In Lord of the Flies, there is a struggle between compassion, reason, and order with violence, sadism, and absolute power.
Demonstrate the way in which both of these things exist and struggle within humanity.
So are you just asking how these things show up in humanity (not in the novel)? I will assume that you are not asking about examples from the novel.
You can look at any part of human history to find both of these things at work. Look, for example, at the United States' efforts in Iraq and Afghanistan. The United States has spent lots and lots of money and sent so many people (not even counting soldiers) to try to help improve the lives of the people and improve their economies.
Yet, on the other hand, we can see atrocities being committed or instances where the US thinks that killing the "bad guys" is more important than making sure no innocent people die.
You can see such instances of the good and the bad sides of human nature in the history of any country in the world.
Human beings exhibit civilized and uncivilized behaviors in each society. For example: In the book Lord of The Flies Ralph represented compassion, reason, and civilization. Jack represented savagery, violence, and sadism. We live in a world of good and evil. Each day there are people who follow the laws of the moral majority. They go to work, help others, cross the street at crosswalks, share, and demonstrate concern and compassion. There are also criminal elements that exhibit the opposite behaviors. They steal, murder, mutilate, and cause harm others.
On the island the food/meat is the resource that the boys are seeking. Their savagery erupts as civility ebbs away. The resource Jack craves is adoration and power from the tribe. Ralph stands in his way to gain complete total power and must be destroyed. If one looks at the dictator Adolph Hitler, one can see that Hitler also wanted total power. He had his men perform many savage acts to gain complete power. Even now in places like Dafur ethnic cleansing is still occurring because of man's fight for resources and control.
Ralph is the opposite. In our world we have leaders who stand tall for the good. The Danes during the Nazi occupations refused to turn the Jews over to the Nazis.
"The Danes demonstrated through their solidarity, revival of national and spiritual fellowship."
The commitment of the Danes led to the German invasion and spelled disaster for many of their citizens, but they still held fast to their unity and civilized beliefs.