In A Tale of Two Cities, Book II Why does Sydney Carton love Lucie?Charles Dickens's A Tale of Two Cities
In a modern movie entitled, As Good as It Gets, like Helen Hunt's character, Lucie Manette inspires Sydney Carton to "bee a better person." Fair and delicate, like the maids of Camelot, pretty Lucie inspires the dissipated man to become someone better. So inspired by this fair maiden is Sydney that he tells her he is willing to die for her if doing so will ensure her happiness, for sacrificing himself will give his sad life meaning.
In addition to inspiring Sydney to become a better person, Lucie represents the concept of virtue by Dickens as an inactive quality, much like the Calvinist notion of "grace" as something God-given and unattainable. As Lucie suffers passively and bears up under the threats against her family, Carton falls more in love with her, hoping to redeem his sins and the dissolute life he has through a spiritual resurrection.
I think it would be a good idea to refer to René Girard's theory of "mimetic desire". It is assuredly of some relevance here because of the strange relationship that exists between Sydney Carton and Charles Darnay.
As a matter-of-fact, René Girard's interpretation of desire in The Violence and the Sacred rests upon the idea that desire does not really lie either in the subject or in the object but that it imitates another desire. Indeed, the subject models himself after another subject, so that the sense of rivalry turns the desire into an obstacle to be overcome and eventually sought for.
Consequently, in the case of Carton, the frustration is due to his unconscious desire to be other which reveals the desire to be and beyond the lack of being.
Thus, it is his passionate desire and love for Lucie that turns the antagonistic (which largely results from their social positions and the clash of interests it implies) into the agonistic (the exhilaration in spite of or because of the pain, because of the suffering). His love becomes something unparalled, unprecedented, unheard of.
I think This is probably why he loves Lucy.