It’s my birthday today. The LRB has sent me a copy of The Birthday Book, which the Roman scholar Censorinus wrote for his friend Caerellius in 238 AD, and which has recently been translated into English for the first time by Holt Parker, who dedicates his translation ‘to Barbara, for her birthday’ (Chicago, £12). ‘Because you have no lack of precious gifts because of the virtue of your soul,’ Censorinus writes, ‘and I have no excess because of the thinness of my income, I have sent you this book (take it for what it’s worth) composed from my riches, and put the title “Birthday Present” on it.’ It’s hard not to see this as the Stoic equivalent of ‘Sorry I haven’t got you anything, but hey! I made you a card’ – though maybe that’s ungenerous of me.
In The Birthday Book, Censorinus distils the wisdom of several strains of philosophy, extracting whatever seems to have any bearing on births, days and birthdays: theories of the origin of the human species, the formation of the individual foetus, the principles of astrology, the ages of man, the nature of time, eons, centuries, years, months, days and hours. He tends not to align himself definitively with one view or another, though he expresses healthy doubts about some of the more ‘fabulous stories of the poets’ – that Prometheus moulded the first people out of clay, for example – and the ‘no less incredible’ theories of some philosophers, such as Empedocles’ idea that ‘in the beginning individual members were produced everywhere out of the earth, as if it were pregnant, then they came together and produced the material for a complete human being, composed of fire and moisture mixed. But what is the point of continuing with these improbable things?’
He isn’t so sceptical about the teachings of the Pythagoreans, however. And when it comes to in utero development, Censorinus puzzles over all kinds of outlandish suggestion: that the sex of the foetus is determined by the relative heat of the mother’s and father’s seed, or by the thickness of the seed, or by whether the seed comes from the right or left side of the body. And as for the gestation period, that’s considered to be an exact number of months: usually seven or nine, sometimes ten, but according to most authorities never eight – for profound astrological reasons. Of course it’s easy enough to pour scorn on such ideas with several centuries of hindsight; all the same, it’s hard to avoid the thought that the ancient philosophers would have been able to discard at least some of their wilder hypotheses if only they’d taken the trouble to canvas the views of one or two women.
Censorinus is meticulous in acknowledging the sources that he has consulted, however, and Parker’s useful notes expand on Censorinus’ references and fill in the gaps, even if his grasp of mathematical terms is sometimes a little shaky: ‘The Greeks had an aesthetic preference for fractions with a denominator of 1,’ he writes. He means to say that they preferred fractions such as one-half, one-third, one-quarter and so on, in which case the word he’s looking for is ‘numerator’; fractions with a denominator of 1 are more commonly known as ‘whole numbers’.
Though this is its first translation into English, The Birthday Book enjoyed many centuries of popularity. ‘It has come down to us through a large number of manuscripts from as early as the beginning of the eighth century ad,’ Parker says, and ‘was among the earliest books printed in Europe, with a first edition in 1497, and new editions in 1498 and 1500, with eight more in the 16th century alone’. Copernicus and Kepler were both familiar with it. And even if the book itself has since fallen into obscurity, its form is recognisable in such modern assemblages as Schott’s Miscellany or Does Anything Eat Wasps?, or the diary I had as a child, full of useful and unsubstantiated facts, including the information that I shared a birthday with Charles Dickens, the Appalachian banjo-player Dock Boggs, and Julius Caesar.
All other authorities seem to agree, however – and it’s only just occurred to me to check this – that Julius Caesar was born in the middle of July. Unhelpfully, few of them say which calendar they’re using, and for a while – about half an hour – I clung to the hope that the 13th day of the month of Quintilis in the year 653 auc (ab urbe condita, ‘after the founding of Rome’) was exactly 2108 solar years ago: i.e., if the Gregorian calendar were extrapolated back to 100 BC, Caesar and I would still share a birthday. (Why should I care? Good question. Something to do with the difficulty of letting go of childhood illusions, probably. Or maybe it’s because I’m an Aquarius.) It was Julius Caesar who first sorted out the Western calendar into a more or less sensible system. Before he and Sosigenes of Alexandria, an astronomer, fixed the year at 365.25 days and realigned the months with the seasons (by adding 67 extra days to 46 BC, on top of the 23 days that had to be added anyway – don’t ask why), it was all a bit of a shambles, as Censorinus makes delightfully clear. Be that as it may, the sad fact remains that however I try to fiddle it, I don’t share a birthday with Caesar. Time to give up those plans of conquering Gaul.