Catholic divines, was undoubtedly constructed, to the full knowledge of its authors, by taking principles of conduct from the system of the Church, and by using the language and methods of jurisprudence for their expression and expansion. While this process went on, it was inevitable that jurisprudence, though merely intended to be the vehicle of thought, should communicate its colour to the thought itself. The tinge received through contact with legal conceptions is perfectly perceptible in the earliest ethical literature of the modern world, and it is evident, I think, that the Law of Contract, based as it is on the complete reciprocity and indissoluble connection of rights and duties, has acted as a wholesome corrective to the predispositions of writers who, if left to themselves, might have exclusively viewed a moral obligation as the public duty of a citizen in the Civitas Dei. But the amount of Roman Law in moral theology becomes sensibly smaller at the time of its cultivation by the great Spanish moralists. Moral theology, developed by the juridical method of doctor commenting on doctor, provided itself with a phraseology of its own, and Aristotelian peculiarities of reasoning and expression, imbibed doubtless in great part from the Disputations on Morals in the academical schools, take the place of that special turn of thought and speech which can never be mistaken by any person conversant with the Roman law. If the credit of the Spanish school of moral theologians had continued, the juridical ingredient in ethical science would have been insignificant, but the use made of their conclusions by the next generation of Roman Catholic writers on these subjects almost entirely destroyed their influence. Moral Theology, degraded into Casuistry, lost all interest for the leaders of European speculation; and the new science of Moral Philosophy, which was entirely in the hands of the Protestants, swerved greatly aside from the path which the moral theologians had followed. The effect was vastly to increase the influence of Roman law on ethical inquiry.