when Sa'd b. 'Abdillah al-Qummi asked him the reason why people cannot elect an Imam for themselves, replied, 'Would he be a righteous man or a corrupt man?' I said, 'Righteous.' He said, 'Is it possible that the selected individual be actually corrupt, for no one really knows what passes through another's mind, in terms of their righteousness or corruption?' I said, 'Yes'. He said, 'That is the reason why.'