Did the first men dream their voyages before making them? Or did they have to first take to the sea so as to be able to later embark on the ship of their imagination and thus embroider on accounts of their journeys? Is it the prestige of the dream that spurred them on to run the risk of translating it into a real experience? Or is it the account of authentic voyages that supported that of imaginary voyages? These are questions that make one dream and that we continue to ask ourselves, even though we suspect that they are idle, since it is impossible to answer them with certitude. All that we know, or think we know, is that among the first written testimonies that have come down to us, real and imaginary voyages are mixed and confused in an alloy of a homogeneity that resists analysis and is perhaps an image of the reception they had from their original public. Who knows if the Greeks who listened in the middle of the first millennium B.C. to the poets singing the return of Ulysses to Ithaca, could, or wanted to, untangle the part of truth from that of poetry? Who knows if the Arabs who, at the end of the following millennium heard the enchanting tale of the voyages of Sinbad, distinguished, as the Western orientalists of the 19th century must have done, the real ports of call and the shipwrecks experienced in the dreamed places and fantastic adventures?