Why does jean valjean reveal his true identity in Les Miserables even thought it means he must go back to prison?

In Les Miserables, Jean Valjean reveals his true identity because if he does not, an innocent man (who looks very much like him and has been arrested as Jean Valjean) will be sent to prison for past crimes that he did not commit. Valjean weighs the pros and concs of confessing his true identity in the song "Who Am I?" While he recognizes and regrets the fact that all the workers in his factory will be abandoned, and also (in the book moreso than the play/movie) that Fantine in her child might not be able to be protected by him any longer, he faces the fact that he cannot live with himself if he willingly allows an innocent man to go to prison in his place ("How can I ever face my fellow men? How can I ever face myself again?").