I've always understood the "rule" to be Greek-origin words take 'ize' and Latin-origin words take 'ise'. Personally I would rather have one or the other consist

I've always understood the "rule" to be Greek-origin words take 'ize' and Latin-origin words take 'ise'. Personally I would rather have one or the other consistently. I use 'ise' in all cases by default, but if I know my audience is American I use 'ize'. I'm not precious about it.