Human actions may then be divided, either in regard to the different beings they have for their object, or in regard to the various faculties to which they relate.
The ancients divided morality particularly in reference to the divers human _faculties_, and in private morality they considered above all the _virtues_.
The moderns, on the other hand, have divided morality particularly in its relations to the different _objects_ of our actions; and, in private morality, they have considered, above all, the _duties_.
The ancients reduced all virtues to four principal ones: _prudence_, _temperance_, _courage_, and _justice_. This division was transmitted to us, and it is these four virtues which the catechism teaches under the name of _cardinal_ virtues.
The moderns reduced duties to three classes: the duties towards _ourselves_, towards _others_, and towards _God_. Some add a fourth class, namely, duties towards _animals_.
That portion of morality which treats of the duties towards ourselves, is called _individual_ morality; that which treats of the duties towards God, is called _religious morality_; that which treats of the duties towards other men, _social morality_. As to the duties towards animals, they are of so secondary an order, that it is not worth while to classify them apart; we shall include them in social morality.
Social morality is by far the most extended in precepts and applications, the various relations of men with each other being extremely numerous. It may be subdivided into three parts: 1, general duties of _social_ life, or morality _properly called social_; 2, duties towards the State, or _civil_ morality; 3, duties towards the family, or _domestic_ morality.
We will begin with the study of social morality, social duties towards men in general, and we will first establish their principles and different varieties.
Let us in a few pages rapidly take a summary review of the general principles of _social_ morality.
=18. General principles of social duties: to do good, not to do evil.=--All human actions, in regard to others, may be reduced to these two precepts: 1, to do good to men; 2, not to do them harm. To this all the virtues of social morality may be reduced. But before exhibiting these virtues and vices more in detail, let us explain what is understood by the expressions _to do good_ and _to do evil_.