The absolutist assertion, commonly made by moral relativists, that “there are no absolutes” is self-refuting. That’s not the case for Justice Scalia and Bryan Garner’s third fundamental principle, which reads: “No canon of interpretation is absolute. Each may be overcome by the strength of differing principles that point in other directions.”
For starters, the principle of non-absolutism in the first sentence applies not to itself but rather to the 52 canons that Scalia and Garner elaborate. Further, read in the context of the second sentence, the first sentence would seem to mean only that “No canon of interpretation is always dispositive” (when it comes into play at all, that is), not that “No canon of interpretation is invariably sound.” (I read a later passage, on page 176, as confirming this reading.)
Scalia and Garner take on Karl Llewellyn and “modern critics” like Judge Richard A. Posner who disparage the canons as contradictory and malleable. Scalia and Garner acknowledge that the canons “can be abused, as every useful tool can be abused,” and that, like clues in a good mystery, they “often point in different directions.” But the challenge for a good judge is to sort through how the canons interrelate on a particular question—and that sorting process is aided by the deep and clear understanding of the canons that their treatise aims to supply.
Far better to have judges who regard themselves as detectives solving linguistic mysteries than as super-legislative Mr. Fix-Its or as social engineers.