Eduard Zeller is not "one" of the historians of ancient culture. Without any stretch, he can be called the father of the modern European history of philosophy. The work "Greek philosophy in its historical development," which examines the history of ancient philosophy from the era of theo- and cosmological poems to the decline of Neoplatonism in the VI century. n e., first appeared in Tübingen in 1844-52. (3 volumes in 6 books). This is not only an initial attempt to positively and scientifically comprehend the ancient philosophical culture, but also the foundation for all subsequent such attempts. For the first time, it was Zeller who scrupulously studied, compared, interpreted almost all the sources available at that time and approved source study as a necessary prerequisite for historical and philosophical analysis.