The term, "noble savage" is really an oxymoron as the literal term "savage" seldom has any nobility attached to it. As a philosophical term, however, and according to Encyclopedia Britannica, it is defined to
an idealized concept of uncivilized man, who symbolizes the innate goodness of one not exposed to the corrupting influences of civilization.
With this definition in mind, it's easy to picture the early Indians on this continent as wild, innocent, free, brave, and noble. Their ways may have been repulsive and their lifestyle uncivilized to the English colonists, but within their own societies, they viewed themselves differently.
Chief Joseph of the Nez Perce is an example of a "noble savage." In all his dealings with his own people and with the white man he acted bravely, honorably, and nobly; his whole interest was the preservation of his people, their lands, and their way of life.