Truthfulness or moral truth, so prized by respectable people, is the conformity of our speech to our thoughts. It is the opposite of a lie.

This quality of truthfulness consists in acting in such a manner that our words represent our thoughts faithfully and without equivocation, as we express them to those who have a right to know them and to whom we have a responsibility to reveal them. We do this as a consequence either of a perfect or imperfect obligation to procure for them an advantage that is due them or to avoid causing them an undeserved injury.

In practice, truthfulness us generally referred to as fidelity. It consists in the keeping of promises and contracts in total trust. It is the effect of a willingness of the heart to commit itself and to keep one’s word. It is not allowed, however, to follow a practice contrary to the laws of nature, for in this case the commitment is rendered illicit.