Originally published in 1968. This book presents the synthesis of a coherent view of the Lockeian argument from his various works. This tests the inner consistency of Locke's political theory against his own examples from history. The layers of Locke's argumentation are analysed on metaphysics in the first part, his attitude towards historical precedents in the second, and in the third with the nature of the regime which he was ready to endorse. This provides the guidelines for a comprehensive reassessment of the liberal tradition, as well as an evaluation of what is still vital to it.