Dardel assertion that myths are neither true nor false can be explained the following way. Many mythologies are composed in the form of epic poems. And poetry hands its writer with an artistic license, and allows him to concentrate on the aesthetic aspects of the work. Inevitably, factuality becomes irrelevant in such a scenario. Hence, the distinction between the literal and metaphorical representations becomes impossible to ascertain. Also, the usual mode of propagation is through oratorical recitals. In such a transfer of information, a certain degree of mutation is inevitable and in most such cases indiscernible.
Dardel also states that the myth is always in the present and never in the past. This could be understood by considering the fact that all myths were a product of the respective elites. And as an instrument of preserving the elite interests, the significance of all mythology is to manufacture the desired social order at any given time present. So, although they are by definition historical relics of art and literature, their action on the collective consciousness of any society is a continuous process that cannot be confined to just a particular time period. Hence, the myth is always in the present and never in the past.
Rank, Otto. (2004). The myth of the birth of the hero: A psychological interpretation of mythology (Gregory C. Richter and E. James Lieberman, Trans.) Baltimore, M.: Johns Hopkins University Press. (Originally work published 1909)
Tylor, E.B., Primitive Culture: researches into the development of mythology, philosophy, religion and art., 1871, Routledge/Thoemmes.
Hard, Robin., The Routledge Handbook of Greek Mythology (based on H.J.Rose’s original work), Routledge, 2003.