Eight philosophical schools of criminology are examined: 'classical' realism, the 'classical' philosophical idealism of Beccaria, the utilitarianism of Bentham, the positivism of Lombroso, the naturalism of the psychologists, the pragmatism of the sociologists, the analytic philosophy of the Marxists, and the author's own existential viewpoint. The discussion also focuses on historically related ideas in other disciplines as varied as art and architecture, science, theology, and historiography. The book critically examines criminal justice institutions and the motives of those responsible for existing systems of police and prisons. The book concludes that the history of criminology reflects the philosophy of the times while retaining elements of older schools of thought. Existentialism, a contemporary philosophy, remains to be incorporated in modern criminology. Existentialism is discernible in the roots of crime, particularly if crime is viewed as an example of a 'will to power.' Chapter notes, subject index, and 350-item bibliography.