(..) Such transfer of a common noun to the proper noun category occurs over and over again in English tribal nomenclature for California Indians, through the chance that the commonest initial inquiry of a white traveler made to a strange Indian took the form, "Who are you?", to which the usual Indian answer was, "I am a person." What else was he to answer? It was a rude question, whether rudely meant or not. One did not say one's name, certainly not to a stranger. One belonged to the people. One was a person.
As for saltu, Ishi's name for the white race, it means a being of another order, a non-human, a pre-human, or a spirit. It is often translated as meaning ghost, but this is not, strictly speaking, correct. There are other words for ghost and for soul. All Indians tend to have a word like saltu that has been used, anciently, for a different and special category of being and which fits the need for a word to designate the white race. There attaches to saltu neither the denigration usual to our use of the word "native," or "primitive," nor does it imply a superior being. It is denotative of difference, as of a separate phylum.

(Theodora Kroeber "Ishi in Two Worlds: A Biography of the Last Wild Indian in North America")