The same applies to the notion of Fraternity which they found on the love of common interest or, beyond all philosophies and religions, on the mere notion of humanity, thus embracing with an equal love and tolerance all human beings and their miseries, whether these are intellectual, moral, or physical and temporal.
But Catholic doctrine tells us that the primary duty of charity does not lie in the toleration of false ideas, however sincere they may be, nor in the theoretical or practical indifference towards the errors and vices in which we see our brethren plunged, but in the zeal for their intellectual and moral improvement as well as for their material well-being.
Catholic doctrine further tells us that love for our neighbor flows from our love for God, Who is Father to all, and goal of the whole human family; and in Jesus Christ whose members we are, to the point that in doing good to others we are doing good to Jesus Christ Himself. Any other kind of love is sheer illusion, sterile and fleeting.
Excerpt from Notre Charge Apostolique by Pope Saint Pius X.