What is the sum of all the doctrine touching the performance of the works of mercy?
The Apostle has as it were comprised the whole matter in this one saying: Bear (a) one another's burdens: and so you shall fulfill the law of Christ, that is, the law of charity, of which law again he says: (b) If there be any other commandment, it is comprised in this saying, you shall love your neighbor as yourself. And the Apostle St. Peter: (c) Before all things, says he, having mutual charity continually among yourselves: because charity covers the multitude of sins. Which precept, or office of showing mercy or charity, as it is most agreeable to nature and reason: so does it touch even all kinds of men without exception: insomuch as of this we read it written: (d) God has given every man a charge of his nature. And he has given charge in this manner, as Christ interprets: (e) All things whatsoever that you will men to do to you, do you also to them: for this is the Law and the Prophets.
(a) Gal 6
(b) Rom 13; Gal 5
(c) I Pet 4
(d) Ecclus 7
(e) Mat 7; Luk 6
St. Peter Canisius, A Sum of Christian Doctrine, p. 304. I have modernized some spelling and (very slightly) some wording. The Latin is found here, p. 214.