ABSTRACT
It is told (by Cicero, one of the greatest Roman orators and statesmen) that Hippocrates (a renowned physician of ancient Greece) suspected a pair of brothers to be twins1. Hippocrates reached this conclusion because they both became ill at the same time, and their disease progressed to a crisis and subsided in the same length of time for each of them. The astrologer Posidonius the Stoic chal-lenged this diagnosis of twinning, and explained this coincidence by the fact that the two brothers were conceived and born under the same constella-tion (Figure 13.1).
