Although not physically strong, Piggy is depicted as being surprisingly fearless in the novel Lord of the Flies by William Golding. There are are several moments where he shows his moral courage. For example, although he is shown to be chubby, perspiring, wheezy and short-sighted - most definitely not physically fit and strong - he sticks up for himself verbally and perseveres even when the situation is threatening. Piggy is the one who insists on trying to get the conch back, he is the one who stands up for the littluns and, until he is weakened by the loss of his glasses, stands up for himself and presses his point even when intimidation looms. At first, Ralph thinks similar things, but defers to Jack til he knows better. Piggy has probably learned through being made fun of, that people instil more fear than things.
In Chapter 5, Piggy gives a bit of a speech in which he shows what he thinks about fear.
It is pretty clear that he thinks people fear things that they do not know about. We can see this because he talks about scientific facts and knowledge. He is implying that if you know things, you will not need to be afraid.
He goes on, however, to say that there is one thing to be afraid of. He says that you may need to be afraid of people. This points to a major theme of the book -- that people are inherently somewhat evil.
In the book Lord of the Flies Piggy understands the danger of fear. He knows that the little boys are very frightened about the monster/creature and that they need some solace from their fears. In addition, he is aware that they need to feel safe. Piggy requests an assembly be called to "set things straight."
Jack's response at the littluns fears is to mock them for starting the fears. The littluns cry. Piggy wants to dispel the fears that the little children have so they won't be so afraid and crying and screaming out at night. Piggy is also somewhat sarcastic about the beast being able to hide so well on the island.