You must do to others as you would have them do to you.

The Catholic Answers

That cannot apply in matters of conscience. If so, I could say, “Well now, if I were a murderer I would like him to help me to strangle that man. And since he is a murderer, I must do to him as I would like him to do to me in similar circumstances, and help him to strangle his victim.” That is absurd. In all matters where we can do it with a good conscience we must do to others as we would have them do to us. In any case, we Catholics do not wish any Protestant to violate his conscience and offend God in order to please us.

Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty