In the Policraticus especially, but also in his other works, the foundations and provisions of his moral system are found.  He has no distinction to draw in Ethics between theology and philosophy, but uses Scripture and observation alike, though Scripture always in the final appeal.  Of philosophizing, the one final aim, as also of existence, is Happiness; the question, of questions, how it is to be attained.  Happiness is not pleasure, nor possession, nor honour, but consists in following the path of virtue.  Virtue is to be understood from the constitution of human nature.  In man, there is a lower and a higher faculty of Desire; or, otherwise expressed, there are the various affections that have their roots in sense and centre in self-love or the desire of self-preservation, and there is also a natural love of justice implanted from the beginning.  In proportion as the appetitus justi, which consists in will, gains upon the appetitus commodi, men become more worthy of a larger happiness.  Self-love rules in man, so long as he is in the natural state of sin; if, amid great conflict and by divine help, the higher affection gains the upper hand, the state of true virtue, which is identical with the theoretic state of belief, and also of pure love to God and man, is reached.

By the middle of the thirteenth century, the schoolmen had before them the whole works of Aristotle, obtained from Arabian and other sources.  Whereas, previous to this time, they had comprehended nearly all the subjects of Philosophy under the one name of Dialectics or Logic, always reserving, however, Ethics to Theology, they were now made aware of the ancient division of the sciences, and of what had been accomplished in each.  The effect, both in respect of form and of subject-matter, was soon apparent in such compilations or more independent works as they were able to produce after their commentaries on the Aristotelian text.  But in Ethics, the nature of the subject demanded of men in their position a less entire submission to the doctrines of the pagan philosopher; and here accordingly they clung to the traditional theological treatment.  If they were commenting on the Ethics of Aristotle, the Bible was at hand to supply his omissions; if they were setting up a complete moral system, they took little more than the ground-work from him, the rest being Christian ideas and precepts, or fragments borrowed from Platonism and other Greek systems, nearly allied in spirit to their own faith.

This is especially true, as will be seen, of Thomas Aquinas.  His predecessors can be disposed of in a few words.  ALEXANDER of HALES (d. 1245) was almost purely theological.  BONAVENTURA (1221-74) in his double character of rigid Franciscan and mystic, was led far beyond the Aristotelian Ethics.  The mean between excess and defect is a very good rule for the affairs of life, but the true Christian is bound besides to works of supererogation:  first