A newly deciphered Herculaneum scroll has revealed previously unknown details about the origins of Stoicism and its Greek founder, Zeno of Citium.
The discovery, made possible through a cutting-edge imaging method known as Pulsed Thermography, marks a major advance in efforts to read the carbonized scrolls buried by the eruption of Mount Vesuvius in A.D. 79. The findings were published in Nature by a research team led by Sofia Ceccarelli.
Ancient library preserved by fire and ash
The Herculaneum scroll belongs to a collection of charred manuscripts discovered in the 18th century at the Villa of the Papyri in Herculaneum—believed to have been owned by Lucius Calpurnius Piso, Julius Caesar’s father-in-law. These papyri form the only surviving library from antiquity.
When Vesuvius erupted, intense heat carbonized the scrolls but also preserved them under layers of volcanic material. Their blackened and fragile form has challenged scholars for centuries. Many contain philosophical writings by Philodemus of Gadara, a follower of Epicurus, whose works shed light on the intellectual world of early Roman society.
New imaging breakthrough
Ceccarelli’s team introduced Pulsed Thermography, a non-destructive technique that uses bursts of visible light and an infrared camera to detect hidden text. When light flashes onto the papyrus, inked areas absorb heat differently than the papyrus itself. This contrast allows previously invisible Greek letters to appear on thermal images.
The process raised the temperature of the scrolls by only 2–3°C, a safe level that avoids damage. Researchers emphasized that this minimal heat exposure is far below the 320°C temperature that carbonized the papyri during the eruption.
The study focused on four papyrus fragments containing Philodemus’ “History of the Stoa,” “History of the Academy,” “History of the Garden,” and an anonymous Epicurean ethical treatise. For the first time, the technique allowed scholars to enhance faded passages and verify earlier textual reconstructions.
Rediscovering early Stoic thought
One of the key scrolls, known as PHerc. 1018, contains Philodemus’ “History of the Stoa,” a work chronicling the origins of the Stoic school founded by Zeno of Citium. Using thermographic imaging, the team uncovered clearer readings of lines describing Stoic teachings and historical figures.
The technology confirmed previously disputed passages and helped scholars refine translations of certain words and phrases. In one section, thermal imagery validated a modern interpretation of a phrase meaning “we mentioned earlier,” which had long been debated among experts.
Another scroll, “History of the Academy,” revealed references to Heraclides, a philosopher honored with a crown for his contributions—an episode now more legible than ever before.
Seeing beneath the surface
Beyond revealing text, Pulsed Thermography also exposed the inner structure of the papyri. Thermal maps displayed how sheets of papyrus were glued to backing materials centuries ago, offering insight into ancient restoration and preservation methods.
Regions where the papyrus adhered to the paperboard appeared cooler in thermal images, while detached or layered areas stayed warmer longer. This information, Ceccarelli noted, is vital for conservators working to stabilize the fragile scrolls without unrolling them.
A new era for lost libraries
The Herculaneum papyri have resisted traditional imaging because their carbon-based ink closely resembles the composition of the papyrus itself. Earlier attempts used X-ray tomography, hyperspectral imaging, and near-infrared photography with partial success. Pulsed Thermography now provides a new way to recover both text and structure simultaneously.
Ceccarelli said the method’s success could transform how ancient manuscripts are studied. By revealing ink contrasts and structural layers in a single scan, the approach offers a deeper understanding of the text and the material itself.
Researchers plan to combine thermography with artificial intelligence and pattern recognition in future studies. These tools could automate letter detection and enhance reading accuracy across hundreds of fragments.
The rediscovery of text about Zeno and early Stoicism marks not just a breakthrough in technology but also a revival of ancient thought that once shaped Western philosophy. After nearly 2,000 years in darkness, the words of Greek philosophers are once again visible—this time through the light of science.
