and the “not quite” might result in some lawyer, or even some judge, who ought to, but doesn’t, know better concluding that the “not quite” means that the result of the trial is wrong in law.
Consider these statements of law from a recent trial decision. I haven’t quoted the case but, if you’re reading this online, and believe it necessary to know the case name, you likely know how to find it.
The onus the plaintiff bears is to establish that “but for” the Accident she would not have sustained her headaches, that is, that the conduct of the defendant caused or contributed to …. : Clements v. Clements, 2012 SCC 32 (CanLII), 2012 SCC 32.
The onus on the plaintiff to establish her claim requires proof on the balance of probabilities: that it is more likely than not that her headaches were caused or contributed to by the Accident. Causation need not be proved with scientific precision and may, in certain circumstances be inferred from the evidence using ordinary common sense: Athey v. Leonati, 1996 CanLII 183 (SCC),  3 S.C.R. 458 at paras. 16 – 17.
What did the trial judge mean by “contributed”? Does “contributed” mean something other than “cause” in the sense that “cause” is used in Clements in para. 8: necessary for the occurrence of?
 The test for showing causation is the “but for” test. The plaintiff must show on a balance of probabilities that “but for” the defendant’s negligent act, the injury would not have occurred. Inherent in the phrase “but for” is the requirement that the defendant’s negligence was necessary to bring about the injury ― in other words that the injury would not have occurred without the defendant’s negligence. This is a factual inquiry. If the plaintiff does not establish this on a balance of probabilities, having regard to all the evidence, her action against the defendant fails.
If not, what did the trial judge mean by “contributed”. Something other than what Clements means? Almost certainly not; however, if not, where did the trial judge get the “or contributed” from? Not from Clements, itself.
I suspect I can provide an explanation which satisfies the necessity meaning, but that’s a guess. If you want to know what the guess is, look at para. 17 of Athey and the first sentence. But that’s still the conception of necessity that’s the core of but-for cause as explained by Clements. It’s not some different concept of the meaning of “causation” that amounts to “contributed” rather than “caused”.
On the third hand, I suppose that, at this point, I’ve become much like Cassandra, yet the the sky hasn’t fallen – yes, I’m thoroughly mixing references. So, what if I point to a reference or two from the province immediately east of the one in which I now reside and work? And the most recent SCC case on point included in the Alberta case, which just happens to be a case that started in the province in which I now, etc. It’s Dehekker v Anderson-Penno, 2014 ABQB 95. The trial judge wrote:
 Recently, in Ediger v Johnston, 2013 SCC 18 (CanLII), 2013 SCC 18, the Supreme Court reaffirmed the legal test for causation and stated at paras 28-29:
This Court recently summarized the legal test for causation in Clements v. Clements, 2012 SCC 32,  2 S.C.R. 181. Causation is assessed using the “but for” test: Clements, at paras. 8 and 13; Resurfice Corp. v. Hanke, 2007 SCC 7,  1 S.C.R. 333, at paras. 21-22. That is, the plaintiff must show on a balance of probabilities that “but for” the defendant’s negligent act, the injury would not have occurred: Clements, at para. 8. “Inherent in the phrase ‘but for’ is the requirement that the defendant’s negligence was necessary to bring about the injury — in other words that the injury would not have occurred without the defendant’s negligence” (ibid. (emphasis deleted)).
Does this call for a Simpsonian “D’oh”?
While I realize that I’m likely (a bit) unusual (outside of the academic realm) in keeping track of what’s been written about Clements, regardless of how easy CanLII makes that, isn’t it “common sense” (whatever else common sense might mean) to expect that the judge and lawyers in the case from which I took the 2 paragraphs that are the reason for this screed – certainly the judge who writes the reasons: regardless of what he or she was told by counsel in submissions – to use the “nice” (in the old sense) summary of Clements in Ediger? At the least, that would avoid carping from me. After all, if judges (and lawyers) know about Ediger in Alberta, even Ontario and Quebec, is there a good reason for forgetting in B.C.?
