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.
Monte B. Shapiro
Monte B. Shapiro (May 31, 1912 – April 29, 2000) was considered to be one of the founding fathers of clinical psychology in the United Kingdom (as noted by the University of Kent as well), along with Hans Eysenck. He is credited by Kings College London as developing the scientist-practitioner model in the UK.