In A Tale of Two Cities, Book 3, why does Dr. Manette think he can save Charles Darnay in Chapter 2?
Hang on a minute! You have asked several questions and enotes specifies that you only ask ONE. I have edited your question accordingly and will respond to your first alone. Dr. Manette, in returning to Paris at this point now that the Revolution has begun, actually finds himself as something of a hero. Certainly the key theme of resurrection and being "recalled to life" is true here because Dr. Manette has been transformed in terms of his influence. Consider what he says to Mr. Lorry:
"My dear friend, I have a charmed life in this city. I have been a Bastille prisoner. There is no patriot in Paris - in Paris? In France - who, knowing me to have been a prisoner in the Bastille, would touch me, except to overwhelm me with embraces, or carry me in triumph. My old pain has given me a power that has brought us through the barrier, and gained us news of Charles here..."
It is this new standing and respect that Dr. Manette has gained because of his 18 years imprisonment that convinces him that he is able to help liberate his son-in-law from jail, which proves to be true - but only up to a certain point. The tremendous and crushing irony in this tale is of course that it is the high respect that Dr. Manette commands that will actually be used to condemn Charles Darnay.
in chapter 11, when carton says to lucie "a life you love" he means that she is going to live the life she loves with darnay because he is going to take darnays place and sacrifice his life so that lucie can have the life she loves with darnay.
hope this helped :)
in charles darnay's trial (if you mean the first trail):
he was arrested for treason and usually, in that time , these cases were settled in favour of the kings. so somehow Charles Darnay expected he will be found guilty. after the testimony of some witnesses, sydney carton passed a note to mr. stryver while the later was questioning an unknown wittness. mr styver then asked the wittness if he was sure it was the prisoner who he had seen, then he pointed to sydeny carton and that was the turning point in the trail, since sydeney carton and charles darnay looked exaclty similar. afterwards charles darnay was aqquitted.
i hope i had helped
(sorry for not answering the rest of the questions, this was the one i know.... i'm still studying the novel)