An Israeli algorithm sheds light on the Bible

The program recognizes repeated word selections, like uses of the Hebrew equivalents of "if," ''and" and "but," and notices synonyms: In some places, for example, the Bible gives the word for "staff" as "makel," while in others it uses "mateh" for the same object. The program then separates the text into strands it believes to be the work of different people.

Other researchers have looked at linguistic fingerprints in less sacred texts as a way of identifying unknown writers. In the 1990s, the Vassar English professor Donald Foster famously identified the journalist Joe Klein as the anonymous author of the book "Primary Colors" by looking at minor details like punctuation.

In 2003, Koppel was part of a research team that developed software that could successfully tell, four times out of five, if the author of a text was male or female. Women, the researchers found, are far more likely to use personal pronouns like "she" and "he," while men prefer determiners like "that" and "this" — women, in other words, talk about people, while men prefer to talk about things. That success sparked debate about how gender shapes the way we think and communicate.

Research of this kind has potential applications for law enforcement, allowing authorities to catch imposters or to match anonymous texts with possible authors by identifying linguistic tics. Because the analysis can also help identify gender and age, it might also allow advertisers to better target customers.

The new software might be used to investigate Shakespeare's plays and settle lingering questions of authorship or co-authorship, mused Graeme Hirst, a professor of computational linguistics at the University of Toronto. Or it could be applied to modern texts: "It would be interesting to see if in more cases we can tease apart who wrote what," Hirst said.

The algorithm might also lead to the creation of a style checker for documents prepared by multiple authors or committees, helping iron out awkward style variations and creating a uniform text, Hirst suggested.

What the algorithm won't answer, say the researchers who created it, is the question of whether the Bible is human or divine. Three of the four scholars, including Koppel, are religious Jews who subscribe in some form to the belief that the Torah was dictated to Moses in its entirety by a single author: God.

For academic scholars, the existence of different stylistic threads in the Bible indicates human authorship.

But the research team says in their paper they aren't addressing "how or why such distinct threads exist."

"Those for whom it is a matter of faith that the Pentateuch is not a composition of multiple writers can view the distinction investigated here as that of multiple styles," they said.

In other words, there's no reason why God could not write a book in different voices.

"No amount of research is going to resolve that issue," said Koppel.