Humans value some things more than others. Survival is the bedrock human value (yourself, your family, your children, your species). Followed by things like pleasure and the lives of others and the lives of animals. Every human weighs the things a little differently, and we're all bad at the math. But on average most humans weigh the important things about the same. There is a reason Elizer is able to keep going back to the example of saving a child.