Navajo philosophy, documented in careful detail by James Kale McNeley based on fieldwork and interviews conducted in the Navajo Nation, describes Nilch'i, Holy Wind, as a single entity existing everywhere at once and present within every living thing, rather than a bounded personal soul of the kind assumed in much Western religious thought; the Wind does not belong to the individual so much as the individual participates in the Wind. According to Navajo tradition, after the Emergence onto the earth's surface, winds and their inner forms were placed within all living beings, humans, animals, plants, and even features such as mountains and celestial bodies, as the shared source of their life, movement, speech and characteristic behavior.
A child receives Wind at conception, when the winds carried respectively by the father and the mother unite into the vital breath given to the child-to-be, and further winds are said to endow the maturing person with awareness, judgment and the capacity to control their own conduct as they grow. Nilch'i is bound up specifically with breath, speech and thought: it is described as entering and leaving the body with breathing, and as the very means by which a person is able to think and to speak, so that Navajo accounts of right conduct are framed substantially in terms of the Wind functioning as it should rather than as separate ethical rules imposed from outside.