 During their departure part of the town was destroyed by fire.In 1522 in Grudziądz, Nicolaus Copernicus, who aside from his astronomical work was also an economist, presented his treatise "Monetae cudendae ratio", in which he postulated the principle that "bad money drives out good" (also known as the Gresham's law or the Gresham–Copernicus law) and included an early version of the quantity theory of money – a key concept in economics.Following Protestant Reformation, in 1569 the local Protestants were given access to the Holy Spirit Church; in 1572 Catholicism seemed to have vanished almost entirely in the town.