Boas was strongly committed to empiricism, and was skeptical and critical of attempts to formulate "scientific laws" of culture. He was also a strong advocate of ethnographic fieldwork, and argued that specific cultural traits -- behaviors, beliefs, and symbols -- had to be understood in terms of their local context. As such, he was a major contributor to the anthropological concept of cultural relativism.
Boas also encouraged the "four field" concept of anthropology, and contributed not only to cultural anthropology but to physical anthropology, linguistics, and archeology as well. In physical anthropology he challenged various uses of the notion of race, and argued that there was no necessary or strong connection between race and culture.
One of his students at Columbia also included, anthropologist, folklorist and novelist Zora Neale Hurston.