VII. The main theme

What’s the main Theme of Dead Poets Society?

I think there is more than just one main themes in Dead Poets Society but I have chosen self-determination.

Because already at the beginning,
at the soccer training Mr keating lets everyone decide for themselves whether they want to participate or not.
And the boys in many situations don't let anybody tell them what to do, instead they decide for themselves, for example when Neil wants to act in the theater, he doesn't let his father forbid him to do that and also as Mr.Perry decides to switch him to another school so it doesn’t happen cause Neil decides to kill himself.