In the seventh chapter it is shewn, that the Eastern sea, or the right of navigation in it, cannot belong to the Portuguese by prescription, since prescription being only by the civil law it cannot operate against the law of nature, by virtue of which, navigation in that sea is free to all the world; that, moreover, prescription doth not take place in things that cannot be alienated, such as the sea, the use of the sea, and things common to all men: add to this, that the opposition of other nations, and their navigation in that sea would have hindered the prescription.

It is proved in the eighth, that by the law of nations the commerce between nations is free, and cannot be prohibited without injustice.

In the ninth it is shewn that the trade to the Indies doth not belong to the Portuguese, exclusive of other kingdoms, because they first took possession of it, since the title of first occupant takes place only in that which is corporeal.

The tenth proves, that the Pope could not grant the Portuguese an exclusive trade to the Indies: the eleventh, that this trade does not belong to them by prescription: the twelfth, that nothing is more unjust than the claim to an exclusive trade set up by the Portuguese.

The author concludes his work with the thirteenth chapter, exhorting the Dutch to continue their trade to the Indies in time of war, of truce, or of peace.
This work was printed without Grotius's knowledge, and published without his consent.