Causality, Counterfactuals, and Possible Worlds

Source: xkcd

“A Causal Revolution has spread like a chain of firecrackers from one discipline to the next: epidemiology, psychology, genetics, ecology, climate science, and so on... With every passing year I see a greater and greater willingness among scientists to speak and write about causes and effects, not with apologies and downcast eyes but with confidence and assertiveness.”
- Judea Pearl, "The Book of Why" (2018)

"Philosophy begins in wonder."
- Socrates

The pursuit of a better future for ourselves and our children begins with asking "Can we do better?" and furthermore, "Could we have done better, had we acted differently?" To both these questions, we must answer in the affirmative. That being the case, I believe we cannot avoid following up with "Why?" According to Judea Pearl, the prototypical "Why?" question is actually a counterfactual question in disguise.

People often imagine how things might have turned out differently "if only." But can counterfactual claims be true? Neil Sinhababu said this question about "possible worlds" is one of the hardest problems in philosophy. Nonetheless, "counterfacutal history," not to be confused with "alternative history" or "historical revisionism" (which has separate popular and academic meanings) can yeild important insights. For example, consider that following the election of President Trump, a lot of people who were disappointed in this outcome were asking "Why?" If Bernie Sanders had won the 2016 presidential primary, would Trump have been elected? If James Comey had not announced his investigation into Hillary's emails just 11 days before the election, would Trump still have won? Of course, we all know that such counterfactual scenarios did not occur, but it's hard not to wonder how things might have turned out differently.

Or consider that in the course of WWII, Alan Turing played a pivotal role in cracking intercepted coded messages that enabled the Allies to defeat the Nazis in many crucial engagements. Counterfactual history is difficult with respect to the effect Ultra intelligence had on the length of the war, but at the upper end it has been estimated that this work shortened the war in Europe by more than two years and saved over fourteen million lives.

A useful analogy is that counterfactual research in history is like chess. Each new move opens up the possibility for roughly thirty-eight times as many positions in the branching tree of analysis. We can ask: What are the most promising "moves?" How might the interaction of these counterfactuals and existing context play out? What is the logic connecting antecedent and consequent and the assumptions on which chains of causation are based? Supercomputers are routinely used to conduct counterfactual simulations in the sciences, where there can be multiple interactions at every move, and the chains set in motion interact with one another simultaneously and continually. (Richard Ned Lebow, "Counterfactual thought experiments: A necessary teaching tool")

Isaiah Berlin (Virtual History by Niall Ferguson)

Another great opportunity to ask some important "what if?" questions is suggested by Hanna Rosin, the author of "The End of Men: And The Rise of Women," where she chronicles the economic and cultural shifts that are upending male dominance. In a recent interview she said "Every time you have forward motion economically, any kind of progress for women, it's accompanied by a giant tidal wave of cultural backlash. And that's exactly the moment we're in right now." So let's ask: What if male dominance is upended? Ensuring women can enjoy the same rights and privileges as men is essential to our future. And yes, that will affect many cultural institutions, including marriage and child-rearing practices. Can we find a healthier response to this forward motion than the socially damaging cultural backlash we see now?

Would a better understanding of social physics and especially cause-and-effect relationships lead to the development of a Fair Society (as outlined in Peter Corning's book of the same name)? Consequentialist ethical theories posit that the consequences of actions should be the primary focus, so it would seem obvious that a clearer view of how cause and effect operates, at both very small and very large scales of space and time, could have significant ethical implications. If Judea Pearl is right when he claims a "causal revolution" has begun, this knowledge may force us to choose whether we will squarely face the ethical dilemmas that confront us, or renege on our responsibility to act given what we know. If we choose the later, our inaction will be rationalized away using the psychological acrobatics of self deception. But if we choose confrontation, it will be because our cumulative cultural evolution is open-ended and able to advance in spite of our individual limitations.

Visions of a better future, whether utopian or merely incremental, always address social problems, and, after the start of the Industrial Revolution these invariably include environmental problems as well. In so doing, we assume the ability to diagnosis our problems and prescribe an appropriate course of treatment. This descriptive/prescriptive dynamic is either explicit or implied. In this light, the fear of an apocalyptic dystopia is just as often the fear of human incompetence in diagnosis and treatment, as often as it is the fear of truly malign forces at work. This should serve to underscore the importance of understanding causal processes.

