Whether one can, without a mortal sin, deny the truth which would lead to one's condemnation?

❌ Objection 1 : It would seem one can, without a mortal sin, deny the truth which would lead to one's condemnation. For Chrysostom says (Hom. xxxi super Ep. ad Heb.): "I do not say that you should lay bare your guilt publicly, nor accuse yourself before others." Now if the accused were to confess the truth in court, he would lay bare his guilt and be his own accuser. Therefore he is not bound to tell the truth: and so he does not sin mortally if he tell a lie in court.

❌ Objection 2 : Further, just as it is an officious lie when one tells a lie in order to rescue another man from death, so is it an officious lie when one tells a lie in order to free oneself from death, since one is more bound towards oneself than towards another. Now an officious lie is considered not a mortal but a venial sin. Therefore if the accused denies the truth in court, in order to escape death, he does not sin mortally.

❌ Objection 3 : Further, every mortal sin is contrary to charity, as stated above (Question [24], Article [12]). But that the accused lie by denying himself to be guilty of the crime laid to his charge is not contrary to charity, neither as regards the love we owe God, nor as to the love due to our neighbor. Therefore such a lie is not a mortal sin.