Here is a quote from John Proctor from that scene: “the little crazy children are jangling the keys of the kingdom, and common vengeance writes the law!”
Proctor knows that Abigail is being dishonest, and believes Parris is as well. He wisely suggests that the two of them be questioned rather than assumed to be correct. Proctor is being rational - he is urging that all the details be gathered before prosecution is laid down. Although he has knowledge the others do not, because of his conversation with Abigail in Act I, he is clearly a voice of reason and logic in a time of hysteria. In any such case, prosecutors should slow down and consider all the possible evidence before coming to any conclusion.
Furthermore, Proctor makes the decision to go to court with Mary Warren. He is the voice of reason here because he is willing to fight for both his wife and the principles of justice.