Pliny. Illustration of Pliny (AD 23-79), ancient Roman writer and naturalist. His only work to survive is the Natural History, a 37-volume book summarising the knowledge of Pliny's time. It was based on two thousand books by nearly five hundred authors and covered zoology, botany, geography and astronomy. Pliny's book accepted many ideas and descriptions uncritically. Its main message was that everything was centred around humans, being either beneficial, dangerous or teaching a moral lesson. The book was influential and widely copied during the Middle Ages. Pliny was killed by poisonous fumes as he tried to observe the erupt- ion of Mount Vesuvius which destroyed Pompeii.