Reading Time: 9 minutes Chad Davis, flickr,, CC 2.0
Reading Time: 9 minutes

You could be mistaken for thinking that this post was about free will. It can be, but I am more concerned with the general idea of causality in the context of Derek Chauvin’s court case to decide whether the death of George Floyd was homicide or not.

Chad Davis, flickr,, CC 2.0

Let me first introduce you to or remind you of the philosopher JL Mackie and his INUS conditions of causality. He was interested in what was taking place when effects had a plurality of causes. Let us take the effect X and look at A, B and C as contributory causes of X. He coined the acronym INUS, which stands for these causes being insufficient but nonredundant parts of an unnecessary but sufficient condition for X. Now imagine that X is a house fire. There was a short-circuit that took place in the wiring that calls this. However, the gas was also left on. The short-circuit would not have caused the fire on its own as it required both the gas and an abundance of flammable material for the fire to take place. This scenario was not a necessary condition either as the fire could have been started in a number of other ways, such as with an arsonist and a Molotov cocktail.

When we ask the question, what caused the fire, we are met with a real head-scratcher because all of these causes contributed to the fire taking place and removing one of them, whether it is a short-circuits, the gas all the flammable material, would have meant that the fire would not have taken place. As Mackie stated himself:

(ABC or DGH or JKL)’ represents a condition which is both necessary and sufficient for P: each conjunction, such as ‘ABC’, represents a condition which is sufficient but not necessary for P. Besides, ABC is a minimal sufficient condition: none of its conjuncts is redundant: no part of it, such as AB, is itself sufficient for P. But each single factor, such as A, is neither a necessary nor a sufficient condition for P. Yet it is clearly related to P in an important way: it is an insufficient but non-redundant part of an unnecessary but sufficient condition: it will be convenient to call this…an inus condition.

Mackie, 1974: 62

Let me bring into play a quote from my book Did God Create the Universe from Nothing? Countering William Lane Craig’s Kalam Cosmological Argument [UK], were look at the notion of causality and show that it is difficult to untangle it even though we know that causality (in whatever way we might define it) is taking place:

…let us look at causality and the problems with it. Let me analogise to make the point as clear as possible.

Smith is driving along the road over the speed limit. He is tired due to a heavy work schedule and a deadline which meant a lack of sleep the night before and is late for a meeting. One of his favourite songs comes on the radio and he starts singing along to it. On the pavement (sidewalk) a drunk man falls over into a bin which the Borough Council had just put in place to improve the cleanliness of the town. The bin is knocked off its stand and rolls into the road. Smith sees the bin late as his attention is distracted. He swerves, to avoid it. At the same time, a boy is trying to cross the road without looking. Smith is swerving into him and has to reverse his swerve significantly the other way, hitting a pothole in the poorly maintained road. This sends the car out of his control and onto the pavement. Jones, who had been walking by, slips on some soapy water draining from the carwash he is walking past. Whilst Jones is picking himself up, Smith’s car mounts the pavement, hits Jones, and kills him instantly. What is the cause of Jones’ death?

This is a very difficult, but standard causal question. The universe is not an isolation of one cause and one effect. It is a matrix of cause and effect with each effect being causal further down in something like the continuum. One could say that the impact of the car on Jones’ head kills him. But even then, at what nanosecond of impact, what degree of the force killed him? This is arbitrarily cutting off the causal continuum at 1, half or quarter of a second before the effect (Jones’ death). Having said that, the cause could be said to be the lack of oxygen to the brain, or the destruction of his vital organs. We could also accuse the bin, the drunk or anything else as being a cause, because without each of these, the final effect would not have taken place.

As a result, I would posit that the cause of Jones’ death is one long continuum which cannot be arbitrarily sliced up temporally. As such, it stretches back to, say, the Big Bang—the start of the causal chain. In terms of free will, we call this the causal circumstance. Because the universe is one big causal soup, I would claim that any effect would be the makeup of the universe at any one point, like a snapshot. This makeup that leads to any given effect cannot be sliced up arbitrarily but is the entire connected matrix of ‘causes and effect’ (for want of a better term) since the Big Bang.

In other words, there is only one cause. The universe at the Big Bang (or similar).

If I am picking up a cup of tea to drink from it now, then we could just look at a few seconds before this as to the cause. Perhaps it was just my intention. But how about the notion that my parents introduced me to tea, and all those instances of tea drinking which came from that that now enforce my intentions? What if tea had not evolved? What if my grandparents had not given birth to my parents, and them to me? What if humanity had not evolved? What if the Earth had not harboured life? Without all of these, I would not have picked up my cup of tea. They are all relevant (and all the bits in between, and connecting them to other parts of the matrix) to my drinking tea now.

Philosopher Daniel Dennett uses another example about the French Foreign Legion that he himself adapted from elsewhere to illustrate problems with a basic notion of causality, of A simplistically causing B:

Not that deadlocks must always be breakable. We ought to look with equanimity on the prospect that sometimes circumstances will fail to pinpoint a single “real cause” of an event, no matter how hard we seek. A case in point is the classic law school riddle:

Everybody in the French Foreign Legion outpost hates Fred, and wants him dead. During the night before Fred’s trek across the desert, Tom poisons the water in his canteen. Then, Dick, not knowing of Tom’s intervention, pours out the (poisoned) water and replaces it with sand. Finally, Harry comes along and pokes holes in the canteen, so that the “water” will slowly run out. Later, Fred awakens and sets out on his trek, provisioned with his canteen. Too late he finds his canteen is nearly empty, but besides, what remains is sand, not water, not even poisoned water. Fred dies of thirst. Who caused his death?

