In Lord of the Flies, has Simon alone grasped what is wrong on the island?

Ralph and Piggy also notice how the boys are falling out of civilized ways and into barbarism. Piggy continually returns to the conch. He remembers how it had been used to organize the boys and establish reason and order. He clearly sees the danger of losing that order. Shortly before his death, Piggy says

"Which is better—to have rules and agree, or to hunt and kill?"

Roger continues to drop rocks upon them and this symbolizes his answer: that he (Roger) prefers violence to rules. 

Ralph also sees the danger. He echoes Piggy's sentiments.

"Which is better, law and rescue, or hunting and breaking things up?"

In the subsequent paragraph, we have a last image of Piggy, supporting Ralph, still clutching the object that established reason and order: 

By him stood Piggy still holding out the talisman, the fragile, shining beauty of the shell. 

Piggy and the shell are destroyed together. Democracy, reason and order are also destroyed. 

Simon is the most intuitive boy on the island. So, one could argue that he is the first boy to become aware of the potentially dangerous slide into savagery. At the end of Chapter 8, Simon speaks to the Beast. The hallucination (from Simon's own mind) acknowledges that Simon had always known this potential dark side of the boys: 

You knew, didn’t you? I’m part of you? Close, close, close! I’m the reason why it’s no go? Why things are what they are?