Now let’s move to the phrase “ordinary common sense”. Yes, it’s in Athey, at para. 16, but it’s in a quotation from Snell which Snell lifted from a House of Lord’s decision which people should read before quoting from: ” as Lord Salmon stated in Alphacell Ltd. v. Woodward,  2 All E.R. 475, at p. 490, and as was quoted by Sopinka J. at p. 328, it is ‘essentially a practical question of fact which can best be answered by ordinary common sense’.”
Lord Salmon never explained what “ordinary” common sense means as opposed to any other type of “common sense”. Clements doesn’t use the word “ordinary”.
Any number of well regarded academics have pointed out the meaningless of the common sense cant.
What does Clements say? Isn’t Clements where one should now look for the meaning of all aspects of the but-for test? Unless, of course, they’re not dealt with.
Clements stated, at para. 9: ” The ‘but for’ causation test must be applied in a robust common sense fashion.”; in para. 20, that in Snell “‘t]his Court affirmed recovery, but on the basis of a robust and common sense application of the “but for” test.”; at para. 23, that in Athey “Major J. emphasized that a robust common sense approach to the “but for” test” …; in para. 28: “Snell, Athey, Walker Estate and Resurfice were all resolved on a robust and common sense application of the “but for” test of causation.”; in para. 38, which contains the point made in the last sentence of the 2nd passage of quoted from the trial decision:
 “Scientific impossibility”, relied on by the trial judge in this case, is merely a variant of factual impossibility and attracts the same objections. In many cases of causal uncertainty, it is conceivable that with better scientific evidence, causation could be clarified. Scientific uncertainty was referred to in Resurfice in the course of explaining the difficulties that have arisen in the cases. However, this should not be read as ousting the “but for” test for causation in negligence actions. The law of negligence has never required scientific proof of causation; to repeat yet again, common sense inferences from the facts may suffice. If scientific evidence of causation is not required, as Snell makes plain, it is difficult to see how its absence can be raised as a basis for ousting the usual “but for” test.
In para. 52, used the word “ordinary” but only in quoting from the trial judge’s reasons:
 Having rejected the defendant’s expert evidence that the accident would have happened regardless of the excess speed and excess weight, the judge was left with the fact that while there was no scientific proof one way or the other, “[o]rdinary common sense” supported the causal relationship between the injury and the excessive speed and weight (paras. 63-64). He noted, at para. 64, that the motorcycle’s manual itself stated that “[h]igh speed increases the influence of any other condition affecting stability and possibility of loss of control”, and that the defendant agreed the speed at which he was travelling and the load he was carrying were factors that contributed to the accident (para. 33). Finally, the trial judge used language tantamount to finding actual “but for” causation, stating (at para. 67): …
What the trial judge might have meant by that passage is about as clear as what the trial judge meant by the other problematic parts of the reasons. In any event, the “ordinary common sense” phrase was something the SCC used to explain anything.
In para. 56, used merely “common sense”:
 The key finding of fact made by the trial judge was that the plaintiff had not proven causation on the basis of the “but for” test. The trial judge specifically stated, at para. 66, that the plaintiff had been “unable to prove that ‘but for’ the defendant’s breaches, she would not have been injured” (2009 BCSC 112 (CanLII)). Given this finding, it would be exceedingly difficult to draw a common sense inference that those breaches caused the accident. Such inferences cannot be pulled out of thin air at the whim of the trier of fact. They must have a reliable factual foundation.
And, in para. 58, which is the last use of the phrase “common sense”, stated:
 In this case, a factual foundation that would support an inference that the overloading of the motorcycle and excessive speed caused the accident is quite simply lacking. The only evidence directly related to the issue came from the respondent’s expert, Mr. MacInnis. According to his evidence, the accident would have happened even if the motorcycle had been travelling at a lower, legal speed and without a pound of excess baggage. The trial judge evidently rejected this opinion. The fact remains, however, that no evidence was adduced regarding the exact (or even approximate) speed and weight at which the respondent would have been able to regain control of his motorcycle. The state of the evidence therefore leaves precious little room for speculating about robust common sense inferences as to the cause of the accident.
