efficient causation in science; in fact the notion is pretty much constitutive of the conceptual models that science consists in. — John

People interpret the theories as being about 'efficient causation'. That is not the same as the theories themselves containing propositions about efficient causation. It is very common for people to mistake the interpretations of scientific theories for the theories themselves. This is particularly prevalent - and comes into particularly sharp focus - in quantum mechanics. But it happens with other theories as well.

— John

People interpret the theories as being about 'efficient causation'. That is not the same as the theories themselves containing propositions about efficient causation. It is very common for people to mistake the interpretations of scientific theories for the theories themselves. This is particularly prevalent - and comes into particularly sharp focus - in quantum mechanics. But it happens with other theories as well. — andrewk

I would say it's not merely a matter of interpretation. Science is all about explaining why things happen; it's all about explaining the mechanisms of action and interaction that drive changes. Science asks why things happen the way they do and it answers " Because..."

Scientific theories do not contain propositions about efficient causation, because that would be the province of philosophy or metaphysics. But all scientific theories do contain propositions that embody notions of efficient causation. This seems undeniable to me. Perhaps you could give an example of a scientific theory (apart from QM) that does not comply with this condition.

But all scientific theories do contain propositions that embody notions of efficient causation. — John

It is the interpretation that asserts that embodiment, not the theory. In its purest form, the theory is a bunch of equations.

There's nothing wrong with inserting words like 'because' into a presentation of a scientific theory, but it is purely optional. As I said above, an explanation is a deduction that starts from premises that the explainee understands and believes, proceeds by steps the explainee understands and believes, and reaches a conclusion that is a prediction of the occurrence of the phenomenon for which the explainee had requested an explanation.

I see 'cause' as a vague term that can be perfectly safely used in cases where its vagueness does not present problems - which is in many areas of everyday life. — andrewk

Yes, "cause" is a vague term, but that is principally because it has many different senses, and it is used ambiguously. In philosophy this ambiguity is a invitation to equivocation.

Some philosophers like Aristotle's writing about causes. I find them akin to his writing about physics. For me, Aristotle is brilliant on ethics and logic, and the rest is of purely historical interest, like phlogiston. — andrewk

I don't think you should be so quick to dismiss Aristotle's clarification of the four ways in which "cause" was used. Though it appears in his "Physics", it is a logical work, clarifying the distinct ways in which the word was used, in an attempt to avoid the ambiguity referred to above. It was necessary to get this clarification over with prior proceeding with physics. There were actually six ways that "cause" was used, presented by Aristotle. The final two were "chance" and "fortune", which he dismissed as not proper use of the word, leaving us with the familiar four. Of the four, common usage over time has shied away from "material cause" and "formal cause", such that we do not use "cause" in these two ways any more. This leaves us with "efficient cause", and "final cause" as the two principal ways in which cause is used. So the ambiguity with the term is generally between these two distinct ways.

I'm not so concerned about 'final cause', and certainly wouldn't want anybody in the humanities to have to change their patterns of speech. — andrewk

You should be concerned with final cause though, because this is where the term "cause" is useful. As you explain, we can do science without "efficient cause", because we use concepts such as explanation and prediction. "Efficient cause" seems to require a certain logical necessity which cannot be logically validated. But "final cause" is based in the determination of a different type of necessity, we determine what is needed (necessary) to produce the desired end. The end itself is therefore of the highest order of necessity, validating the need for the means. When the end, that which is wanted, or desired, is determined, then what is needed to bring about that end can be determined, and this is "caused" to come into existence, by an act of willing. So the act of willing is a cause, in the sense of final cause. And as much as we can refer to prediction to explain the fact that we determine the means to the end through the use of prediction, we cannot explain the fact that the end is desired, and that we cause the existence of the means, for the sake of the end, by referring to prediction.

So let's go back to Pneumenon's example, of creating letters on the screen by hitting the keys. Hitting the keys is a means to an end. It is therefore an intentional act of willing. Assuming that we have fully dealt with the ambiguity between different ways of using "cause", why do you think that we should not use "cause" to refer to how intentional acts create things?

It is the interpretation that asserts that embodiment, not the theory. In its purest form, the theory is a bunch of equations.

