Renaissance (15th century)
Feast: May 10
A Dominican archbishop in Medici-era Florence who wrote the first serious Catholic treatise on business ethics — and lived so simply that he owned almost nothing.
Antoninus Pierozzi was so small and frail when he applied to the Dominicans at fifteen that they sent him away and told him to come back when he had memorized a massive section of canon law. He did it in a year. That combination of modesty and stubbornness defined his whole life. As Archbishop of Florence from 1446 to 1459, he governed one of the wealthiest, most politically tangled cities in Europe during the height of Medici power. He never took a bribe. He lived in a bare cell, ate little, and gave everything else away. After earthquakes and plague hit Florence, he organized relief efforts personally. But his most lasting contribution was intellectual: his Summa Moralis tackled economic ethics with a specificity no theologian had attempted before. He wrote about fair wages, just pricing, the morality of insurance, and the ethics of international trade — questions that mattered urgently in a banking city. He walked through the streets of Florence so often, visiting parishes and checking on the poor, that the people called him 'Antoninus the Counselor.' He died in 1459 and was canonized by Pope Adrian VI.