More than a century ago, an early torts scholar (Pollock) wrote that, when it came to causation, lawyers and judges shouldn't go adventuring with philosophers. Many modern Canadian lawyers and judges are likely more familiar with Sopinka J.'s admonition in Snell v. Farrell against "abstract metaphysical theory" – the claim that causation is "essentially a practical question of fact which can best be answered by ordinary common sense rather than abstract metaphysical theory."
On the other hand, fewer modern Canadian lawyers or judges probably know that a recent article written jointly by a law professor and philosophy professor – an article which certainly has some discussion that some might label "metaphysical theory" – contains a passage that Pollock and Sopinka might have wholeheartedly approved:
An increasing number of philosophers seem to be willing to take the concept of causal connection as a primitive (unanalyzable) concept – one of the conceptual atoms out of which we build more complex concepts or ideas. But one does not need to be overly cynical to wonder whether this embrace is not born out of sheer frustration with the inability to say something interesting yet true about what constitutes the essence of causation. In any event, if the law is waiting for philosophers to offer something better than a prephilosophical grasp of what is involved in one thing causing another, the law had better be very patient indeed.
See R. Fumerton and K. Kress, “Causation And The Law: Preemption, Lawful Sufficiency And Causal Sufficiency” (2001), 64 Law and Contemporary Problems 83 at 105.
And, more than a half-century ago, a famous philosopher, Bertrand Russell, had this to say about the John Locke and Locke' philosophy.
He is always sensible, and always willing to sacrifice logic rather than become paradoxical. He enunciates general principles which, as the reader can hardly fail to perceive, are capable of leading to strange consequences; but whenever the strange consequences seem about to appear, Locke blandly refrains from drawing them. To a logician this is irritating; to a practical man, it is proof of sound judgement. Since the world is what it is, it is clear that valid reasoning from sound principles cannot lead to error; but a principle may be so nearly true as to deserve theoretical respect, and yet may lead to practical consequences which we feel to be absurd. There is therefore a justification for common sense in philosophy, but only as showing that our theoretical principles cannot be quite correct so long as their consequences are condemned by an appeal to common sense which we feel to be irresistible. The theorist may retort that common sense is no more infallible than logic. But this retort, though made by Berkeley and Hume, would have been wholly foreign to Locke's intellectual temper.
[Emphasis added]. See Bertrand Russell, A History of Western Philosophy (New York: Simon & Schuster, Inc., 1967) at 606 (paperback) (at 630 in the 1946 George Allen & Unwin edition).
So perhaps Canadian judges and lawyers can afford to go adventuring with philosophers now and again, albeit properly chaperoned and warded, if only to find ammunition for their petards.
After all, isn't it said that one should keep one's friends close and one's enemies closer?