Ah I see. Well, I suggest 'The Immoralist', and also books by Dostoevsky, particularly 'Crime and Punishment' and 'The Brothers Karamazov'. However it might be difficult to get at the true nature of his meaning if you are not familiar with some of the nuances of English. However, if you can read Les Miserables, I am sure you will be perfectly able to understand him.
Also, I recommend 'The Master and Margharita' and a few of Kafka's short stories, in particular 'The Trial'.