Barth has been an influential scholar on the subject of ethnicity. Andreas Wimmer wrote in 2008, "The comparative study of ethnicity rests firmly on the ground established by Fredrik Barth in his well-known introduction to a collection of ethnographic case studies." As the editor of "Ethnic Groups and Boundaries" (1969), Barth outlined an approach to the study of ethnicity that focused on the ongoing negotiations of boundaries between groups of people. Barth's view was that such groups were not discontinuous cultural isolates, or logical "a prioris" to which people naturally belong.