"[S]o with my Eyes open, and with my Conscience, as I may say, awake, I sinn'd, knowing it to be a Sin, but having no Power to resist; when this had thus made a Hole in my Heart, and I was come to such a height, as to transgress against the Light of my own Conscience, I was then fit for any Wickedness, and Conscience left off speaking, where it found it cou'd not be heard."
— Defoe, Daniel (1660?-1731)
(pp. 50-1, P. 79 in Penguin)
See The Fortunate Mistress: Or, A History of the Life and Vast Variety of Fortunes of Mademoiselle de Beleau, afterwards call'd the Countess de Wintselsheim, in Germany. Being the Person known by the Name of the Lady Roxana, in the Time of King Charles II (London: Printed for T. Warner, 1724). <Link to ESTC><Link to Google Books>
Reading Daniel Defoe, Roxana, ed. David Blewett (New York: Penguin Books, 1987).