Sentence:  To adulterous lust the most sacred duties are sacrificed, because, before marriage, men, by a promiscuous <WSD>intimacy</WSD> with women, learned to consider love as a selfish gratification—learned to separate it not only from esteem, but from the affection merely built on habit, which mixes a little humanity with it. 
Meaning of the word marked with <WSD> tags:  Feeling or atmosphere of closeness and openness towards someone else, not necessarily involving sexuality.