Book excerpt: This concentrated, critical study of Juan Luis Segundo reveals some of the deepest impulses of liberation theology itself. The book proves the implications of Segundo's dialogue with the social sciences and in particular, demonstrates the powerful impact of Karl Marx's social philosophy on Segundo's thought. The book explores the difficult yet fascinating contradictions that arise when theology attempts so thorough an integration of Marxian categories and concepts into its own methodological core. The profound influence of Marx on Segundo indicates the general indebtedness of liberation theology to Marx, with the effect that theology goes beyond itself and into social theory while maintaining its religious dimension. No study by a North American has yet focussed so pointedly on this crucial aspect of Segundo's work which shows the real challenge of liberation theology to all theology.