Does Ralph understand why he must be killed? Explain.

Early in the final chapter, Ralph, in hiding, watches the boys as they feast.  He notes that their savagery has increased tremendously.  There is no mistaking their similarity to uncivilized savages. As he thinks about all that has happened, he refuses, at first, to believe that the boys could have purposely become killers.  Then he encounters the skull of the sow that Jack killed and impaled on the stick.  It appears to be grinning at him regards Ralph, "...like one who knows all the answers and won't tell."  Ralph realizes, then, what Simon and Piggy knew - that the real beast, the real source of evil, was inside of each one of them.  He also slowly comes to realize that just as Simon and Piggy died for gaining this insight, he, too, is likely to die.  When he encounters Sam and Eric and they tell him that Jack and the tribe plan to hunt him like a pig and that Roger has sharpened a stick at both ends, Ralph feels even more certain that his fate is to follow Simon and Piggy.  Even though he never articulates the idea as much as Simon or Piggy, Ralph has come to realize that understanding the source of evilness comes with a price and that price is death.  At the end, when he is rescued instead of killed, he weeps for, among other reasons, the loss of innocense.  His realization of the source of evil robs him of ever being innocent again.