1.If you respond to counterclaims, you appear unbiased (and, therefore, you earn the respect of your readers). You may even want to include several counterclaims to show that you have thoroughly researched the topic.
2.A reader should stay calm and keep his/her cool because when it comes to an argument ther is a big possibility that you will loose on the argument that you are having if you loose your cool they may think your insane or a mad dog.