There's nothing wrong with inserting words like 'because' into a presentation of a scientific theory, but it is purely optional. As I said above, an explanation is a deduction that starts from premises that the explainee understands and believes, proceeds by steps the explainee understands and believes, and reaches a conclusion that is a prediction of the occurrence of the phenomenon for which the explainee had requested an explanation. — andrewk

'Theory' is a polysemous term with different applications in different contexts. You are adverting to the notion of 'theory' relevant to QM, which is a special case. In most other sciences and in the humanities, theories just are explanations, not mathematical models. Mathematical models may help support such theories but the substance of them consists in explanations in ideas expressed in ordinary, even if sometimes more or less technical, language.

Your definition of an explanation is incorrect, as I see it, because it conflates what the explanation is trying to do (which is to give the reasons why something is as it is) for what would support the verity of the explanation (which is what we think we would expect to observe if the explanation were true).

I seems that to give reasons for why anything is as it is is always to give an explanation in terms of causes. If you disagree then why not give an example of an explanation of any phenomenon which is not couched in terms of causality?

"Efficient cause" seems to require a certain logical necessity which cannot be logically validated. — Metaphysician Undercover

This is not true. Take the hammer and nail example. If striking the nail with the hammer is the efficient cause of driving the nail, that entails no necessity that the hammer striking the nail with sufficient accuracy logically must result in it being driven, or even that its being driven is physically necessary . If QM indeterminism is true, then the driving of the nail is merely probablistic. It might be expected to happen a quadrillion times a quadrillion times; but there is always the vanishingly tiny chance that it might not be driven, that the hammer might pass through the nail, for example.

why not give an example of an explanation of any phenomenon which is not couched in terms of causality? — John

Newton wonders 'why does the apple fall from the tree?'.

He comes up with his gravity theory that there is a gravitational force F on the apple, whose magnitude is given by the gravity equation. He also comes up with his law of motion that F=ma. Putting the two equations together, he deduces that the apple will accelerate towards the centre of the Earth with initial acceleration GM/r^2.

There is no use of the word 'cause', or any synonym thereof, anywhere in that explanation.

A philosopher may listen to the explanation and say 'Aha! So the cause of the apple's fall is the force of gravity'. But that is the philosopher's interpretation of the explanation, not the explanation.

I haven't seen it put the way you put it before. It sounds like you are saying that Aristotle's aim was to distinguish the different ways in which people used (the ancient Greek equivalent of) the word 'cause'. If so, then maybe I have been too hard on him. I don't know how Ancient Greeks used words. He's likely to know much more about that than me. Also, even though there will be big differences between how they used a word and how we use its modern equivalent, I think I see some similarities between the uses he describes and the modern uses.

I don't see people around me using 'cause' in the sense of his 'final cause' though. Maybe it's just the society in which I live, but people I know just don't use the word 'cause' that way. I have no reason to suspect that Ancient Greeks didn't though. The closest I have observed is that people will use the word 'because' to explain why they did something. But I find the similarity between 'because' and 'cause' purely textual, not semantic.

In summary, if the main thrust of the 'cause' discussion is about final cause rather than efficient cause, maybe Aristotle and I are not at variance after all.

Isn't the obvious modern correlate of "final cause" "purpose"?

'Purpose' raises more dilemmas too. I have yet to work out whether finding a 'purpose' for one's life is the same as finding a 'meaning' of one's life. I tend to think that the only sensible way we can interpret 'meaning of life' is as 'my purpose in life', but I think there are many that disagree with that.

There is no use of the word 'cause', or any synonym thereof, anywhere in that explanation. — andrewk

He comes up with his gravity theory that there is a gravitational force F on the apple, — andrewk

Newton postulates the application of a force which affects the apple, and produces its acceleration; its acceleration is the effect of the force. The idea of an affecting or effectual force, a force which produces an effect, just is the idea of an efficient cause. Nothing you have said presents anything at all convincing to the contrary, as far as I can see. To be honest I still have no idea what your proclaimed objection consists in.

You appear to be asserting, without any detectable supporting argument, that somehow 'cause' is an inextricable part of the explanation, even though the explanation does not mention 'cause'. I do not accept that assertion.

That you are unconvinced is an observation on which I thought we had already agreed.

