See Augustine, The City of God, l. i. c. 16-18. He treats the subject with remarkable accuracy: and after admitting that there cannot be any crime where there is no consent, he adds,
Sed quia non solum quod ad dolorem, verum
etiam quod ad libidinem, pertinet, in corpore alieno
perpetrari potest; quicquid tale factum fuerit, etsi
retentam constantissimo animo pudicitiam non excutit,
pudorem tamen incutit, ne credatur factum cum mentis etiam
voluntate, quod fieri fortasse sine carnis aliqua voluptate
non potuit.
In c. 18 he makes some curious distinctions between moral and physical virginity.