When the definitions of folklore to date in Germany (for example, Kant) are taken into a general consideration in the discussions concerning the scientific basis of folklore, regarding the last quarter of the 18th century especially the ideas of Johann Gottfried Herder (1744-1803) as expressed in his "Abhandlung fiber den Ursprung der Spache" and his "Fragmente zur deutschen Literatur" are to be taken into serious account. It must be remembered that in the folklore discussions, the problematic concept of a 'folk' is widely referred to. Herder defines the concept of a 'folk' according to his peculiar folklore concept. Meral Ozan studies the different meanings in which Herder uses the 'folk' concept, and comes to the following results (Milli Folklor Dergisi Say1 45): It can mean 1) smaller or bigger group of people, 2) a people that forms a state, 3) the lower classes of a society, and 4) a nation. Notwithstanding, this study aims to give a more detailed account of Herder's thoughts regarding the concepts of 'folk' and 'folklore' in order to enable the readers to have a better understanding of Herder's specific use of these concepts. Also it must not be forgotten that Herder's thoughts on the concepts of 'folk' and 'folklore' bear the mark of his time. Therefore, we suggest looking at Herder's approach within the context of (especially) Kant and the philosophy of the Enlightenment. We want to expose how Herder used these concepts within his own historical problematic and within his own philosophical system, to focus on the theoretical problems that Herder tried to solve within the context of his national and cultural context, and especially to emphasise that Herder was bringing the concept of 'folk' into the fore in order to attack other theories. By examining the concept of 'folk' we also intent to expose how Herder's understanding of polyculture and cultural relativism had developed. Thus, we wish to show that Herder not only conceptualized his theory of cultural relativism, but that he also determined a clear field of research on folklore. In this regard, Herder's article on the origin of language does not only deal with the question of how language came into being; eventually, his language theory is based on the concepts of 'folk' and 'folk spirit'. Herder defends the thesis that only by means of the inherent creative power of language a national consciousness can be developed by people. In this study, Herder's concept of 'folk' will be examined also under this point of view. This will lead us to maybe the most important contribution of Herder to folklore as a field of research. In Herder's opinion race or ethnic identity are the concrete formations of the folk spirit as a form of consciousness. Herder believes that this spirit (this social consciousness) cannot come into existence without language. In his view every 'folk' has to create his own specific forms of expression (discourses), and among these media language is the most important one. By means of this thesis, Herder tries to establish logical relations between a national folklore (the folklore of a nation) and history, and he does not hesitate to apply these concepts to research in folklore and 'folk'.