The schools of thought by a couple of psychologists in the twentieth century, with the study of psychology as a discipline has saw it benefit from several psychologists and other visionaries individuals who have significantly contributed to the subject (Heatherton, 2006).
These great men include Carl Jung, William James, Sigmund Freud, and Alfred Adler. This paper therefore attempts to look at their central ideas as regards to the nature and cause of human psychological functioning.
Sigmund Freud has made a towering contributition to the field of personality. His theories on personality, developmental stages, as well as defense mechanism have attracted many scholars in the field of psychology.
His theory of personality is made up of the levels of consciousness, the development of personality, the structure of personality, the source of motivation, and the nature of human beings. Freud argues that there are three levels of consciousness, the conscious, the pre conscious, and the unconscious. What we are aware of is our councious mind while the preconscious is simply made up of thoughts and feelings. These are not conscious but are able to graduate to the conscious stage. The unconscious is made up of thing we cannot become aware of, may be were forgotten due to some reasons and kept as 'repression'.
Regarding libido, Freud believed that children were born with libido, a certain amount of mental energy, which becomes the driver for adult sexual desire. He holds these two instincts, which drive individuals, sexual drive-by libido and live preserving drives such as pain and hunger (Heatherton, 2006).
Although Freud appears to concentrate much on the libido, his theory of the unconscious mind is termed as his greatest contribution as long as psychology is concerned. Through his theory that splits psychological functioning of human beings into several layers, he postulates that only the obvious and the councious control behavior. He also holds that the suppressed and unsaid is also crucial in shaping actions and behavior. The recognition of the unconscious sets Sigmund apart as a psychologist of then. Freud also studied and tried to explain how the unconscious affects behavior and the way of doing things (Ouma, 2000).
On the other hand, Carl Jung also dealt with the unconscious in his theories. He however advocated for exploration of psychology, religion, and dreams. He also considered mythology and art. Apart from the unconscious, his study also integrated the divine intervention to the unconscious. He argues that both are related and goes together. He did not attach a lot of merit to logic and hard science to explain psychology. He sought for harmony and balance. Just like Freud, he dealt with the unconscious but made some additions through the inclusion of religion.
Alfred Adler also studied the unconscious. His study differs with that of Freud and Jung with the introduction of counseling and psychotherapy. He dealt with the personal level of psychology as well as social equity as one of the factors that can prevent mind illness. Together with his psychological social aspect, he studied relationships in the society that are built on power (Ouma, 2000).
On the other hand, William James explored religion and mysticism. He explored truth and argued that nature cannot be frozen in time and space. He postulates that truth depends on how useful it is to the individual who believes the truth. In describing how one's mind connects to the world, he used the concept of stream of consciousness. This concept is also in line with the Unconscious in explaining human behavior, which eventually unites all the four scholars (Raymond, 2004).