Gustav Fechner
Fechner, along with Wilhelm Wundt and Hermann von Helmholtz, is recognized as one of the founders of modern experimental psychology. His clearest contribution was the demonstration that because the mind was susceptible to measurement and mathematical treatment, psychology had the potential to become a quantified science. Theorists such as Immanuel Kant had long stated that this was impossible, and that therefore, a science of psychology was also impossible.
Harvey A. Carr
Harvey A. Carr (April 30, 1873 – June 21, 1954), a founding father of functionalist psychology, was renowned for a methodical and thorough approach to his science. His work was largely devoted to studies of animal cognition and perception. Carr collaborated with John B. Watson on his most well-known project: the famous Kerplunk experiment. Carr held his post as chairman of the Psychology department at the University of Chicago from 1926-1938. He also served as the president of the American Psychological Association in 1926.