This chapter discusses the experiment to familiarize the reader with its basic features. It summarizes one set of critical arguments levelled against the experiment. The chapter analyzes the sense in which the mock prison study can be considered to be unethical and presents a body of information relevant to passing judgment on its ethicality from a legal, pragmatic, utilitarian or relativistic model of ethics. The need for an aware, enlightened consciousness among psychologists about the ethics of intervention is more critical than ever remedial practices, selection procedures and cures for a host of social and personal problems. On the basis of such an absolute ethic, the Stanford prison experiment must certainly be a judged unethical because human beings did suffer considerable anguish, yet it was possible to terminate the experiment once that was apparent. The legal counsel of Stanford University was consulted, fire, safety and insurance requirements people had to satisfy.