During the period of the 18th-19th centuries, many new philosophical theories and ideas emerged. John Locke (1632-1704) was the most influential empiricist to many subsequent British empiricists who followed Locke in accepting a mind-body dualism (Hergenhahn, 2009). Locke “distinguished two sources of experience, sensation and reflection: sensation reveals the outside world, whereas reflection reveals the operations of our minds” (Leahey, 2000, p. 389). According to Locke, sensation includes perception, thinking, reasoning, and willing. When the mind perceives in itself or objects in the surrounding environment, the thinking process generates a mental image which Locke called idea (Hergenhahn, 2009).
French sensationalism had much in common with British empiricism. Julien de La Mettrie (1709 -1751), a French sensationalist, believed that “the mind is much more intimately related to the body than Descartes had assumed” (Hergenhahn, 2009, p. 163). La Mettrie claimed that the universe was filled with nothing but matter and motion. In La Mettrie’s theory, thoughts and sensations are also nothing but movements of particles in the brain (Hergenhahn, 2009).
The idea of positivism became widely accepted among intellectuals because of rapid scientific development during that time. The concept and work of positivism were mainly built by French philosopher Auguste Comte (1798–1857). Although Comte endorsed dogmatic empiricism, his positivist system differed from British empiricism. Comte treated the publicly observable properties of physical objects as the subject matter of scientific knowledge rather than the privately introspectable sensations. Comte was contemptuous of introspection as a scientific method and denied the possibility of a psychology based upon it (Greenwood, p. 722). According to Comte, the individual mind is only an illustration because it is neither observable nor physical (Hergenhahn, 2009).
Immanuel Kant (1724–1804) as a rationalist believed that it was an innate category of thought rather than the sensation that provided the experience of time and space. He claimed that “we do not simply experience sensations as they exist on the retina or in the brain” (Hergenhahn, 2009, p. 194). To address the mind-body issue, Kant emphasized that the mind of innate idea was the dominant force which could create a whole experience in the process of perception. But he also argued that it was necessary to link the mind to the sensory elements of the body in order to actively organize the perceived elements to form the mental states of a coherent experience (Schultz & Schultz, 2011).
Hergenhahn, B. R. (2009). An introduction to the history of psychology (6th ed.). Mason, OH: Cengage Learning.
Leahey, T. H. (2000). Psychology: Renaissance through the Enlightenment. In A. E. Kazdin (Ed.), Encyclopedia of psychology, Vol. 6 (pp. 386-394). Washington, DC: American Psychological Association.
Schultz, D. P. & Schultz, S. E. (2011). A History of Modern Psychology (10th ed.). Belmont, CA: Wadsworth.