According to Thagard, the behavior of practitioners of a field may also be used for demarcation between science and pseudoscience due to its social dimension in addition to the epistemic one. I defended the tendency of pseudoscientists to commit fallacies, and the number of fallacies they commit can be a secondary tool for demarcation problem and this tool is consistent with Thagardian approach. In this paper, I selected the astrology as the case and I revealed nine types of logical fallacies (...) frequently committed by astrologers while introducing their field and/or defending their claims against the scientific inquiries and refutation efforts. I also argued that recognizing these fallacies may help the audience to demarcate between the scientific and the pseudoscientific arguments. (shrink)