We are going to show a paradox, which emerges from the position of the “radical legalist”. The core of the position is sustained from the conviction that the solution of moral problems consists in the application of legal laws, instead of an analysis of the moral terms. In other words, the moral laws doesn’t exist and, so, the moral terms hasn’t any significance. The position could be more precise: the principle idea is that the moral problems are unsolvable for a rational analysis, postulating that that analysis is impossible for the reason that is denied the existence of any rational law, both strong and weak formulation. The strong formulation of rational morality says that the reason can formulate valid moral laws; the weak formulation defend the idea that we can find an agreement (may be a reasonable agreement, may be not the expression of the reason in a strong sense), if the agreement is possible, then we can trust that there is a solution of the problem, may be not only one, but at least one.