Samuel von Pufendorf's De jure naturae et gentium libri octo appears in 1672, followed in 1673 by a résumé of it under the title De officio hominis et civis ("On the Duty of Man and Citizen"), which, among other topics, gives his analysis of just war theory.

In De jure naturae et gentium, Pufendorf had taken up in great measure the theories of Hugo Grotius and sought to complete them by means of the doctrines of Thomas Hobbes and of his own ideas on jus gentium.

His first important point is that natural law does not extend beyond the limits of this life and that it confines itself to regulating external acts.

He disputes Hobbes's conception of the state of nature and concludes that the state of nature is not one of war but of peace.

But this peace is feeble and insecure, and if something else does not come to its aid it can do very little for the preservation of mankind.

As regards public law, Pufendorf, while recognizing in the state (civitas) a moral person (persona moralis), teaches that the will of the state is but the sum of the individual wills that constitute it, and that this association explains the state.

In this a priori conception, in which he scarcely gives proof of historical insight, he shows himself as one of the precursors of Jean-jacques Rousseau and of the Contrat social.

Pufendorf powerfully defends the idea that international law is not restricted to Christendom, but constitutes a common bond between all nations because all nations form part of humanity.