Thursday, April 21, 2016

Chance: the modern witchcraft

"Thus, however 'mystical' the content of Zande witchcraft beliefs may or may not be... they are actually employed by the Zande in a way anything but mysterious -- as an elaboration and defense of the truth claims of colloquial reason. Behind all these reflections upon stubbed toes, botched pots, and sour stomachs lies a tissue of commonsense notions the Zande apparently regarded as being true on their face: that minor cuts normally heal rapidly; that stones render baked clay liable to cracking... that in walking about Zandeland is unwise to daydream, for the place is full of stumps. And it is as part of this tissue of common sense assumptions, not of some primitive metaphysics, that the concept of witchcraft takes on its meaning and has its force... It is when ordinary expectations fail to hold, when the Zande man-in-the-field is confronted with anomalies or contradictions, that the cry of witchcraft goes up. It is, in this respect at least, a kind of dummy variable in the system of commonsense thought. Rather than transcending that thought, it reinforces it by adding to it an all-purpose idea which acts to reassure the Zande that their fund of commonplaces is, momentary appearances to the contrary notwithstanding, dependable and adequate." -- Clifford Geertz, "Common Sense as a Cultural System," Local Knowledge, pp. 78-79

Contemplating this passage, I was struck by how "chance" plays the same role in the common-sense world of someone from the modern West as witchcraft plays for the Zande. We expect people who smoke to come down with lung cancer; when someone who is never smoked in their life does so, what do we say caused it? Chance! We expect Stephen Curry to shoot 46% on his three point attempts; when he goes 1-for-12, what is to blame? Chance! We expect someone who drives skillfully and carefully to avoid accidents; when they have one anyway, it was... Chance that did it.

In fact, "chance" is not an actual cause of anything at all.* It is the name we give our ignorance of the actual cause of an event. Consider a coin toss: the coin will come up heads or tails not by "chance," but due to exactly how it was flipped, how the air influenced its motion, the balance of the coin, and so on. But we lack the ability to follow exactly how all of these factors will influence the outcome; we call our ignorance "chance."

So, just as witchcraft serves as a dummy variable for the Zande in their common-sense world, chance serves as a dummy variable in ours. Other cultures have chosen "the will of God," or "Fate," or "Kismet," as their name for this dummy variable. We prefer chance as our "all-purpose idea" because, given that we can give the notion a mathematical formulation, it allows us to believe that we are still being good scientific rationalists when when we stuff Silly Putty into the cracks in our understanding of the world.

* Yes, I am aware of quantum uncertainty; a discussion of that topic is beyond the scope of this post, and irrelevant, since our common invocation of chance does not involve matters such as when an electron will fall into a lower orbital!


  1. But, the Zande belief in witchcraft entail additional conclusions, right? I mean, if I am the victim of witchcraft, then someone has done witchcraft against me, and then it is very reasonable for me to imagine who might be to blame and then blame them, potentially taking action against them. For any of the other options, "chance" or "fate" or "the will of God", there is no one to blame except perhaps God.

    I agree very much that "chance" is not an explanation, but a profession of ignorance. Therefore, it's a perfectly valid concept as long as I don't get confused and think it's an explanation. This makes it a better dummy variable than witchcraft, because witchcraft goes beyond dummy variable in implying facts about the world.

    1. I only know about the Zande third-hand, through Geert describing Evans-Pritchard's findings. But at least in that description, I haven't seen any descriptions of having to "find the witch."

      But, as noted, I am pretty ignorant here!

  2. Well some of us prefer chance as our “all-purpose idea” - the foundational logic of our science - not because we are trying to stuff Silly Putty into the cracks in our understanding of the world but because we recognise that it (necessarily) has cracks and that doing otherwise would be irrational.

    Quantum mechanics, at least when it's rationally interpreted, is simply the natural extension of probability theory applied to noncommuting 'observables'. And perhaps it is beyond the scope of the post but in some ways it's even easier to see via QM why probabilistic reasoning is necessary and should be regarded as fundamental. See e.g. Max Born's Nobel lecture.

    1. I am not talking about the use of probability in science: my post is explicitly about the world of common sense.

    2. " I was struck by how "chance" plays the same role in the common-sense world of someone from the modern West"

      "The common-sense world," not the world of science!


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