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:

A1 Whether lying, as containing falsehood, is always opposed to truth?

A2 Of the species of lying;

A3 Whether lying is always a sin?

A4 Whether it is always a mortal sin?