This thought experiment defends the thesis that causality is, at times, impossible to untangle or define. I would take this one very large step further in saying that the causality of such an effect, of any effect, is traceable back to the first cause itself: the Big Bang or whatever creation event you ascribe to.

Causality is a very tough thing to precisely decipher. Indeed, the safest explanation for any given is the entire universe at the most proximal instant before the given effect. Better still, the universe at t5 is caused by the universe at t4.

What does this mean for the causal responsibility (and notice here I am this differentiating causal responsibility from moral responsibility) of any given person in any given action that they carry out?

Trying to extricate a single cause out of the matrix of causes is impossible. However, this is what the legal system (that we have in every country in the world) does. For some background reading on my views of moral responsibility:

Let us transfer this causal issue onto the case of Derek Chauvin.

We have a situation where a policeman knelt on someone’s neck for 9 1/2 minutes. Adding to the causal mix from Floyd’s unique body and biological status, including the fact that he had a heart condition and drugs in his bloodstream.

The questions then become:

  • Would he have died in the same situation but without, say, his heart condition the drugs in his body?
  • How necessary were the contributory factors to his death?
  • Would the same kneeling have caused the next person to have died, who didn’t have a heart condition and drugs in their system? But then, how do you define “the next person”?
  • Do you take an average of all people?
  • Would you use an exemplar who was perfectly healthy and that’s your representation of a human for legal purposes?
  • Is it right that this representative is someone who is perfectly healthy all the time?
  • At what line of demarcation does something that is a contributory factor exonerate someone who is also a contributory factor?
  • So on and so forth.
In terms, there is something that seeks to answer at least some of these questions and it is called “the eggshell rule” or “the thin skull rule”:

The eggshell rule (also thin skull rule or talem qualem rule)[1] is a well-established legal doctrine in common law, used in some tort law systems,[2] with a similar doctrine applicable to criminal law. The rule states that, in a tort case, the unexpected frailty of the injured person is not a valid defense to the seriousness of any injury caused to them.

This rule holds that a tortfeasor is liable for all consequences resulting from their tortious (usually negligent) activities leading to an injury to another person, even if the victim suffers an unusually high level of damage (e.g. due to a pre-existing vulnerability or medical condition).[3] The eggshell skull rule takes into account the physical, social, and economic attributes of the plaintiff which might make them more susceptible to injury.[4] It may also take into account the family and cultural environment.[5] The term implies that if a person had a skull as delicate as that of the shell of an egg, and a tortfeasor who was unaware of the condition injured that person’s head, causing the skull unexpectedly to break, the defendant would be held liable for all damages resulting from the wrongful contact, even if the tortfeasor did not intend to cause such a severe injury.

In criminal law, the general maxim is that the defendant must “take their victims as they find them”, as echoed in the judgment of Lord Justice Lawton in R v. Blaue (1975), in which the defendant was held responsible for killing his victim, despite his contention that her refusal of a blood transfusion constituted an intervening act.[6]

The doctrine is applied in all areas of torts – intentional tortsnegligence, and strict liability cases – as well as in criminal law. There is no requirement of physical contact with the victim – if a trespasser‘s wrongful presence on the victim’s property so terrifies the victim that he has a fatal heart attack, the trespasser will be liable for the damages stemming from his original tort.[citation needed] The foundation for this rule is based primarily on policy grounds. The courts do not want the defendant or accused to rely on the victim’s own vulnerability to avoid liability.

The thin skull rule is not to be confused with the related crumbling skull rule in which the plaintiff suffers from a detrimental position (from a prior injury, for instance) pre-existent to the occurrence of the present tort. In the “crumbling skull” rule, the prior condition is only to be considered with respect to distinguishing it from any new injury arising from the present tort – as a means of apportioning damages in such a way that the defendant would not be liable for placing the plaintiff in a better position than they were in prior to the present tort.[7]

Things are further confused when we are trying to second guess the intention that may or may not lie behind what Chauvin did. In simple terms, we say that had Chauvin not knelt on Floyd’s neck, Floyd would not have died. But, we could also say that had these other conditions not been present, as the defence would argue, Floyd would not have died, either. So do all the other conditions fall under the eggshell rule? How important is the intention of Derek Chauvin? Can the prosecution definitely show that A.N. Other person would have died given the same amount of neck kneeling? Is this important given that what Chauvin did was not standard training and procedure anyway?

The defence will be strenuously accentuating the causal importance of the extenuating circumstances and factors in Floyd’s death, and the prosecution will be strenuously accentuating the causal importance of Chauvin’s ridiculously long-lasting kneel. How the jury will evaluate these positions will be interesting to see, and there will be no shortage of cultural implications attached to the verdict.

My opinion is that the police officer’s actions were morally reprehensible and action should be taken with regard to this (in appropriate ways, see links below), charging him within the scope of the law; but proving this simplistic account that Chauvin caused the death of Floyd is a very difficult thing to do with the kind of singularity of factors and clarity people are looking for. For a start, a clearly defined understanding of “caused” needs (and perhaps has?) to be agreed upon. I simply don’t think that our legal frameworks are set up to allow for such nuance and, well, accuracy.



J.L. Mackie. 1974. The Cement of the Universe: A Study of Causation. Oxford: Clarendon Press.

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Jonathan MS Pearce

A TIPPLING PHILOSOPHER Jonathan MS Pearce is a philosopher, author, columnist, and public speaker with an interest in writing about almost anything, from skepticism to science, politics, and morality,...