Cultural relativists challenge the idea of universal human rights by arguing that each culture is unique and has its own authoritative morality that cannot be compared to others. They believe that cultural practices and norms exist within cultures prior to the establishment of universal human rights. However, others argue that through cross-cultural exchange of ideas, certain rights like the presumption of innocence have been recognized across cultures and civilizations throughout history. While implementing universal human rights can be difficult due to cultural and identity differences, some think a harmonious understanding is possible through respectful dialogue among civilizations.