An Attempt to Contain the World

The Natural History is thirty seven books, and Pliny says in the preface that it holds twenty thousand facts worth knowing, drawn from two thousand volumes by a hundred authors. He supplied an index book listing his sources for each of the others, which makes the work a bibliography of a library that has otherwise perished, and much of what is known about lost Greek and Roman writing on medicine, minerals and botany is known because he cited it.

The theology in it is Stoic and stated openly in the second book: the world itself is what should be understood as divine, eternal, boundless and without beginning, and the crowd of gods with human passions and marriages is a symptom of human weakness. That does not stop him recording every rite and remedy he can find. His book on the origins of magic is hostile, deriving the art from Persia and treating it as fraud, and is also the fullest surviving Roman account of what magi were believed to do. His description of druids cutting mistletoe from an oak with a golden sickle, catching it in a white cloak and sacrificing two white bulls, is a few sentences long and is the foundation of nearly everything later Europe thought it knew about them.