Reading the church fathers on numerology is one of those instances at which you find yourself thinking that (historically speaking) “we’re not in Kansas anymore, Toto.”
When you see the multiple significances that Augustine’s Pentecost Sermo 270 derives from the number 10, Sesame Street’s Count von Count begins to look less obsessive.
This all a round-about way of saying that during tea-break yesterday morning, I got some way towards working out the meaning of something that had been puzzling me while looking at mosaics on a trip to Ravenna last month: what were those letters doing on the sleeves of clerical tunics?
Look at the picture above, and you’ll notice that Saint Lawrence has the letter I on his sleeve-tips. I’ll post some more images later in the week just to show that these marks are actually letters and not stripes of some kind. You’ll also see Z, H and Γ (the last of which makes it clear they’re Greek rather than Latin letters).
What I discovered is that they’re the Greek numbers – γ=3 ζ=7 η=8 ι=10 – and each of the numbers is invested with an ocean of theological meaning.
The technical name for these markers is gammadia (singular gammadion – from gamma).
In the image above (from the 5th century mausoleum of Galla Placidia in Ravenna) St. Lawrence is marked with the number 10 (iota) which signifies the ten commandments or the law, and the four gospels (since 1+2+3+4=10). My guess is that this choice of number is connected with the open Gospel carried by the deacon Lawrence on his way to the grill.
There’s a series of papers on each of the gammadia, to which I don’t have access, alas. They’re by A. Quacquarelli and in the Italian journal Vetera Christianorum. Feed “gammadia” into Scholar Google and you’ll turn them up. Alas, no New Zealand library holds the series.
However, you should also find what seems to be a resumé of Quacquarelli’s findings in a downloadable article by Maria Paola Biaggio “Simboli cristologici e iconografia.” I flogged most of the above information from this. She can tell you about the significance of the other gammadia as well.
BTW, I fed “gammadia” and “gammadion” into commercial databases such as ATLA and didn’t turn up much of any use. Full marks, again, to scholar google!