The correct answer is he believed it was unnecessary for a national government that possessed only specific, delegated powers.
He believed that a government that had only limited specific powers was not necessary since the government would not exploit the people even if they didn't have the bill of rights. Since a tyrannical government can change easily at the next election cycle, then there's no necessity for a bill of rights since anyone infringing upon liberties would be changed after their term or would be impeached.
