The essay warns that scientific and technological advances, while greatly increasing human control over nature, may strengthen dominant groups and produce harm under current political and economic arrangements. It sorts knowledge into physical, biological, and anthropological sciences, arguing that physical science has already driven industrial change, anthropological studies have so far influenced society mainly through medicine and birth control, and biological developments promise powerful but uncertain future effects such as heredity manipulation and disease control. The author emphasizes that human passions and instincts can become maladapted to new conditions, creating intensified rivalry and conflict unless social restraints are adopted.