In conclusion, ‘Two Concepts’ uses the appropriate methods to successfully distinguish between negative and positive liberty and then to show that humans ought to value negative liberty. However Berlin uses an unequal and confusing blend of historical political theory and conceptual analysis to try and highlight the dangers of pursuing positive liberty. His historical analysis is incomplete and wanting of the key concepts in the theory. It would be improved by more rigorous use of techniques in historical analysis and by an accompanying analysis of negative liberty.