Because he doesn't like him
Its sort of a Logic and Intelligence(Piggy) vs. Bloodlust and Savaregy(Jack) thing that Golding might've thought of.
Basically Jack wants to have power and be the leader. At a time when he feels that he has just proven his prowness as a hunter Ralph has reasserted his own leadships over the incident of letting the fire out. Jack has already punched Piggy, who he dislikes but also sees as an easy target and a way of getting at Ralph. Jack then refuses to give Piggy any meat as a further display of his own power. Jack killed the pig and Jack chooses who eats it, not Ralph.
Jack's character is symbolic of society in the novel. He is unable to kill because he alone still retains his humanity.
Another answer: Jack was initially unable to kill the piglet in Lord of the Flies because he was an English schoolboy who was the head boy in a choir and he had probably never had to kill anything before in his life. It is easy to say, 'I will kill a pig' it is a different matter to be confronted with a terrified squealing animal and be faced with the prospect of plunging your knife into its living flesh. Understandably Jack flinched. Feeling embarrassed by his failure to kill the piglet Jack vowed that next time he would kill. Jack then became positively obsessed with the idea of hunting and killing pigs. Far from being alone in maintaining his humanity Jack actively went out iof his way to kill. It also became obvious from his comments and his reaction to the deaths of Simon and Piggy, and his hunting of Ralph, that killing was what was important to him, not the pigs.
Jack does not kill the piglet in chapter one because he is just a boy. He was the head boy in a choir, he probably came from a priviledged background, and had never had to kill anything before in his life. It is one thing to say "I will a pig" but it is another thing entirely to stab a squealing terrified young animal to death, to feel the knife slicing through living flesh. It is hardly surprising that in those circumstances Jack baulked and failed to stab the piglet.
Jack was the head boy of a choir. He had probably never had to kill anything before in his entire life. It is quite easy to say that you will kill something but it is a different matter to actually do it. When confronted with a terrified squealing piglet Jack baulked at the thought of plunging a knife into it's living flesh, which is hardly surprising.
because he really feels sorru for him, its a metaphor showing how the sea and land take mercy of the human, or how human takes mercy of natural environment due to the help it has provided. Nevertheless, given he NEEDS to do it, he kills piglet like human destroys environment
He was choosing a place, he was waiting a moment to decide where to stab it
Jack is one of the characters in the story "Lord of the Flies", by William Golding. He was unable to kill the pig because of the moral propriety that society instilled in him.
with a spear.
Jack draws his knife, apparently intending to kill the piglet. But, crucially he hesitates and the piglet struggles free and escape. Seeing the questioning look on the faces of Ralph and Simon Jack explains that he was choosing a spot to stab the piglet. In reality the enormity of actually plunging a knife into a squealing terrified animal caused him, quite understandably, to hesitate Jack however is ashamed that the others might think that he is weak and makes a point of stressing that next time he won't hesitate
Jack draws his knife, apparently intending to kill the piglet. But, crucially he hesitates and the piglet struggles free and escape. Seeing the questioning look on the faces of Ralph and Simon Jack explains that he was choosing a spot to stab the piglet. In reality the enormity of actually plunging a knife into a squealing terrified animal caused him, quite understandably, to hesitate Jack however is ashamed that the others might think that he is weak and makes a point of stressing that next time he won't hesitate
Jack hesitates because, although it is easy to say that you will kill something, as a well brought up schoolboy he has never before been faced with the prospect of plunging a knife into living flesh. The terrified squealling of the piglet and the thought of actually taking its life caused Jack to hessitate and the piglet managed to escape. Jack later said, to quote directly from the book, "I was choosing a place. Next time----!" He snatched his knife out of the sheath and slammed it into a tree trunk. Next time there would be no mercy.
Samneric
to kill the pig
Jack draws his knife, apparently intending to kill the piglet. But, crucially he hesitates and the piglet struggles free and escape. Seeing the questioning look on the faces of Ralph and Simon Jack explains that he was choosing a spot to stab the piglet. In reality the enormity of actually plunging a knife into a squealing terrified animal caused him, quite understandably, to hesitate Jack however is ashamed that the others might think that he is weak and makes a point of stressing that next time he won't hesitate
Because he is not completely savage yet, and is momentarily constrained by the ethical and moral constraints of the soceity. However, soon after, the strings snap and he becomes one of the "beasts" in Golding's novel. Check this out for more info - http://www.sparknotes.com/lit/flies/
Jack draws his knife, apparently intending to kill the piglet. But, crucially he hesitates and the piglet struggles free and escape. Seeing the questioning look on the faces of Ralph and Simon Jack explains that he was choosing a spot to stab the piglet. In reality the enormity of actually plunging a knife into a squealing terrified animal caused him, quite understandably, to hesitate Jack however is ashamed that the others might think that he is weak and makes a point of stressing that next time he won't hesitate
Jack promises not to kill the piglet but make a spear to hunt and kill a real pig instead. Despite his promise, he ends up killing the piglet when the opportunity arises.
Jack hesitates because, although it is easy to say that you will kill something, as a well brought up schoolboy he has never before been faced with the prospect of plunging a knife into living flesh. The terrified squealling of the piglet and the thought of actually taking its life caused Jack to hessitate and the piglet managed to escape. Jack later said, to quote directly from the book, "I was choosing a place. Next time----!" He snatched his knife out of the sheath and slammed it into a tree trunk. Next time there would be no mercy.
Jack doesn't kill the trapped piglet because he wants to continue hunting and believes that a live pig would provide more excitement and challenge. Additionally, Jack may not see the trapped piglet as a worthy target for his aggression.
The piglet escapes the creeper vines because as it struggles, Simon frees it inadvertently. This event symbolizes Simon's kindness and connection to nature, contrasting with the violence and savagery exhibited by the other boys on the island.
In chapter 1 of Lord of the Flies, Jack does not kill the pig with his knife because he's still innocent at this point in the book and cannot bear to actually cut into living flesh. However, as time proceeds, Jack adopts a much more savage personality.
NO
The reader learns that Jack has a violent way of dealing with things when he slashed the green candle buds. Later when Jack tries to kill the piglet for the first time he finds he doesn't have the heart to kill it.
Jack hesitated to kill the piglet because he was not used to the idea of taking a life. He was still conflicted by moral values and societal norms. Additionally, the innocence of the piglet and the emotional impact of killing it made Jack hesitant to follow through with the act.
Ralph