The theme of this volume is the idea of ​​a double soul of the law: the legal judgment always incorporates feedbacks of material justice and therefore is not limited to the application of legislative formulas. The author's experience suggests that those valuations are not pre-judgments to avoid or abusive influences from which the good lawyer should protect himself, but they are essential components of law. As such they must be cultivated openly, with the understanding that, in this way,  the authentic dualist structure of law is restoring itself, a structure that positivist reductions have long obscured. A dualism reflected par excellence in the judicial use of Constitution. Here, the component of material justice of the law is manifested by evidence. It is painted a figure of a judge and a lawyer that is quite different from that of the pure technician of laws: the new figure, indeed ancient, of a responsible agent for the culture of his time.