Whether lying is always opposed to truth?

Objections

Objection 1 : It seems that lying is not always opposed to truth. For opposites are incompatible with one another. But lying is compatible with truth, since that speaks the truth, thinking it to be false, lies, according to Augustine (Lib. De Mendac. iii). Therefore lying is not opposed to truth.
Objection 2 : Further, the virtue of truth applies not only to words but also to deeds, since according to the Philosopher (Ethic. iv, 7) by this virtue one tells the truth both in one's speech and in one's life. But lying applies only to words, for Augustine says (Contra Mend. xii) that "a lie is a false signification by words." Accordingly, it seems that lying is not directly opposed to the virtue of truth.
Objection 3 : Further, Augustine says (Lib. De Mendac. iii) that the "liar's sin is the desire to deceive." But this is not opposed to truth, but rather to benevolence or justice. Therefore lying is not opposed to truth.