"For Stevin, the "signs" that in earlier times a "golden age" (aurea aetas) of science actually existed are these: 1. The traces of a perfected astronomical knowledge found in Hipparchus and Ptolemy, whose writings he understands as mere "vestiges" of primeval knowledge... 2. Algebra, as we have become acquainted with it through Arabic books and which represents one of the strangest "vestiges" of the "wise age." No trace of it is found in the Chaldeans, the Hebrews, the Romans, and even the Greeks... 3. Evidence of the foreign origin Greek geometry. ... 4. Information concerning the height of the clouds, which appears in an Arabic work and which Stevin does not hesitate to trace back to the science of the "wise age." "Alchemy," which was unknown to the Greeks and whose most expert representative Stevin saw as Hermes Trismegistos."