Question 110 — Lying

We must now consider the vices opposed to truth, and (1) lying: (2) dissimulation or hypocrisy: (3) boasting and the opposite vice. Concerning lying there are four points of inquiry:

(1) Whether lying, as containing falsehood, is always opposed to truth?

• (2) Of the species of lying;
• (3) Whether lying is always a sin?
• (4) Whether it is always a mortal sin?