Now there are more difficult cases, but even in these I tend to side with Augustine, whose argument here, to the best of my understanding, leaves no room for social lying, though he clearly struggles with lying for some greater good, such as saving a life:
http://www.newadvent.org/fathers/1312.htm
In particular see here his overall conclusion:
42. It clearly appears then, all being discussed, that those testimonies of Scripture have none other meaning than that we must never at all tell a lie: seeing that not any examples of lies, worthy of imitation, are found in the manners and actions of the Saints, as regards those Scriptures which are referred to no figurative signification, such as is the history in the Acts of the Apostles.
Note that even in the hard case of protecting a human life he presents an example of a church leader, Firmus, who both refused to betray a person he was protecting from Rome, and yet refused to lie to protect himself from harm in the process, and in so doing showed himself to be a person of remarkable honor. See paragraph 23.
And I am further reminded of Corrie Ten Boom's sister, Betsie, who rather than lie to Nazis who came to their home looking for Jews, acted wildly and told them the truth, that they were indeed hiding Jews, but her wildness convinced the soldiers she was insane, and they left the home without looking under the trap door, where indeed Jews were hiding.
So there is Providence to consider. What if God has calculated all possible outcomes and determined that the best possible result will come from us always telling the truth? At a certain point we have to trust Him rather than our own fear of immediate consequences, reverencing God, not primarily by how we do religious ceremony, but by how we live our lives:
Eph 4:24-25 And that ye put on the new man, which after God is created in righteousness and true holiness. Wherefore putting away lying, speak every man truth with his neighbour: for we are members one of another.
Peace,
SR
How does one handle: "Does this dress make me look fat?"