This Fourth Edition explains and puts into practical perspective the format, choice of wording, aspirational principles, and enforceability of the Ethical Principles of Psychologists and Code of Conduct. Providing in-depth discussions of the foundation and application of each ethical standard to the broad spectrum of scientific, teaching, and professional roles of psychologists, this unique guide helps practitioners effectively use ethical principles and standards to morally conduct their work activities, avoid ethical violations, and, most importantly, preserve and protect the fundamental rights and welfare of those whom they serve.