Like many emperors, Marcus spent most of his time addressing matters of law such as petitions and hearing disputes, but unlike many of his predecessors, he was already proficient in imperial administration when he assumed power. He took great care in the theory and practice of legislation. Professional jurists called him 'an emperor most skilled in the law' and 'a most prudent and conscientiously just emperor'. He showed marked interest in three areas of the law: the manumission of slaves, the guardianship of orphans and minors, and the choice of city councillors ("decuriones").