 He argues that the term as found in Lucretius and Cicero was internalized by the Catholic Church through Lactantius and Augustine of Hippo.During the Middle Ages it was superseded by the term "faith", which Smith favours by contrast.In the Renaissance, via the Christian Platonist Marsilio Ficino, "religio" becomes popular again, retaining its original emphasis on personal practice, even in John Calvin's "Christianae Religionis Institutio" (1536).