Herodotus

Herodotus does something no earlier Greek writer had done systematically: he sets the religion of other peoples beside his own and treats them as versions of one another. Egyptian deities are named with Greek names throughout, Amun appears as Zeus and Osiris as Dionysus, and he argues that the Greeks took the names of most of their gods from Egypt. That habit, later called interpretatio graeca, decided how the ancient Mediterranean would think about foreign gods for centuries, and it is a method with a cost, since it makes every unfamiliar deity a familiar one in disguise.

The method he uses on evidence is worth as much. He reports what he was told, names who told him, and frequently offers two or three incompatible explanations without choosing between them; when he does not believe something he says so and reports it anyway. He tells how Croesus tested the oracles by asking each what he was doing on an appointed day, and how only Delphi answered correctly, which is a story about verification told inside a religious frame. Running under all of it is a theology of a kind: greatness attracts divine resentment, the god does not permit anyone but himself to think high thoughts, and the warning that no life should be called fortunate before it is over.

For a great deal of ancient religion Herodotus is not the best witness but the only one. Persian practice without images, temples or altars, with sacrifice on a high place and a magus chanting a theogony over the victim, comes from him. So does Scythian burial, the killing of horses and attendants, the mound raised over the king, and the vapour bath in which hemp seed is thrown on hot stones inside a felt tent while the mourners howl with pleasure. So do whole layers of Egyptian practice, the grades of mummification and their prices, the animal cults, the festival crowds on the Nile, the prohibitions and purities of the priests.

Some of it has been confirmed since. Excavated Scythian burial mounds have produced the horse sacrifices, the tent frames and the hemp, in an arrangement close enough to his description to be striking. Other parts have not been confirmed and probably cannot be. He has been called the father of history and the father of lies since antiquity, and the honest position is that he is a reporter of what people said about themselves, which is a different and often more useful thing than a record of what they did. Reading him requires keeping both facts in mind at once, and the atlas cites him on that understanding.