Why did Franz Boas emphasize firsthand fieldwork and observation?

Franz Boas emphasized firsthand fieldwork and observation because he rejected the speculative, ethnocentric theories of 19th-century cultural evolutionism, which attempted to rank societies on a hierarchical ladder of achievement.123

Boas argued that general laws of cultural development could not be assumed; instead, they had to be discovered through the exhaustive, empirical study of individual societies. His commitment to fieldwork was driven by several key principles:41

• Historical Particularism: He believed the anthropologist’s primary task was to describe the unique characteristics of a culture and reconstruct the specific historical events that shaped its current structure.1
• Rejection of Speculation: He scorned the tendency of earlier scholars to select facts that merely supported abstract, preconceived theories.2
• Holistic Understanding: By venturing into the field to gather facts, artifacts, and life histories, researchers could observe how various cultural elements—such as social customs, environment, and language—intermesh to form a functioning whole.2
• Cultural Relativism: Fieldwork demonstrated that cultures are not biologically determined but are shaped by unique historical and environmental circumstances, leading Boas to conclude that all human groups are equally capable of cultural development.43