He was a Dominican bishop, best known as a teacher of Saint Thomas Aquinas at the University of Paris. He simply states the reason why private property is to be preferred over that owned by all.
He states: “Everyone is by nature inclined to pay more attention to what is his own than to what is common; so that if this will be better cultivated it will also grow to good fruition where all are concerned; and this advantage is obtained from the fact that possessions are private.”
(as quoted in Odd Langholm, Economics in the Medieval Schools: Wealth, Exchange, Value, Money and Usury According to the Paris Theological Tradition 1200-1350, Leiden: E.J. Brill, 1992, p. 174)