Hume, however, was compelled to recognize the limits of "the speculative ambition of pure Reason." From speculation he turned to practice. At this time he found both inspiration and warning in the writings of Rousseau. As Kant's antagonism to Hume was only partial, so his attitude to Rousseau was only in part that of an opponent. From Rousseau, Kant learned to "honor men." But Kant "overcame the historical pessimism of Rousseau and his hatred of civilization by a profounder apprehension of the purpose and method of the social struggle." In the interesting discussion of the relations between the three practical moral sciences, — Jurisprudence, Ethics, and Politics, — Politics is found to "crown and complete the system of morals by objective realization of right through a system of universal legislation."
The latter part of the introduction is taken up with an estimate of the importance of Kant's thinking in the science of Politics. The utility of a study of the Kantian writings on Politics is self-evident, when it is remembered that "England has acted out the principles which Kant has thought out and held up for universal imitation and embodiment; and that this holds even more literally of the New England of America."
For an account of the essays themselves, I cannot do better than give extracts from the translator's summary:
"The first essay, entitled 'Idea for a Universal History, from a Cosmopolitical Point of View,' contains Kant's exposition of what may be called the Natural Principle of Politics.
"The second essay discusses the 'Principles of Political Right in Connection with the Relation of Theory to Practice in Politics.' The exposition here given of the theoretical principles of right should be compared with the American Declaration of Independence and the French Declaration of the Rights of Man, as their philosophical counterpart and ultimate expression.
"The third essay contains a short discussion of the 'Principles of Progress,' in opposition to the view of Moses Mendelssohn, who thought it a mere illusion to hold that the whole of mankind here below shall always move forwards in the course of time, and thus perfect itself.
"The essay on 'Perpetual Peace' is a practical exhibition of Kant's principles of politics in the sphere of International Right. It is, in fact, a formal, if somewhat artificial, exposition of Kant's political ideal."