Again, this is incorrect; what I am asserting is that the ideas of cause, and the ideas of force and influence are essentially the same. Are you saying that the force of gravity does not cause the apple to accelerate? I understand that you might object that I could simply say that the force accelerates the apple; but the idea of a force influencing a body just is the idea of efficient causation; the latter is its general formulation, and covers all cases of different kinds of forces affecting different kinds of bodies differently. It is precisely the idea of efficient forces in play that distinguishes causation from mere correlation.

Isn't the obvious modern correlate of "final cause" "purpose"? — Srap Tasmaner

Seems right to me. The final cause of a heartbeat is to create blood pressure. Final cause answers: for what? It's pervasively used in biology.

Are you saying that the force of gravity does not cause the apple to accelerate? — John

No. That would be a use of the word 'cause'. When being careful, I generally avoid uses of the word 'cause' (as opposed to references to the word, of which I have made two so far in this post) because it does not have a clear definition and, in my opinion, leads to confusion.

I neither accept nor deny what is in the quote above, but rather suggest that it is not a well-formed proposition, because the word 'cause' does not have a clear meaning in this context. Fortunately for me, 'Gravity causes the apple to accelerate' is a sentence that I cannot recall having ever seen anybody utter, except on a philosophy forum.

By the way, I wonder about your notion of 'explanation', that an explanation is an identification of a 'cause'. If so then it seems you use the word 'explanation' very differently from how those around me do. Under such a notion, explanations would be very short, consisting solely of a reference to the phenomenon that the explainer considers to be the 'cause'.

Q. Why does the apple fall? A. Gravity
Q. Why is the sky blue? A. Refraction
Q. Why do people with mostly African ancestors have darker skin on average than people with mostly European ancestors? A. Evolution (or Melanin, or Vitamin D deficiency, or Skin cancer - it's hard to know which one to pick)

In my experience, explanations are much longer than this. The explanations I have received, and have given, have been narratives, not mere references. The narrative (which as I have said, has the formal structure of a deduction that starts from premises that the explainee understands and believes, and proceeds by steps that the explainee understands and believes) will usually refer to many different phenomena along the way, with none of them distinguished from the others and having the special label 'cause' affixed to it.

I think if the explanations I had given my children when they asked about things had been like the examples given above, they would have been quite frustrated.

Q. Why does the apple fall? A. Gravity
Q. Why is the sky blue? A. Refraction
Q. Why do people with African heritage have darker skin on average than people of European heritage? A. Evolution (or Melanin, or Vitamin D deficiency, or Skin cancer - it's hard to know which one to pick) — andrewk

What do all those explanations have in common? It seems to me that all you are doing is producing one word explanation which are not grammatical sentences because they tendentiously avoid using the words 'caused by' or 'because' , which are nonetheless there implicitly.

What if I asked you what relation gravity has to an apple falling, or what relation refraction has to the blue sky? How would you explain those relations without referring to the influence of forces or materials (efficient causation)?

You suggest that darker skin might have come about in African peoples due to selection pressures that occurred due to deaths attendant upon lighter skins in earlier times. Do you really want to claim that 'cause of death' is somehow a confused or incoherent notion? Those deaths were not caused by lighter skins. Although they were correlated with lighter skins, lighter skins were merely a condition that required exposure to the sun to produce melanomas, that resulted in early deaths (given that the theory is correct).

It is just the same as the hammer and nail example; there are all sorts of conditions; the existence of humans to wield hammers, the existence of hammers and nails, the existence of materials soft enough such that nails could penetrate them, and materials hard enough to work as hammers and nails and so on. And yet we have very good reasons to believe that no nail has ever been driven without being struck by a hammer or some suitable substitute.

You misread@andrewk's last post. Those were examples of "here's the cause" explanations, not the sort of explanation he was advocating.

This is not true. Take the hammer and nail example. If striking the nail with the hammer is the efficient cause of driving the nail, that entails no necessity that the hammer striking the nail with sufficient accuracy logically must result in it being driven, or even that its being driven is physically necessary . — John

The necessity is found in the relationship between the cause and the effect. In order to say that striking with the hammer was the cause of the nail being driven, we assume a necessary relation between the two, such that it is impossible that anything else caused the nail to be driven. That a nail could be driven by something else, or that the hammer might strike the nail and fail to drive it, is irrelevant to the case in which the striking of the hammer is said to be the cause of the nail being driven. In this latter case, in which the striking of the hammer is said to be the cause, there is assumed a necessary relation between the striking with the hammer, and the driving of the nail.