Last Updated September 6, 2023.
In The Principles of Psychology, William James describes psychology from a scientific standpoint. This differs from previous approaches to psychology, which were more dependent on introspection. James takes a more practical approach to psychology, applying his knowledge of physiology.
Psychology is the Science of Mental Life, both of its phenomena and of their conditions. The phenomena are such things as we call feelings, desires, cognitions, reasonings, decisions, and the like; and, superficially considered, their variety and complexity is such as to leave a chaotic impression on the observer.
The Principles of Psychology describes the causes and effects of the human brain. Breaking down human instincts and emotions into dozens of different types, James writes that experience moderates these predispositions into human actions.
The brain forms associations among connected ideas. These associations assist in processing information. More complicated thoughts build on basic psychological components. Abstract thought arises from habit, as more sophisticated brains developed from more straightforward animal brains.
All nervous centres have then in the first instance one essential function, that of "intelligent" action. They feel, prefer one thing to another, and have "ends." Like all other organs, however, they evolve from ancestor to descendant, and their evolution takes two directions: the lower centres passing downwards into more unhesitating automatism, and the higher ones upwards into larger intellectuality.
As the brain builds on its instincts, habits, emotions, and thoughts, combining them through associations, a bigger picture emerges. This changing picture is consciousness, the awareness of the environment—and this complicated yet personal consciousness, in turn, serves to bring order to the messy events that fill the brain, enabling people to survive.
From this series of experiences—that is, consciousness—the brain builds a notion of the self. The self represents the set of properties relating to its own mind. These include the person, as well as the person's belongings, relationships, and so forth. In addition, the self includes its ideals or desires: what it wants. A person's self-esteem depends on how much one's actual self matches one's ideal self.
The Empirical Self of each of us is all that he is tempted to call by the name of me. But it is clear that between what a man calls me and what he simply calls mine the line is difficult to draw.
Some psychological events take place outside of consciousness. These subconscious events include habits. As people become increasingly accustomed to committing basic responses to the environment, these physiological responses stabilize. At a group level, habits enable society to function smoothly, letting people focus conscious thoughts on more important developments.
The brain carefully focuses on certain aspects of the environment. This enables the brain to act appropriately in the large and changing situations in which people find themselves without becoming overwhelmed. By building an awareness of the environment and comparing it with associations from memory and thinking, the brain can process the environment into a sensible view.
In addition to observing and focusing, the brain filters and processes. Some events or ideas are considered realistic, and others unrealistic. The most precise forms of processing—that is, those involving careful consideration—are considered reasoning, which uses intuition and facts to discern difficult truths.