The art of beautiful speech has its origins in the ancient Greek tradition. In sophistic discussions of justice and truth, eloquence played a notable role. Plato did not deny the importance of the art of persuasion, but he pointed out the difference between the knowledge provided by philosophy and the belief that is a consequence of persuasion. Therefore, the authors try to shed light on whether rhetoric is a morally neutral skill with a great ability to relativize. In this sense, Kelsen's critique of the natural law concepts of justice and truth are considered. Due to the impossibility of their absolute determination, Kelsen emphasized the fateful significance of theological teachings and rhetoric that convinced people of the existence of ...