If there are lies, which is their limit in relation to truth? Out of real problems that he was facing at the time, related the religious heresies and conflicts, Saint Augustine supplies insights on the subject in two texts “On Lie” (De Mendacium) and “Against Lie” (Contra Mendacium). There are good reasons to believe that his concern with the subject was recurrent, since the two texts are practically identical. Without pretensions to define what truth is, the bishop of Hippona applies his negative method to create a tipology of existing kinds of lies. Thus, he evidences a almost completely forgotten fact nowadays: beyond the diversity of species of lie, if something is not true, it only can be false
