Why did William James describe thought as adaptive and purposive?

William James described thought as adaptive and purposive because he viewed the mind through a functional and biological lens, heavily influenced by the work of Charles Darwin.12

In his seminal work, The Principles of Psychology, James argued that thinking and knowledge function as instruments in the struggle to live. He believed the primary purpose of thought is to help individuals establish "satisfactory relations with our surroundings," allowing people to navigate their environment and fulfill their needs and desires.21

James characterized this as a teleological conception of the mind, where the "pursuance of future ends and the choice of means for their attainment" serve as the defining criteria of mentality. By treating ideas as tools for expediting action, James posited that thought is not merely a passive reflection of reality but an active, purposive process that helps individuals mold their environment and create the future.1