"The golden thread that bound them all together"(208)
"The opened half door was opened a little further. A broad ray of light fell into the garret." (35)- Light was let into Doctor Manette’s room. Where the Defarges (dark) had kept him. "Mr. Manette's white head mingled with Lucie's radiant hair, which warmed and lighted it as though it were the light of freedom shining on him." (40) – Representation of light. Helped him become free.
“That dreadful woman seems to throw a shadow on me,"(Lucie said)(331) " But the shadow of the manner of these Defarges was dark upon himself, for an that, and in his secret mind it troubled him greatly.”(331)- Mr. Lorry tries to comfort Lucie after she is faced by Defarge’s shadow in the street. “Madame Defarge gone, like a shadow over the white road.” (345)-snow symbolizing purity and Madame Defarge's darkness/evil. “The night comes dark.” (440) – All of the bad deeds occurred at night.
Light/Dark are the most important/evident dualities. Because Dickens’s is trying to show that in the end light will always overpower over dark. (I.e. the ending. Even though Carton is killed because of the dark Defarge, light has come. And he has died happy and fulfilled. And he even has that glimpse of love with the woman who is also executed) Bad things happen in the dark- Marquis’s house is burned in night, Jerry Cruncher digs up graves in the darkness, Charles's second arrest occurs at night Dickens uses juxtapositions to highlight how bad one of the other things is. I.e. the failure of darkness. To show that it is evil, and how light is good.