ENThe paper is about rationalism and rationality in the context of science and myth. Revealing a similarity as well as different ontological foundations and premises of ancient Hellenic and modern science, the author speaks about the need for different scientific discourses and even different sciences, including scientia sacra in the sense explored by S. H. Nasr. There are different types of rationality; therefore, the modern Western rationality (which appeared in the 17th and 18th centuries and is connected with the philosophy of Descartes) cannot be regarded as a sort of universal and purely objective perspective. This modem rationality must be viewed as a kind of ideology, historically determined by various religious and cultural changes that took place within Western civilization after the Renaissance. Therefore, the foundation of modern materialistic science (one-sided and reductionist as it is) is "mythological" as well. It is necessary to understand different ways of thinking and realize that some ancient views about the cosmos are still valid if they are regarded according to certain metaphysical principles and interpreted symbolically as the vehicles of traditionally shaped spiritual truths.