Conversation so far:
What did e do with martial arts?
won gold medals.
when did he start learning martial arts?
learned Tai Chi from a young age under his mother's tutelage.
did anyone else teach him?
Beijing Sports Institute, the same facility where champion-turned-actor Jet Li trained.
how long did he train there?
CANNOTANSWER.
What was his style like?
Yen believes that combining many martial arts together will produce the most effective and harmonious style.

Question: what about his philosophy?
Self-contained rewrite: what was Donnie Yen's martial arts philosophy like?