The portrayal of Charles Darnay's eyes as dark seems to imply that he probably has a secret within. Also, when his condition in the courtroom is described to be like that of a young gentleman, it seems like he was very elegant. He is considered to be well bred when he is described as "well-grown". Also, he is seen to be immaculate by the way he ties his hair. It appears like he does want to show that he does not care about himself or the way he looks. Overall, the physical description of Darnay makes him appear to be sophisticated and very cultured.
It was a hard matter to preserve the innocent deceit of which they were profoundly unsuspicious. But, an affectionate glance at his wife, so happy and busy, made him resolute not to tell her what impended (he had been half-moved to do it, so strange it was to him to act in anything without her quiet aid), and the day passed quickly away. Early in the evening he embraced her, and her scarcely less dear namesake, pretending he would return by and by (an imaginary engagement took him out, and he had secreted a valise of clothes ready), and so he emerged into the heavy mist of the heavy street, with a heavier heart" (p. 242). The fact that he felt strange not telling Lucie about what he was going to do shows how honest he was before, towards her. Additionally, the embrace he made to Lucie displays his love for her along with the "heavier heart" he had when he left the family for Paris.
Charles Darnay appears to be a good man due to his actions. He is seen as a cultured, poised and dignified man just by the way he stands in the courtroom. He proves his courage in his decision to return to Paris at great personal risk to save the imprisoned Gabelle. He also shows his sense of responsibility when he tries to help his old family servant. Darnay was used to Lucie's quiet aid in anything he did which means that he tried not to hide anything from her. This shows his honest behavior. Also, when Darnay embraces his wife and later emerged "into the heavy mist of the heavy street, with a heavier heart", he appears to be guilty of not telling Lucie about what he was going to do. It also displays his intense love for her.
Darnay, though a French aristocrat by birth displays great virtue when he renounces his uncle's property in front of his uncle, Marquis Evrémonde. It shows that he was aware of the pain his family was inflicting to the poor which is why after the death of his uncle, he starts his life over by becoming a French tutor. Charles exhibits an admirable honesty in his decision to reveal to Doctor Manette his true identity as a member of the infamous Evrémonde family before he marries Lucie. The way Darnay talks itself shows that he was a well-bred man and that he thought carefully before saying what he wanted to say. One example of this was when he apologizes to Carton for the distress Lucie experienced in the courtroom. He even asks him to send his "fervent acknowledgements" to her. In conclusion, Darnay displays his honesty and sophistication by his speech. His speech also shows great virtue when he rejects the cruel values of his uncle.
"The intention with which he had done what he had done, even although he had left it incompleted, presented it before him in an aspect that would be gratefully acknowledged in France on his presenting himself to assert it. Then, that glorious vision of doing good, which is so often the sanguine mirage of so many good minds, arose before him, and he even saw himself in the illusion with some influence to guide this raging Revolution that was running so fearfully wild" (p. 240). This thought shows that Darnay did not feel any danger when he decided to go to Paris. Instead, he thought that when he asserts his renunciation of his family's title, he would be gratefully acknowledged in France.
Hence, Charles thought that going to Paris to save his old family Servant was the right thing to do as the only crime that the old servant committed was "fidelity to himself and his family". They were an honorable set of reflections as he felt obliged to do his moral duty. After he made the decision to go to Paris, he thought about how he would be "gratefully acknowledged" by renouncing his family's title publicly. He went so on to think that after doing good, he might eventually be able to guide the Revolution itself. This shows that he thought of no danger of going back to Paris. However, we see later that he in fact was arrested in revolutionary France, and tried twice. Additionally, the uneasiness he felt when he thought about his old servant was arrested shows that he still feels responsible and perhaps guilty of the arrest.