4. Kroll, _Aus der Gesch. der Astrol._ (_Neue Jahrb. für das klass.
Altertum_, VII), 1901, pp. 598 ff. Cf. Boll, _Cat. codd. astr._, VII, p.
130.
5. The argumentation of Posidonius, placed at the beginning of the
Tetrabiblos, inspired the defense of astrology, and it has been drawn upon
considerably by authors of widely different spirit and tendencies, see
Boll, _Studien über Claudius Ptolemäus_, 1894, pp. 133 ff.