How would you describe the themes of guilt, justice and lies within the novel "And Then There Were None" by Agatha Christie?

Agatha Christie wove several themes and motifs throughout And Then There Were None, and certainly the idea of justice, guilt, and lies permeates the entire story.
Judge Wargrave establishes himself as judge, jury, and executioner of the others on Indian Island. Each person on the island has committed a murder, so in one respect their deaths could be seen as a kind of justice. However the larger question is whether Wargrave had the right to promote himself to this position. Part of the problem lies in the moral choice of what constitutes murder. Emily Brent technically did not kill Beatrice Taylor. Should she receive the death penalty? Agatha Christie examines whether or not enforcing justice really makes someone good, or if unjust actions really make someone bad.
Christie also looks at what effect guilt has on a person’s conscience. No matter how dismissive someone may be in public about a situation, privately guilt may be plaguing them. Dr. Armstrong flatly denied any wrongdoing during the surgery he performed, yet he has nightmares about the woman who died in his care. The general brushes off the accusation about murdering his wife’s lover. But by the next day he is so overcome with guilt that he waits for his execution.
Interestingly, characters who admit their crimes feel less guilty. Marston never denies he ran over two young children. Lombard freely confesses he left men to die in Africa, and even says he would do so again in the same circumstances.
Lies abound throughout the novel. Of course murderers are liars, but so are seemingly righteous judges. Christie seems to imply that everyone lies at some point for some reason. Some characters lie to themselves to justify their actions; some lie to others to appear innocent of the accusations. The judge, who has decided he is the most moral of the group and has the right to judge and execute the others, lies the most of all.
“And Then There Were None” is a wonderful Christie classic because of the way she integrated a clever plot with meaningful themes.