In a New Light
Since 2002 scientists have been using a technique known as multispectral imaging to take digital photographs of the book's pages at different wavelengths.
The images enable the researchers to pull hidden words out from behind the religious writings.
"There are seven quite large double-sided leaves of new text. We have deciphered around half of this so far," said Robert Sharples, project team member and a classicist at University College London.
After the Archimedes and Hyperides works were found, the team fine-tuned their multispectral imaging technique.
Revisiting some of the more difficult pages in the book revealed the writings on Aristotle.
"Even though I couldn't read ancient Greek, just the fact that I could see the words gave me shivers," Easton told BBC News.
Experts on ancient Greek texts are currently scouring the newfound work.
Clues, such as a name in the margin, indicate that the writings are an early commentary on Aristotle's Categories, one of the foundations of Western studies of logic.
"If this is the case, then it is an immensely significant find and very exciting," said David Evans, professor of logic and metaphysics at Queens University Belfast in Ireland.
The most likely author of the new find is thought to be Alexander of Aphrodisias.
"He was a philiosopher in his own right and a very important and insightful commentator," Evans said.
Translation of the text so far suggests that it may provide further insight into a debate on Aristotle's theory of classification.
"We have one book that contains three texts from the ancient world that are absolutely central to our understanding of mathematics, politics, and now philosophy," Noel, of the Walters Art Museum, told BBC News.
"I am at a loss for words at what this book has turned out to be. To make these discoveries in the 21st century is frankly nutty—it is just so exciting."
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