Too late, too late, your love gave me life. Here am I, the creature you made through your loving; by your passion you created the thing that I am. Who are you to deny me the right to love? But for you, I need never have known existence.
This conversation takes place after it has been revealed to Stephen's mother that she has written love letters to her married female neighbor. Her mother is furious, and made more angry by Stephen's insistence that she loves a woman the same way in which her mother loves her father. Her mother feels that comparing their feelings of love is almost a blasphemy against love. These words are Stephen's plea to her mother to accept who she is and whom she loves.
She also observes that she never asked to come into the world; her mother does not have the right to tell her who to love, or how to love. The result of her love is a person whom she cannot seem to tolerate and whom she believes to be aberrant, so given that her love for Stephen's father produced a person she will not accept, she is giving up her right to tell Stephen about love at all. The plea falls on deaf ears; the two remain estranged and Stephen's mother is cold and distant for the entirety of her daughter's life.
Then Stephen must tell her the cruel truth; she must say, "I am one of those whom God marked on the forehead. Like Cain, I am marked and blemished, and if you come to me, Mary, the world will abhor you, will persecute you, will call you unclean. Our love maybe faithful even unto death, and beyond - yet, the world will call it unclean."
Stephen is very much in love with Mary, and wants to be with her, but she also understands the implications of doing so for her, and in an act of incredible unselfish love, pushes her into a heterosexual relationship in order to try to make her passage through life easier.
Her references in speaking with Mary and explaining their situation are interesting in that they contain a great deal of religious connotation and reference; Hall herself was a devout Christian and deeply upset when her piety was called into question because of her sexual orientation. She uses the orthodox term of "unclean" to describe society's view of lesbianism, and the way in which being known to be in a same-sex relationship would negatively impact Mary's life. She would be ostracized socially, because of the "mark" that Stephen mentions, in this case, that of a homosexual.
For the sooner the world came to realize that fine brains very frequently went with inversion, the sooner it would have to withdraw its ban.
Stephen has studied the subject of inversion thanks in large part to discovering her father's secret bookcase and copious notes on the subject. The discussion stems also from the fact that during the war, many inverts had been called upon to act as ambulance drivers, stretcher bearers and to otherwise take on the more physical non-combat roles taken in peace time by men. Yet, after the war, they went quickly from being respected and rewarded to being ostracized again; society decided when it wanted to accept inverts and when it did not, and more often than not, inverts were viewed with hate, especially when they were not considered useful to the government.
The same can be said of intelligence, because studies proved that many inverts were actually in the top percentile of intelligence and I.Q. Stephen believes that this should be publicized more widely because if the nation knew this, then inverts would surely be accepted again, and treated as valuable contributors to society rather than banned from it.