Before psychology there was philosophy. Descartes was around during the end of the Renaissance and in the era of revolutionary developments in science. Born in 1596 to a French lawyer, Descartes could understand more than most. When he was in his late 20’s, he resembled more of a scientist than a philosopher since he had studied physics, optics, geometry as well as physiology.
The first to discover that lenses in one’s eyes are inverted by removing an ox’s eye, Descartes also believed in truth and was an active rationalist, meaning he believed the truth would emerge by careful use of reason and it became his modus operandi.
This way to truth was also through the human capacity to reason. He created four rules he used to arrive at truth. He also was the best-known example of a dualist, giving way to accepting a clear partition between mind or soul and body. He believed that the body was like a well-oiled machine and the mind could have a direct influence on it. John Locke followed Descartes in 1632. He wanted to take epistemology, the study of human knowledge and obtaining it, to a more experimental based group of discipline. Locke spurned the idea of innate ideas, only “faculties”.
Some ideas appeared so early in life that they used to believe they were innate but Locke declared that all of our knowledge was derived from experiences. Locke stated that the mind was like a white sheet of paper, blank but able to become something great.
Experiences add to the paper by sensations and reflections. George Berkeley was another philosopher born in 1685. His work on vision was the first example of how empiricist thinking could be applied to the study of perception. Lastly there is David Hume. He built his knowledge around the base premise that all of our understanding is rooted in experience, or impressions vs.ideas.
Impressions are basic sensations experienced daily such as feeling pain, seeing yellow or tasting saltiness. Ideas are faint copies of impressions but are not as vivid. Hume also offered three laws of association: resemblance, contiguity, and cause/effect. Resemblance meaning the look of one object can bring back memories or ideas of another item. Contiguity means intertwining two things together such as the smell of oranges and the west coast. The greatest of the laws is the law of cause/effect.
If one idea causes another idea or memory, the cause reminds you of the effect i.e. burning your hand on the stove while making muffins. When seeing the scar, the memory of muffins will reappear. Hume also suggested that to conclude that A causes B, one must know 1. When A occurs, B must occur regularly, 2. A occurs before B, and 3. B doesn’t occur without being preceded by A. In the 19th century, psychology shifted from being philosophically based to being more scientific. Scientists and physiologists tried to show the world the reasons behind psychology were in fact based on the senses and the nervous system. One example is the Bell-Magendie law.
Both Sir Charles Bell and Francois Magendie both were studying the roots of the postierior and anterior roots of the spinal cord and their functions. Bell was credited with the law because his research was published earlier, though limited, and Bell did not conduct an experiment like Magendie did on puppies. They discovered that the posterior roots control sensation where there is movement still but no sensation. Magendie then severed the anterior root in another animal and the limb was flaccid and unable to move though it still had sensation.
To conclude, the science of psychology has always been a changing domain from philosophy to the sciences. It will continue to grow and develop as the world changes and shifts. Descartes started the ball rolling by studying optics and how to arrive at the truth with his four laws. Locke showed the world that it is nurture vs. nature that shapes a person. Hume gave us the three laws of association. In the 19th century psychology developed to include sciences. All of these philosophers and scientists shaped the psychology field to what it is today.