The Senate has 315 elected members, and an additional number of appointed life senators and ex officio life senators. Life senators appointed by the President of the Republic "for outstanding merits in social, scientific, artistic and literary fields" have included such names as the orchestral conductor Arturo Toscanini [who rejected his appointment], the poet Eugenio Montale, and the playwright Eduardo De Filippo, to mention but a few. Former Presidents of the Republic are ex officio life senators. The presently serving life senators appointed by the President of the Republic are: Mario Monti, Claudio Abbado, Elena Cattaneo, Renzo Piano and Carlo Rubbia. The former President of the Republic currently sitting in the Senate is Carlo Azeglio Ciampi. The 315 elective seats of the Senate are distributed among the twenty Italian regions in proportion to their population, save for the seats assigned to the Overseas constituency. One seat is assigned to Valle d'Aosta, two to Molise and at least seven seats to each of the other eighteen regions. Under Article 58 of the Italian Constitution, any voter of 40 years of age or over may be elected.