Who bears the burden of proof on negligence?

By the order n. 6792 of 14 March 2014, the Supreme Court of Cassation has clarified that the judgment regarding the non-performance of a professional activity consists of two steps: the first relates to the performance of the professional activity, the second to having performed the professional activity in accordance with the rules of diligence prescribed by the nature of the performance. In the event of a no performance being pleaded, it is not for the debtor to prove that he has acted with diligence, but for the creditor.