Lecture 5.3  Optics and Astrology

Lindberg  ch. 2
GS ch 4  pp 82ff

I. Optics

geometric study of light
    from Aristotle’s time (384-322)
        simple appearances; reflection (dioptrics), refraction
    Euclid wrote first major treatise
    Diocles (dioptrics) active c. 185 BC
    Ptolemy study indices of refraction

Nature of Vision
    eidola (atomists);
    potentially transparent (Aristotle);
    visual ray: only one optic ray from the eye

Euclid
proving what is obvious: importance of mathematical understanding
closer objects are seen better, parallel objects seem to bend in
apparent inconsistency: we take account of distance so as to perceive a concave surface, but not so as to get a different sense of height.

II. Astrology

Babylonian astrology
Egyptian decans
Nechepso and Petosiris

Hellenistic Astrology
horoscope: ascendent; heliacal rising
Places (modern mundane houses): life, money, brothers, parents etc.
aspects, conjunction, square, trine, sextile
Houses: e.g. Sat: Aqu and Capr
exaltation and depression

Iatromathematical treatises
    if you fall ill today, Feb 4, 2005
    moon 25 Sag (losing light; increasing in numbers); Mars 27 Sag; Jup 18 Lib; Ven 0 Aqu; Merc. 6 Aqu; Sat 22 Can;
    you’re probably OK; but if there had been increase in light and numbers, the beginning of disease would be from parties and drinking bouts; continuous and strained fevers, fluxions, choleric suffering and flowing of the bowels and weak pulse; cooling and costive things are a help; if a malefic aspects, you’ll die on the 7th day.  If a benefic aspects you will save after the opposition

Astronomers who were astrologers: Hipparchus and Ptolemy
Stoics and Cicero: twins argument: have different lives but same horoscope
Christian reaction: the visit of the Magi and the star of Bethlehem