Gestalt Therapy was developed from theories of perceptual psychology, in which the concept of "foreground" and "background" are quite important. Human needs are experienced as "gestalten" (German for "whole things") which become stronger in awareness (in the perceptual foreground) until we meet the needs, and then they recede into the background. A well-adjusted person is one in whom there is a constant flow of needs and the satisfaction of needs.
Neurosis or maladjustment, then, is related to something within the person which blocks or interferes with the healthy flow of the awareness of needs and taking action to satisfy them. This philosophy fit in very well with the concepts and philosophies of the 1960's and 1970's in which the freedom to feel, experience and express was paramount. Frederick S. ("Fritz") Perls was the main person teaching and promoting this school of therapy, which eventually became extremely popular.
The uncovering and resolving of interpersonal issues is the main focus of Gestalt Therapy. Unresolved issues are unable to fade into the background of consciousness because the needs they represent are never met. So, in Gestalt Therapy we try to discover with whom we have unresolved issues, and we try to engage those people (or our internal images of those people) in interactions which could lead to a resolution.
One of the things that was attractive about Gestalt Therapy was that the time frame required to resolve problems seemed to be considerably shorter than that of traditional, psychoanalytic therapy. It was also more dramatic, interesting and fun than analysis, and you could share the experience of getting well with other people, in contrast to the isolated and secretive way that psychoanalysis works.
Gestalt Therapy developed into a form of therapy which emphasized medium to large-sized groups, although many of the techniques of Gestalt Therapy are applicable to individual work as well. The "encounter group" and "sensitivity training" movement, and eventually the whole Human Potential Movement of the 1980's and 1990's, had their roots in the techniques and philosophy of Gestalt.
Some of the most powerful techniques involve role-playing, such as talking to an empty chair in which you imagine that a person, with whom you have an unresolved issue, is in the chair responding to your expressed feelings. Although this technique sounds artificial and makes some people feel self-conscious, I have witnessed and experienced the powerful way that this approach brings out buried feelings and can help a person discover where and how they are blocked from being fully alive.
The use of "battacca bats," padded sticks which are used to hit chairs or sofas with, to aid in the experience and safe expression of anger, was also pioneered in the Gestalt Therapy movement. Another innovative approach which was often used was the Gestalt Therapy Marathon, in which the participants and one or more facilitators had group therapy from Friday night straight through Saturday night or Sunday, without stopping. The effect of the heightened emotionality and the lack of sleep serve to eliminate many psychological defenses and allow significant progress to be made in a short time.
Although Gestalt Therapy has perhaps passed its heyday, it is still a viable approach to personal growth and many of the techniques still have value, including the "empty chair" technique and variations of it. These techniques can allow a person to work through unresolved issues with a person who would not participate in therapy, or even with a person who is dead and gone.