One of the best things about the English language, and indeed one of the main reasons for its global dominance, is its enthusiastic ability to welcome words from foreign languages as its own. There is hardly any language in the world from which English has not purloined a word or two, from obvious French words such as café and entrepreneur to aboriginal Australian terms like kangaroo and boomerang. Even the common word “launch” (used as a noun) is borrowed from Malay. And of course a huge portion of the English vocabulary is taken from Latin.
It is this use of Latin that I want to address, given the historically prevalent role of Latin in legal English. This is the consequence of the heavy and continuing influence of Roman law on both continental and English law, the latter of which is the basis of Singapore’s legal system.
Yet I think that Latin obscures too much of legal writing, rendering it incomprehensible and incoherent to lawyers and non-lawyers alike. Plain English movements and campaigns have targeted legal writing since the 1970s and the reduction of unnecessary Latin is one of the measures. Here I propose when Latin is acceptable in legal writing, along with a couple of my pet peeves.
1) When describing a specific legal concept. This is probably the most common use of Latin. Concepts like audi alteram partem and restitutio in integrum are known mainly or solely by their Latin names.
2) Concepts that have no easy or neat equivalent in English. This is similar to the first category. The statutory canons such as ejusdem generis and expressio unius exclusio alterius are some examples.
3) Latin terms that are used in general non-legal English. A fortiori, mutatis mutandis, per se and caveat emptor fall into this category.
Some terms, of course, come under more than one category. Others barely qualify. An example is “bona fide”. It is entirely replaceable with “in good faith”. Personally, I always use “in good faith”. To some people, however, the Latin term may carry a slightly stronger legal gloss that the English term does not have or they have in mind a distinction between legal good faith and general good faith.
Another example is “in pari materia”. One can correctly and easily say “section X is exactly the same as section Y of the English statute” and mean the same thing as “section X is in pari materia with section Y of the English statute”. Again, I imagine some people consider the Latin phrase to imply a certain legal comparison beyond mere exact similarity. I do not know of any such implication.
But those are not the pet peeves I was referring to. The two Latin phrases that make me want to cringe and cry are inter alia and arguendo. They literally, directly and completely translate into “among other things” and “for the sake of argument” respectively, with no meaningful layer, nuance or gloss, legal or otherwise. They are almost never used in non-legal contexts and yet are found far too often in Singaporean judgments and academic articles. A Lawnet search for “arguendo” reveals 60 Singapore cases that used the word. The count for “inter alia” runs into the thousands (I gave up). Some of the champions in this regard are Wing Joo Loong Ginseng Hong v Qinghai Xinyuan Foreign Trade  2 SLR(R) 814, a trade mark case with 41 instances of “inter alia”, Mercurine v Canberra Development 4 SLR(R) 907 with 24 “inter alia“s and Review Publishing v Lee Hsien Loong 1 SLR 52 with 23. Is “among other things” too vulgar and crude for the courts?