Edwin Nevis described Gestalt therapy as "a conceptual and methodological base from which helping professionals can craft their practice". In the same volume,
Joel Latner stated that Gestalt therapy is built upon two central ideas: that the most helpful focus of psychotherapy is the experiential present moment, and that everyone is caught in webs of relationships; thus, it is only possible to know ourselves against the background of our relationships to others. The historical development of Gestalt therapy (described below) discloses the influences that generated these two ideas. Expanded, they support the four chief theoretical constructs (explained in the theory and practice section) that comprise Gestalt theory, and that guide the practice and application of Gestalt therapy.
Gestalt therapy was forged from various influences upon the lives of its founders during the times in which they lived, including: the new physics, Eastern religion, existential phenomenology, Gestalt psychology, psychoanalysis, experimental theatre, as well as systems theory and field theory. Gestalt therapy rose from its beginnings in the middle of the 20th century to rapid and widespread popularity during the decade of the 1960s and early 1970s. During the '70s and '80s Gestalt therapy training centers spread globally; but they were, for the most part, not aligned with formal academic settings. As the cognitive revolution eclipsed Gestalt theory in psychology, many came to believe Gestalt was an anachronism. Because Gestalt therapists disdained the positivism underlying what they perceived to be the concern of research, they largely ignored the need to use research to further develop Gestalt theory and Gestalt therapy practice (with a few exceptions like Les Greenberg, see the interview: "Validating Gestalt"). However, the new century has seen a sea of change in attitudes toward research and Gestalt practice.
Gestalt therapy is not identical with Gestalt psychology but Gestalt psychology influenced the development of Gestalt therapy to a large extent.
Gestalt therapy focuses on process (what is actually happening) over content (what is being talked about). The emphasis is on what is being done, thought, and felt at the present moment (the phenomenality of both client and therapist), rather than on what was, might be, could be, or should have been. Gestalt therapy is a method of awareness practice (also called "mindfulness" in other clinical domains), by which perceiving, feeling, and acting are understood to be conducive to interpreting, explaining, and conceptualizing (the hermeneutics of experience). This distinction between direct experience versus indirect or secondary interpretation is developed in the process of therapy. The client learns to become aware of what he or she is doing and that triggers the ability to risk a shift or change.
The objective of Gestalt therapy is to enable the client to become more fully and creatively alive and to become free from the blocks and unfinished business that may diminish satisfaction, fulfillment, and growth, and to experiment with new ways of being. For this reason Gestalt therapy falls within the category of humanistic psychotherapies. As Gestalt therapy includes perception and the meaning-making processes by which experience forms, it can also be considered a cognitive approach. Also, because Gestalt therapy relies on the contact between therapist and client, and because a relationship can be considered to be contact over time, Gestalt therapy can be considered a relational or interpersonal approach. As it appreciates the larger picture which is the complex situation involving multiple influences in a complex situation, it can also be considered a multi-systemic approach. In addition, the processes of Gestalt therapy are experimental, involving action, Gestalt therapy can be considered both a paradoxical and an experiential/experimental approach.
When Gestalt therapy is compared to other clinical domains, a person can find many matches, or points of similarity. "Probably the clearest case of consilience is between gestalt therapy's field perspective and the various organismic and field theories that proliferated in neuroscience, medicine, and physics in the early and mid-20th century. Within social science there is a consilience between gestalt field theory and systems or ecological psychotherapy; between the concept of dialogical relationship and object relations, attachment theory, client-centered therapy and the transference-oriented approaches; between the existential, phenomenological, and hermeneutical aspects of gestalt therapy and the constructivist aspects of cognitive therapy; and between gestalt therapy's commitment to awareness and the natural processes of healing and mindfulness, acceptance and Buddhist techniques adopted by cognitive behavioral therapy."