Even in ancient times these similarities were controversial. Non-Christians in the Roman Empire in the early centuries CE, such as Lucian and Celsus, thought Christianity and the mystery cults resembled each other. Reacting to these claims by outsiders, early Christian apologists, such as Justin Martyr, denied that these cults had influenced their religion. The seventeenth-century Protestant scholar Isaac Casaubon brought up the issue again by accusing the Catholic Church of deriving its sacraments from the rituals of the mystery cults. Charles-François Dupuis, in the late eighteenth century, went further by claiming that Christianity itself sprang from the mystery cults. Intensified by religious disputes between Protestants, Catholics, and non-Christians, the controversy has continued to the present day.