Wikipedia's article on vespers contains this passage (my emphasis):
The name, however, by which it was most widely known during that period was Lucernalis or Lucernaria hora (l. c., 126). This name is characteristic. It was so called because at this hour a number of candles were lighted, not only to give light, but also for symbolical purposes.
I think I would have said for symbolic purposes. This got me thinking: do 'symbolic' and 'symbolical' mean the same thing? I couldn't tell you any difference between them.
If that's the case, it seems redundant to make use of both. There will be times when one or the other is more appropriate for contextual reasons (eg if you need something to rhyme!), but in general, should we prefer one over the other? I lean towards preferring 'symbolic', because it's shorter and cleaner.
More generally, is 'symbolical' some sort of hypercorrection? Or, if not hypercorrection, is it in the same genus as 'burglarize', where words grow unnecessary decorative plumage at the end which emphasises which part of speech they are?