I never thought I had a right to sacrifice another being to my own good or pleasure; but whatever else ensued you would be placed in circumstances infinitely more favourable to happiness than before.
Source, in full
In a letter to Sabrina Sidney, whom Day attempted to groom into the "perfect wife", explaining his behaviour towards her; as quoted in How to Create the Perfect Wife: The True Story of One Gentleman, Two Orphans and an Experiment to Create the Ideal Woman (2013), Weidenfeld & Nicolson, p. 115