As found in Bruce Lee: Artist of Life, which provides unique insight into the mind of Bruce Lee through his private letters and writing.
1. Aboutism keeps out any emotional responses or other genuine involvement — as though we were things. In therapy, Aboutism is found in rationalization and intellectualization, and in the “interpretation” games where the therapist says “This is what your difficulties are about.” This approach is based on noninvolvement.
2. With Shouldism you grow up completely surrounded by what you should and should not do, and you spend much of your time playing this game with yourself—the game I call the “top dog/underdog game” or the “self improvement game” or the “self-torture game.” Shouldism is based on the phenomenon of dissatisfaction.
3. The Existential (“is-ism”) approach is the external attempt to achieve truth, but what is truth? Truth is one of what I call the “fitting games.”
4. Gestalt attempts to understand the existence of any event through the way it comes about, which tries to understand becoming by the how, not the why, through the all-pervasive gestalt formation; through the unfinished situation, which is a biological factor. In other words, in Gestalt therapy we try to be consistent with every other event, especially with Nature, because we are part of nature.