This is a complex and theoretical study on the roles of language and art in Navajo culture, resulting from nearly a decade of research on the Navajo reservation. The structures of Navajo thought, language, speech, and knowledge are used to frame discussions on a number of topics. Primary among these from a cosmological perspective are the concepts of inner and outer forms in the duality on nature coupled with static and dynamic concepts of motion. Also explored is the importance of language in ritual control and perceptions of action, causality, and plurality. Two terms essential to the Navajo ethos are semantically explored as organizing principles. The first is the concept of k'T which finds its primary expression in the patterning of kin relationships and solidarity. The second is h=zh=, which is most easily glossed as representing Navajo ideals of harmony and order. Art examples, represented by music, sand painting, and weaving, are used to demonstrate how these complex semantic and cosmological considerations find their way into Navajo daily ritual life. Information is also included on color classification, numerology, mythology, ethnophysocology, and taxonomies. The conclusions expand the data into summary statements of Navajo ethos.