This introductory chapter discusses basic terms as well as perspectives and paradigm shifts that have contributed to the emergence of environmental psychology. We first define the term environmental psychology, then explain terms such as environment, nature, and civilization, and discuss the “three environments” according to Willy Hellpach. Subsequently, we illuminate the historical backgrounds of environmental psychology. We start with the biological influences, from Darwin’s theory of evolution to Uexküll’s theory of meaning to Haeckel’s ecology. We then address developments within psychology, ranging from American functionalism to Barker’s behavior-setting approach and new evolutionary psychological findings. Finally, we discuss deterministic, possibilistic, and transactionalistic ways of thinking and briefly touch on systems analysis as a possible methodological approach to complex environmental problems.