Read this and answer the question. If the question is unanswerable, say "unanswerable".

A. A. Luce and John Foster are other subjectivists. Luce, in Sense without Matter (1954), attempts to bring Berkeley up to date by modernizing his vocabulary and putting the issues he faced in modern terms, and treats the Biblical account of matter and the psychology of perception and nature. Foster's The Case for Idealism argues that the physical world is the logical creation of natural, non-logical constraints on human sense-experience. Foster's latest defense of his views is in his book A World for Us: The Case for Phenomenalistic Idealism.

What aspect of Berkeley's writing did Foster modernize?
unanswerable