A little knowledge that acts is worth infinitely more than much knowledge that is idle.
Books are but waste paper unless we spend in action the wisdom we get from thought – asleep. When we are weary of the living, we may repair to the dead, who have nothing of peevishness, pride, or design in their conversation.
If you have a vaccine or an antidote that people can benefit from, you’re not going to want to keep it to yourself. You’re going to want to spread that wisdom or whatever to as many people as you can, so everybody can benefit from it.
Second, this epic tale allows the audience to actually listen to the Native Americans and receive their wisdom. Spielberg conveys the respect for Native Americans that is normally lacking in Western films.