Here are several roles that Giles Corey serves in The Crucible.
1. He represents the inhabitants of Salem who unwittingly bring harm to their family or neighbors (unlike the Putnams or Abigail who knowingly accuse their enemies or opponents). Example: When Rev. Hale first arrives in town, Giles thinks nothing of talking to Hale about his wife's "reading strange books" or his inability to pray around his wife sometimes. Giles does not tell Hale this information to accuse his wife, he is simply curious and fascinated with the "expert" who as newly come to Salem. Giles's situation is not exclusive. Other characters in the play unknowingly help the court falsely arrest members of the Salem community (Mary Warren makes the poppet for Elizabeth, not knowing that Abigail will use it against Elizabeth. Rev. Hale's questioning of the Proctors helps lead to Elizabeth's arrest, when he most likely wanted to establish that she and John were "good people.").
2. Giles represents a loyal friend and husband. Example: Even though Giles innocently makes suspect comments about his wife, when she is arrested, he does everything in his power to free her and their friends and neighbors. He is so loyal to whoever his informant was (the person who told him that Mr. Putnam was making his daughter accuse specific people so that he could easily get their land) that he goes to his death with that person's name because he knows that the court or Putnam will go after the informant if he snitches. In reality, Giles Corey is pressed to death because he will not give up the name, but in doing so, he ensures that his children get his land because he was not accused of neither did he confess to witchcraft which would have blackened his name permanently.
3. Finally, I think that the most important role that Giles Corey plays is that of a common man demonstrating more common sense than the "learned," all-powerful judges. Example: Giles naively talks about how many times he has been in court, but even Judge Danforth cannot deny the logic behind some of Giles's arguments. Giles is similar to John Proctor in this aspect. While Proctor's character represents that an "imperfect" soul still has the right and sense to cry out against moral injustice, Corey's character illustrates the fact that a high education and obssession for power cannot silence the tenacity of a sensible person who speaks the truth. In the end, Corey establishes the legacy of a strong-willed, simple but honorable man, while the audience views Judge Danforth deservedly as a villain.
In the play "The Crucible" Giles is one of the town elders who is falsely accused of devil's play like the others. He refuses to admit that he has done any wrong doing. He is also John Proctor's friend and someone whom he talks with. Giles is there to demonstrate that even the elderly were not exempt of accusations, especially if they disagreed with the wrong person. Giles is also very outspoken.
"Giles:furious with his fists clenched. "A fart on Thomas Putman, that is what I say to that!"(89)
Giles becomes fed up with the whole business and rushes for Putnam.
Giles, over his shoulder at Putman. "I'll cut your throat Putman, I'll kill you yet."(91)
Giles is put to death by being pressed between a stone. His breath is gone from him.