Polemics refers to the practice of challenging and refuting
doctrinal errors or providing correctives within the same belief system (or religion). This may be contrasted with apologetics which attempts to defend one's beliefs to outsiders. Polemics, therefore,
may be viewed as dialogue internal to Christianity, and apologetics as dialogue to defend Christianity to non-Christians.
early church fathers are sometimes categorized as either polemicists or apologists based on the thrust of their writings.
The following are examples of practice polemics: