Due to his formulation of a modern quantitative and empirical approach, Ibn al-Haytham is considered by some authors to have pioneered the modern scientific method, as well as psychophysics and experimental psychology. In 1802, French physiologist Pierre Cabanis sketched out the beginnings of physiological psychology with his essay, Rapports du physique et du moral de l'homme (On the relations between the physical and moral aspects of man). Cabanis interpreted the mind in light of his previous studies of biology, arguing that sensibility and soul are properties of the nervous system.
Auguste Rodin's The Thinker
German physician Wilhelm Wundt founded the first laboratory dedicated exclusively to psychological research, for which Wundt is often known as the "father of psychology", at Leipzig University in 1879. The American philosopher and psychologist, William James, published his seminal book, Principles of Psychology, in 1890, laying the foundations for many of the questions that psychologists would explore for years to come. Other 19th-century contributors to the field include the German psychologist Hermann Ebbinghaus, a pioneer in the experimental study of memory at the University of Berlin; and the Russian-Soviet physiologist Ivan Pavlov, who investigated the learning process now referred to as classical conditioning.
Starting in the 1950s, the experimental techniques set forth by Wundt, James, Ebbinghaus, and others would be reiterated when experimental psychology became increasingly cognitive—concerned with information and its processing—and, eventually, constituted a part of the wider cognitive science. In its early years, this development had been seen as a "revolution", as it both responded to and reacted against strains of thought—including psychodynamics and behaviorism—that had developed in the meantime.