Carl Rogers person-centered approach (PCA) is strongly related to systems The core theoretical and explanatory principle—actualizing tendency—was coined by the Gestalt psychologist Kurt Goldstein. Moreover, in some of his late papers, Rogers stressed the relationship of PCA and interdisciplinary systems theory. Starting from this historical perspective, this chapter provides an introduction into some core concepts of systems theory. The actualizing tendency in PCA is connected to the phase transition in systems theory, both representing transformational processes from old, inadequate patterns to new, better adjusted ones. This notion refers to Goethe’s famous slogan of transformation “Die and Become!” where symptoms are an over-stability of patterns inadequate to solve new tasks. Although these patterns are sorrowful, they are familiar to the person, and their “death” is coupled with angst and horror. Therefore, a supporting personal relationship, characterized by the “necessary and sufficient conditions” and giving of trust to that “die and become,” is so important. Furthermore, the booklet gives an outline of the “Person-Centered Systems Theory” which focuses on processes in different levels of human life. While the PCA has very well-developed person-to-person relationships, it has neglected structural influences of culture, meaning, and language as well as their interconnections. An integration of these aspects into the PCA would be of value. Finally, we discuss how meaning is created and how we understand things in psychotherapy and everyday life.