Examining American psychology's development from a Jungian perspective, Jennings argues that the discipline is at a point where a deeper and broader exploration of spirituality is essential in order to realize the goal of creating a complete psychology of human beings. Having already developed an understanding of the person that rests upon the tenets of behavioral, cognitive-behavioral, psychoanalytic, humanistic, and existential approaches, many mainstream American psychologists now seem eager to embrace a growing viewpoint of the person grounded in biological psychology, which draws the discipline closer to a materialistic understanding of human beings. This direction in American psychology reinforces a strikingly unbalanced viewpoint of human nature that does little to reveal the fullness and purpose of human spirituality. To address this deficiency, Jennings encourages more American psychologists to integrate spiritual concepts readily explored in transpersonal psychology with respect to our more traditional psychological understanding of what it means to be human.