His general principles touching natural law are very solid; but they are too intricate, and it requires deep meditation to unfold them. He does not sufficiently shew the chain of consequences to be deduced from them, and applied to particular subjects; which gave certain authors of little penetration, or candour, occasion to say, that after laying down his principles he makes no use of them, and builds his decisions on a quite different thing. He might have prevented these rash censures by enlarging somewhat more, and pointing out on each head the connection of the proofs he makes use of, with the general principles from whence they are drawn.
With regard to the law of nations, which he considers as an arbitrary law in itself, but acquiring the force of a law by the tacit consent of nations, Barbeyrac observes that in the sense he understands it, and has endeavoured to establish its obligation, it has been shewn to be insufficiently grounded: yet the questions which he builds upon it make a great part of his work.
It has been thought that his style is too concise; that he often expresses himself but by halves; that he supposes many things which require great study, passes over subjects of importance, and handles others which he might have omitted; such as questions relating rather to Divinity, than the science of Natural Law: in fine, it has been said that the desire of shewing his learning hurt him: and a very judicious Magistrate[151] justly observes, that by displaying less learning he would have appeared a greater Philosopher. Notwithstanding all these defects, it is universally acknowledged to be one of the finest works that ever was written.
When this book appeared at Paris, Cardinal Francis Barberin, who resided there as Legate from his uncle Pope Urbin VIII. hearing it much spoken of, was curious to see it; and read it with attention. It is said he was shocked at first that the author, in speaking of the Popes, did not give them the titles which they are wont to receive from Roman Catholic authors; but was otherwise well pleased with the book. The reading of it had been permitted at Rome two years, when on the 4th of February, 1627, it was put into the Index Expurgatorius, with his Apology and Poems[152].