In The Crucible what are some examples to support that John Proctor seems to be the only voice of reason at the end of Act 2?
1. When they find the poppet with the needle in it, everyone else there automatically jumps to the very illogical and quite ridiculous conclusion that Elizabeth used the doll as some sort of long-distance voodoo curse on Abigail. John is the ONLY one who sees through this. He immediately points out, vocally, the logical conclusion that Mary must have put the needle in the doll, and that Abby must have stabbed herself. He seems to be the only one willing to look at that option, which is the reasonable one.
2. To prove just how reasonable he is and how crazy the others are being, he himself questions Mary about the doll, determining that yes, in fact, she had put the needle there, and that Abby had seen her do it. No one else thought to question Mary, who did, after all, make the poppet. John is the only one who thought to do that. He's so confident that the reasoning is so clear that he turns to everyone else and concludes, "What say you now?" challenging them to dismiss the logic of it.
3. He is the ONLY one who mentions, or even seems to think, that Abby, who is behind all of this scheming, might be up to something. After Elizabeth is arrested, he argues, "Why do you never wonder if Parris be innocent, or Abigail?" He asks them how they can trust the accusers. These are reasonable questions that need to be asked--John is the only one asking them.
I hope that helps; good luck!