The setting aside of an arbitral award under Article 829 of the Code of Civil Procedure is a form of limited challenge, available exclusively on the basis of one of the procedural defects (vizi in procedendo) listed in Article 829(1) of the Code of Civil Procedure or for breach of the rules of law relating to the merits of the dispute in the cases referred to in Article 829(3) and (4) of the Code of Civil Procedure, and does not give rise to appellate proceedings empowering the court to re-examine the merits of the arbitrators' decision, permitting only a rescinding judgment (iudicium rescindens) consisting of the determination of whether the grounds of nullity provided for in Article 829 of the Code of Civil Procedure are made out.
In proceedings for the setting aside of an arbitral award, lack of reasoning as a defect falling within Article 829(1)(5) of the Code of Civil Procedure, read in conjunction with Article 823(3) of the Code of Civil Procedure, is established only where the reasoning is entirely absent or so deficient as not to permit identification of the ratio of the decision adopted, or where it reveals a course of argument that is wholly unacceptable from a dialectical standpoint, such as to amount to an absence of reasoning.
In arbitration matters, the sanction of nullity provided for in Article 829(1)(11) of the Code of Civil Procedure for an award containing contradictory provisions is to be understood in the sense that such contradictoriness must emerge between the different components of the operative part, or between the reasoning and the operative part, whereas internal contradictoriness between different parts of the reasoning may be relevant as a defect of the award only insofar as it renders it absolutely impossible to reconstruct the logical and legal reasoning underlying the decision on account of the total absence of reasoning referable to its functional model.
In arbitral proceedings, a breach of the right to be heard must be examined not from a formal standpoint but in the context of an inquiry aimed at establishing whether there has been an actual impairment of the opportunity to make submissions and to respond, so that nullity of the award and of the proceedings must be declared only where the challenge, in addition to identifying the defect capable of giving rise to such nullity, specifies the particular prejudice that it has caused to the right of defence.
Lack of standing to be sued (difetto di legittimazione passiva) of the party against whom the claim is brought is a question going to the merits of the dispute and does not constitute the defect of failure to decide on the merits within the meaning of Article 829(1)(10) of the Code of Civil Procedure.