§ 1. On the Nature of Moral Theology

2. Definition. Moral theology can be defined: A science directing human actions according to the law of God, that man may attain his end, that is, eternal life.

It is called, 1. a science: for it is certain and firm knowledge deduced by discourse from certain and immutable principles.

2. directing human actions: by these words its material object is expressed, namely all acts which proceed deliberately from the will of man.

3. according to the law of God: by these words its formal object is designated, namely the conformity to be impressed upon human actions with the divine law; under this name, however, come all laws, insofar as they have the force of obliging from the divine law.

4. that man may attain his end: these words show the supreme end to which all theology is referred.

3. From the aforesaid definition it can at once be gathered how moral theology, according to its nature, is distinguished from all other disciplines which in some way are concerned with the morals of men.

It is distinguished, 1. from dogmatic theology, which discusses faith and divine things universally, in order that it may propose the rules of believing and prove them by fitting arguments; while moral theology itself disputes concerning virtues and vices and sins, in order that it may establish and confirm rules of acting, especially in the internal forum.

2. From ascetical, mystical, and pastoral theology. It belongs to moral theology to measure and define all duties necessarily to be fulfilled by man, and to indicate to him the limit beyond which he cannot pass without incurring the guilt of sin. And hence it is that this sacred science is occupied more with sins than with virtues.

But indeed, the end of theology, both ascetical and mystical, is different: for each discusses much less the sins to be avoided than the virtues to be exercised; each teaches the exercise, motives, and means of Christian perfection itself, yet with this difference, that ascetical theology teaches the ordinary way of perfection, but mystical theology the extraordinary way. But the end also of pastoral theology is different. For this treats of the government of souls, by teaching the pastor how he may withdraw the sheep committed to him from harmful things, direct them to salutary things, and always keep them in the path of virtue, whether these sheep proceed by a slow step through the ordinary and necessary way of salvation, or advance with a greater step in the way of perfection.

3. From the science of canon and civil law; which science hands down rules according to which the Church and civil society are to be governed, while moral theology more generally inquires whether and how much these rules oblige in conscience.

4. From ethics, and indeed both by reason of the principle of knowledge and by reason of the object. For ethics has only one principle of knowledge, and this darkened and weakened, namely the light of reason. But moral theology, besides this slight light of reason, has also another principle, namely the most splendid light of divine revelation, to which there is added besides, as a perfect complement, the infallible magisterium of the Church. It is distinguished also by reason of the object: for this in moral theology extends itself to many more things than in ethics, namely to the supernatural end of man, and to the means by which this end is obtained.