This unique text provides a framework for evaluating various theories and a context for addressing social work practice with varying levels of social systems.This revision places current theories of human behavior in a systems context. It is based upon a generalist practice foundation and includes practice examples that help students understand the underlying theory. The text examines the basic concepts in each of the various system sizes: the individual, the social group, the family, the organization, and the community. It includes expanded coverage of spirituality, diversity, values and ethics; social and economic justice/oppression; populations-at-risk; and other areas.The Fifth Edition presents new theoretical models in the areas of spirituality and individual development, discussion of spirituality is integrated throughout. Provides Expanded and integrated information on diversity is also included through out the text. And finally, this edition uses the concept of holon as a unifying construct at all systems levels.