Thomas Aquinas,
Summa Theologiae — Question 100 - ON SIMONY…
“ To be deprived of what one has received is not only the punishment of a sin, but is also sometimes the effect of acquiring unjustly, as when one buys a thing of a person who cannot sell it. Wherefore if a man, knowingly and spontaneously, receives Orders or an ecclesiastical benefice simoniacally, not only is he deprived of what he has received, by forfeiting the exercise of his order, and resigning the benefice and the fruits acquired therefrom, but also in addition to this he is punished by being marked with infamy. ”
