Navi: Slaves to Mother Nature?

Rosseau discusses that the main difference between man and brute is man's quality of free agency. He argues that the brute hears and obeys mother nature's voice, but that the man, although receiving the same impulsion, has the unique ability to choose his course of action. This is an interesting argument when considering the behavior of the Navi in relation to mother nature. Avatar portrays the Navi as highly intelligent in all regards, but still considers them as savages or brutes in the context of the film's diegesis. Most people read the Navi's respect for nature as as choice backed by strong emotion, but what if they were actually slaves to their basic instincts? The Navi could have developed their intelligence while, through spirituality, still retaining their instinctual drive for upholding the balance of nature as was shown in the scene where Neytiri protects Jake by killing a hostile beast. Although, it seems more likely that Rosseau is simply making boundless and blatant assumptions about the lives of early humans, and that the Navi have simply found that respecting the balance of nature is the most beneficial way for them to sustain themselves.