Then, oddly (or chose another adjective: how about “ironically”?): when the Court summarized the “state”of Canadian law on the meaning of but-for, it didn’t use any version of the phrase “common sense” or anything that might mean that phrase. Go figure.
 The foregoing discussion leads me to the following conclusions as to the present state of the law in Canada:
(1) As a general rule, a plaintiff cannot succeed unless she shows as a matter of fact that she would not have suffered the loss “but for” the negligent act or acts of the defendant. A trial judge is to take a robust and pragmatic approach to determining if a plaintiff has established that the defendant’s negligence caused her loss. Scientific proof of causation is not required.
What conclusion do you draw from that absence?
Since, of course, we all know that judges aren’t ordinary, doesn’t that mean that judge’s common sense isn’t ordinary?
In any any event, readers (even judges) would do well to read what Lord Hoffman (once of the now-defunct UKHL and of the Privy Council) had to say about the meaning of claims of resort to “common sense”. For those of you who are litigators and don’t, regularly, check to see what’s in the The Advocates’ Quarterly (Canada Law Book, etc), here’s something from an article that I’m reasonably familiar with, quoting what Lord Hoffman had to say.
“But there is sometimes a tendency to appeal to common sense in order to avoid having to explain one’s reasons. It suggests that causal requirements are a matter of incommunicable judicial instinct. I do not think that this is right. It should be possible to give reasons why one form of causal relationship will do in one situation but not in another.”
Lord Hoffman wrote this in a House of Lords decision, not extra judicially. You can look it up: it’s Fairchild v Glenhaven, easily found on BAILII. He wrote more, extra-judicially: “judges should be encouraged to give the real reasons for their decisions. References to common sense often mean that they have not really thought them through”: Lord Hoffmann, “Common Sense and Causing Loss”, Lecture to the Chancery Bar Association, 15 June 1999, at 12 (unpublished; once available at URL: http://www.chba.org.uk/library/?a=49940; now apparently behind a membership wall; on file with the writer).
Now consider this reminder from a recent (in the legal sense) Ontario Court of Appeal decision: Fisher v. Victoria Hospital, 2008 ONCA 759 at paras 58-59:
 Finally, just as the robust and pragmatic approach cannot be used as a substitute for evidence, it cannot be used as a substitute for reviewing and making findings about relevant evidence.
 Put another way, the robust and pragmatic approach does not permit drawing inferences concerning either the ultimate issue of causation or links in the chain of causation without reviewing the relevant evidence and without making findings about the range of available inferences. … [C]ommon sense cannot become a substitute for resort to evidence: … The mere application of ‘common sense’ cannot conjure up a proper basis for inferring that an injury must have been caused in one way rather than another.
[Most internal quotation marks omitted].
So, if “common sense” without the adjective “ordinary” can’t be used to conjure, what can mere “ordinary” common sense validly be used for? (Probably not much, if we’re intellectually honest. See my article, “Factual Causation in Negligence After Clements” (2013) 41 Advocates’ Quarterly 179, c. 9(1), starting a p. 308. If you don’t have access to the AQ, you’ll find a link to a draft version, here. It’s long, but the relevant section isn’t.)
The late Arthur C. Clarke wrote: ‘”Any sufficiently advanced technology is indistinguishable from magic”. I suspect that one item most of us should be able to agree on is that “common sense”, let alone “ordinary common sense”, whatever else it is, is not advanced technology; nor is it magic. Or, if it is, it’s not effective magic. There are some instances in which the answer to the question in a classic “The Lovin’ Spoonful” song has to be “yes”. This isn’t one of them.
By the way, watch the guitarist’s dance at the beginning of the video. Does it look like some somebody else modified, made better, and made famous in the following decades? If it is, that’s something else to blame Canada for. Truth is the guitarist probably lifted the move from the same sources as the later artist. The guitarist (now dead) is Toronto’s and later Kingston’s own Zal Yanovsky.