Leah’s concept of justice is practical and political. Her ideals at Bikoki Station are mostly centred around the Congolese people being free of US interference. When she was a child, Leah fought for permission to hunt with the men, and then had to fight again when they tried to stop her from taking her fair share of the kill. For Leah, autonomy and self-determination are necessary for justice. The full sentence of the quote is: “I don’t have much left of my childhood beliefs I can love or trust, but I still know what justice is,” referring to how Leah abandoned the fundamentalist Christian beliefs drilled into her by her father and has maintained only her sense of justice throughout her life.
Leah’s twin sister, Adah Price, develops a more holistic and philosophical idea of justice. Adah has survived childhood trauma, including before birth, and her conception of justice as a child is cynical, at times almost cruel. But after her mother chooses to save her and escape, Adah studies medicine, makes some physical recovery from her ailments, and decides that the existence of an absolute right and wrong cannot be reconciled with her understanding of science.
Rachel can be described as having a white supremacist concept of justice. Rachel believes that she is entitled to all she has by virtue of being a white woman “surviving” in Africa. Rachel admits to herself that she makes money from men who are destroying Africa but believes that anybody else would be doing what she is, so she is justified in doing so. Rachel also has a view of justice wherein any perceived slight against her is permission to take as much as she can from who she believes has wronged her. We can see this in her mistreatment of the servants at her hotel.

There are various types of justice at play in this novel. Leah, of course, is referring to political and social justice when she makes this statement. When she says she knows what justice is, she only thinks she knows. By the end of the novel, she is stating that there IS no justice in the world because in her life, she has mostly seen injustice, especially with regard to her husband, who has always sought after justice for his family and his country.

Leah has married a Congolese school teacher whose concept of justice she has learned over the years is very different from what her own used to be. As her husband Anatole patiently teaches her about how he sees justice, she slowly comes to accept his version because it seems more correct to her. Children should not die of starvation, governments should prevent disease, she should be allowed to hunt with the men if she is as good a shot, she should be given her share of the meat that she has killed in spite of the fact that she has shown-up the men, her husband should not be kept in jail for years with no charges, her father should not treat her mother with such contempt, her father should work with the Congolese and not against them, she and her sisters should help protect Nelson from snakes and not leave him to sleep in the chicken coop all by himself - on and on and on -- it is a very complicated story.

Each person in the Price family has his or her own version of what justice is. Nathan Price is his own form of justice, even though he believes he is carrying out God's justice. He is mostly apolitical with regard to the various Congolese governments that come and go, caring more about their religion than their politics. Orleanna Price also only pays attention to what is going on in the Congo politically when it affects her own family. She lives in fear of her husband, but exacts her own form of social justice when his stubbornness indirectly leads to the death of her daughter Ruth May. When Orleanna has the choice to save either Ruth May or Adah, however, she chooses Ruth May, explaining to Adah years later her concept of justice at the time was to save the girls "from the bottom up." Ruth May was the youngest at the time, so she was saved in the flood.

Rachel is only concerned with justice as it applies to herself, both as a child and as a grown woman. She goes from husband to husband, trying to get the most she can out of each one of them. She pays no attention to social or political issues. Adah is concerned with social and political justice, but after she becomes a doctor, she slowly learns that justice is not so black and white.

Is it justice for families like the Price family to reign supreme in the Congo? Is colonization just? Should one culture force its values on another?

Read more about this very complex novel here on eNotes.