I am a closet pedant. Yes, I admit it.
When I hear people say something like “I’ll try and do it better”, I inwardly wince.
When I hear people use a word like ironical (instead of ironic), I die a little death.
However, in the latter case at least, it turns out that my annoyance could be misplaced, and in fact, the “-ic” versus “-ical” question is a bit of an unresolved mystery. In fact, it seems like it points to some weirdness going on in the English language.
The problem arises because you can turn many nouns into adjectives by adding a various suffixes. Some common ones are the “-ic” suffix (e.g. history becomes historic), the “-ish” suffix (e.g. book becomes bookish), the “-al” suffix (e.g. nation becomes national), and the “-y” suffix (e.g. box becomes boxy). However, suffixes can be added to other suffixes, and you can easily end up with abominations.
Why do we need words like ironical, symmetrical, or problematical, when ironic, symmetric and problematic are already doing a fine job?
I admit that there are a few places where the “-ic” and “-ical” adjectives have different meanings, such as historic(al) or economic(al). However, it seems that solid differences are the exception, rather than the rule.
I recently came across this study by Stefan Th Gries, which takes a deep look into the literature on this matter and also draws new conclusions based on a statistical investigation of a large corpus of English texts. The conclusion that I came to, after reading it, was that differences between the “-ic” and “-ical” adjectives seem to vary between regions and across time. Sometimes the variants of an adjective move further apart and then move closer together again. They are words that are pegged to the meaning of the underlying noun, but by dint of being separate words, have separate lives.
It reminded me of the theory of genetic drift. At least, to the extent that as difference in utility between using the “-ic” or “-ical” variant is so slight, it may be essentially random population effects that could be driving the frequency of using a particular variant for a particular purpose. Some variants happen to become sufficiently popular for a particular use, and that meaning becomes stuck.
I have now realised that here in Melbourne, we have two old gardens that are relevant to this discussion. The Royal Botanic Gardens were founded in 1846, while the Royal Zoological Gardens were opened in 1862. (In fact, animals were kept in the Botanic Gardens until the Zoo opened.) Even though these places were named around the same time, one has an “-ic” style name and the other has an “-ical”. The word “zoologic” seemed to have by then (and still today), for whatever reason, fallen out of fashion, while its companion word, “botanic”, continued to be popular.
I am going to continue to despair for those people that use “ironical” but I think I’ll cut the others a bit of slack.