The mind is the most obvious thing which sets apart human beings from animals. Mind is not synonymous with 'brain', but it is sometimes used to refer to the activities of such.
Voluntarism is the theory of the mind formulated by Willhelm Wundt, and focuses on the aspect of the mind as elements. He believed that the elements were assembled through the power of the will. Chemistry played a significant role in Wundt's theory, as he attempted to use the concept of "the small makes the ultimate result". Wundt worked with Dimitri Mendeleev (The man who wrote the Periodic table of the elements).
Rather than focusing on how the mind works, Structuralism attempts to focus on what the mind is, although it shares a number of ideas with voluntarism, prohibiting it from doing so. This branch, formed by American psychologist Edward Bradfort Titchner focused on stimulus error, and contests that only well-trained observers are capable of introspecting concepts. Titchner offered no means by which a "well trained" observer could be recognised.
Like his predecessor, Wundt, Titchner listed the elements he believed made the mind function, a total of 44,000 sensational elements. He further broke these elements into four categories
- Quality - What separates one sensation from another
- Intensity - How strong the sensation is
- Duration - How long a sensation lasts for
- Clearness - How detailed the sensation is
Unlike Structuralism, Functionalism focused more heavily on what the mind does, and became the dominant model of its time. Functionalism focused on how and what caused the mind to function, and this movement is most closely attributed to John Dewey and James Rowland Angell. It was William James, however, who served as the person who began the functionalist movement. His writings and works, for the most part, stated that an individual created the notion of elements by attempting to stop the mind's ongoing activity. He stated, furthermore, that it was possible for two people to experience the same event in a different way, owing to the different functions of different minds.
The Gestalt Movement
"The whole is greater than the sum of its parts" best summarises the Gestalt movement. This branch referred to Structuralism and Functionalism as "brick and mortar psychology", and saw the "whole" experience of the mind as a Gestalt. The primary characteristic of the Gestalt is the importancs of the consciousness, and the belief that wholes cannot be reduced to a listing with a description of the parts. The Gestalt movement proposed Principles of Perception, which focus on how we tend to group objects.
- Proximity - Similar objects group
- Similarity - Similar looking objects group, even despite proximity
- Pragnanz - The idea that we naturally attempt to make a "perfect shape"
- Closure - Our tendency to complete incomplete shapes.
Perhaps the most well known branch, Psychoanalysis was founded by Sigmund Freud and focuses on the three divisions of the mind, the Ego, the Superego, and the Id. Freud proposed that the Id, being completely unconscious, was in control of our wants and desires, and demanded immediate satisfaction of its wants. The Superego was responsible for our ethical sense, seeking to suppress the Id, and the Ego balanced the needs of the Id and Superego. The Ego operates on what Freud termed the "reality principle", operating in a rational and pragmatic fashion.
The weaknesses in Freud's theory were the strengths that made up Behaviorism. Instead of attempting to describe the complexity of the mind, the Behaviorist branch focused on behavior. In the view of Behaviorists, the internal workings of the ind are too complex to be measured in an objective and scientific fashion, and that behaviors, being observable, are the best way to describe the mind. Humans, for the sake of study, were de facto lumped into the same category as animals, making behaviorism a more general science.
Rev. Sun Myung Moon said,
- We should live based on the mind. However, this world has become a totally materialistic world in which many people do not even think about whether they have a mind or not. We can understand this fact by looking at the current education system, which puts so much emphasis on materialistic civilization and values. Modern people have such little regard for the valuable mind inside each person. Rather, their focus is fixed on the money before their eyes. They drift towards denying the mind and God. 
Mind in Buddhism