In the article, the author expresses his views on the views of the medieval Turkic peoples on the existence and knowledge in the work “Kutadgu bilig” by the great philosopher-scientist Yusuf Khos Hajib. It also analyzed a large-scale encyclopedic guide, a proverb, which reflects the whole existence of habits, moral concepts, moral principles, and norms. It raises many philosophical problems peculiar to the spiritual pursuits of the great medieval thinkers.