VETTIUS VALENS AND THE PLANETARY WEEK ROBERT L. ODOM Washington, D.C. A very important testimony concerning the planetary week in the second century A.D. is that of Vettius Valens, a noted astrologer of Antioch, who was active during the reigns of Antoninus Pius (138-161) and Marcus Aurelius (161-180). His Anthology, an astrological treatise written in Greek, has been a valuable subject of study by scholars because of the astro- nomical and chronological data it contains. 0 t to Neugebauer, noted expert in the mathematics of ancient astronomy, has worked out, with the collaboration of Henry B. Van Hoesen, the horoscopes recorded by that astrologer. In their book presenting their findings they say : The importance of the Anthology of Vettius Valens for our subject can be illustrated by the following figures. With its about r30 (partial or complete) horoscopes it contains twice as many examples of Greek horoscopes as all papyri combined. Without Vettius Valens (whose examples range from A.D. 37-188) we should have only five examples of 'literary' horoscopes before A.D. 380. The same scholars report: The fact that every one of these horoscopes can be shown to be astronomically correct for a date in the first or second century A.D. is therefore proof that Vettius Valens was using empirical material exclusively, collected either by himself or by his prede- cessors. 1 Franz Cumont, "The Frontier Provinces of the East," The Cam- bridge Ancienb History, XI (New York, 1936), 643 ; Astrology and Religion among the Greeks and Romans (New York, 191 2), pp. 36, 86, 87, 93; The Oriental Religions in Roman Paganism (New York, 1956)' p. 171 ; F. H. Colson, The Week (Cambridge, Engl., 1926). pp. 47-52. 2 Otto Neugebauer and Henry B. Van Hoesen, Geek Horoscofles (Philadelphia, 1959), p. I 76. I gratefully acknowIedge the kindness of Dr. Neugebauer for reading this paper and making helpful suggestions, although the conclusions reached are my own. Ibid.