'The Accursed' is very much a novel about social injustice as the consequence of the terrible, tragic division of classes - the exploitation not only of poor and immigrant workers but of their young children in factories and mills - and as the consequence of race hatred in the aftermath of the Civil War and the freeing of the slaves.
If you're saddened by another's sorrow, then sorrow will never come to you. If you are happy at another's joy then joy will never leave you.