Truth is one of the major moral principles for Augustine, so when comparing it with other values, he places it in top priority. According to his definition, lie is a conscious statement of erroneous nature. When discussing lies, Augustine points out that not every false statement can be classified as lies because falsehood can stem from wrong thinking, wrong information provided by another person or delusion created by emotion. Thus, when a person makes a mistake, this is not lies in every case because unconscious lies are falsehood. At the same time, speaking about moral estimation of lying, Augustine claims that even if lies are conscious, they are not derogatory in all cases. In other words, there are situations when a person can lie out of good motivation and for the sake of a noble deed.
So, there are objective and subjective criteria for determining lies. Objective estimation means comparing reality with the actual statement. Subjective estimation can take into account motivation and intention. If a person believes lies to be true because he is ignorant, he cannot be condemned as he is not willing to break a moral law. “ Now whoever utters which he holds in his mind either as belief or as opinion, even though it be false, he lies not” ( Augustine 384). Thus, a will is one of the main criteria to define lies.
However, if a person knows that he is speaking lies, then two cases are possible and the reason why he lies is taken into consideration. Truth and will can be used as criteria in any combination. Augustine states that will can be even a more crucial factor in determining lies. Even if a person tells the truth in terms of objectivity but his aim is to deceive, than he is a liar. All lies are lies but there are different degrees: “A lie told for lust is worse than a lie told for want, and a lie told for one’s self is worse than a lie told for another.”