Tyconius' Rules of Chronology: An Innovation

Abstract

In his fifth rule Tyconius shows how the recognition of synecdoche can explain difficulties of Biblical chronology: aut a parte totum aut a toto pars (5 init.).' He chooses for his first illustration the length of the slavery in Egypt. If the Jewish residence in Egypt was 430 years (Exod. 12:40) and Joseph's governorship lasted eighty years (from age 30 to 110: Gen. 41:46 and 50:22), then the period of slavery was 350 years. Why then does the Bible report that the slavery was 400 years (Gen. 15:13)? Synecdoche is the solution: manifestum est centum a toto partem esse, nam post CCC annos pars aliorum centum anni sunt. Propterea dixit CCCC annos (It is plain that the hundred is a whole representing a part; for the years following the first 300 years are part of another hundred, and that is why he spoke of 400 years).2 Similarly, as Tyconius goes on to say, the rule accounts for Scripture's saying ten (months) when it meant nine plus a fraction and three (days) when it meant one whole day plus fractional days before and after.3 Although the recognition of and application of the principle of synecdoche probably goes back to Hellenistic grammarians (it is found clearly and explicitly in Tryphon, a TO OXkov, &ab xoB oi5o6 xo gpoq: Spengel, Rhet. Gr. Vol. 3, 196.1),4 I do not think it was ever used in classical or patristic texts in