Do we say actualise or actualize

actualise 1 occurrences

It was this which made him seek to idealise the actual, and to actualise the Ideal.

actualize 2 occurrences

We think that nature has typical forms hovering before it, which it is seeking to actualize in things; when this intention is apparently fulfilled we speak of things as perfect and beautiful; when it fails, of imperfect and ugly things.

For Rodomant had the mathematical gift of all the highest harmonists, and his brain could magnify and actualize the elfin-sized images under his eye to their just and proper proportion in the real."

Do we say   actualise   or  actualize