Our ability to gather information about the world around us, inquire how causal relationships change, and to intervene so we can change our behavior patterns, is critical. None of the answers to a question contain the possibility of asking the question in the first place, as my former philosophy professor, Dr. Benesch, was fond of saying. Scenarios that consider "what if?" questions are useful for both the possibilities and the insights they suggest, but they cannot simply suggest themselves. This is why the ability to ask the "what if?" and "why?" questions is so important. We need more counterfactual thinking today more than at any time in our past. The causal revolution hasn't arrived a moment too late.

Postscript:

Sewall Wright

The possibility of asking questions seems to assume subjective awareness, which seems to assume time asymmetry and therefore causality. If our subjective experience of time was symmetrical (no arrow of time) then the explanatory tool of causation, and the concepts of free will, agency, and intervention would likely be incomprehensible. But because we cannot see the future, the concept of causation is our primary tool to help bring it into focus. Causality is therefore the means, and understanding is the goal. Hence, if some procedure other than causality were discovered that could provide a greater means for understanding the interaction among variable factors across spatial and temporal scales, then that would be used in its place. As Newtonian physics is to general relativity, perhaps causation is to this as yet undiscovered means.

A few unresolved problems remain for me: 1) in the presence of synergistic effects, it may be impossible to perform meaningful causal analysis, and 2) depending on deterministic factors, we may need to reconceptualize our notion of how change occurs - intervention may only be described completely as a property of an entire system, not any single agent within that system.

"Causal inference may be superfluous in some idealised, superhuman version of physics, but if you actually want to find out how the Universe works, it is vital. ...But this doesn’t mean we must believe in a richly metaphysical idea of causal powers, ‘producing’ or ‘bringing about’ causal regularities like muscular enforcers of the laws of nature. We still see only the patterns, the constant conjunctions of different sorts of event."
- Mathias Frisch

But I can't neglect to mention the relationship between causality and feedback (cybernetics), and how that in turn relates to social networks and Alex Pentland's hope to have a transformative impact on our understanding of the dynamics of human society and our ability to plan for the future. And after all, causality and teleonomy may both be inherent biological qualities:

"Cognition is heavily grounded in space. As animals that move in space, we travel both physically and mentally in space and time, reliving past events, imagining future ones, and even constructing imaginary scenarios that play out in stories. Mental exploration of space is extraordinarily flexible, allowing us to zoom, adopt different vantage points, mentally rotate, and attach objects and sense impressions to create events, whether remembered, planned, or simply invented."
- Michael Corballis, "Space, time, and language"

My former history professor, Dr. Cole, identified the importance of looking to the future without being held in the past, a specific reference to The Pattern Problem. “In one sense, I feel sorry for younger people today because they’re trapped by the inability to reinvent themselves, free of the burdens of the past. People who know the past are stuck in it because they love repeating it,” Cole said. “This may sound odd to you, coming from a history professor, but I think history is a trap for many people.” ...You can escape that trap with counterfactual thinking.

Sourced quotes: 

"The ability to reflect on one's past actions and envision alternative scenarios is the basis of free will and social responsibility. Counterfactuals are at the core of the cognitive advances that made us human and the imaginative abilities that have made science possible. ...The rewards of having a causal model that can answer counterfactual questions are immense. Finding out why a blunder occurred allows us to take the right corrective measures in the future. ...The advantage we gained from imagining counterfactuals was the same then as it is today: flexibility, the ability to reflect on and improve upon past actions and, perhaps even more significant, our willingness to take responsibility for past and current actions."
- Judea Pearl, "The Book of Why" (2018)

"The survival of the fittest is a slow method for measuring advantages. The experimenter, by the exercise of intelligence, should be able to speed it up. ...If he can trace a cause for some weakness he can probably think of the kind of mutation which will improve it."
- Alan Turing, “Computing Machinery and Intelligence”(1950)

"We may define a cause to be... if the first object had not been, the second never had existed."
- David Hume (1748)

"Evolutionary events weren't destined to occur in the way that they did..."
- Stephen Jay Gould (1989)