Ironic - modern art has such a lack of this same openness, that the classic techniques it despises were nearly lost. It was not enough for modern art to be accepted - classical art had to be driven out from contemporary galleries:
The Slade school in London used to be world-famous for turning out fine British draftsmen. A distinguished British painter who taught at the Slade asked me, 'How did you learn how to do animation?' I answered that I was lucky enough to have done a lot of life drawing at art school, so without realizing it I got the feeling for weight which is so vital to animation.
Then I said, 'What am I telling you for? You're teaching at the Slade and it's famous for its life drawing and excellent draftsmen.'
'If the students want to do that,' he said, 'then they've got to club together and hire themselves a model and do it in their own home.' At first I thought he was joking - but no! Life drawing as a subject went out years ago. It wasn't even on the curriculum!
-- Animator's Survival Kit, page 32. https://docs.google.com/file/d/0B-OTUJDZcAzLcDhFbVN3TjdwUnc/...