Adrastus of Cyzicus is an individual who is mentioned along with Dion of Naples in a work of Augustine of Hippo

Augustine of Hippo

Augustine of Hippo , also known as Augustine, St. Augustine, St. Austin, St. Augoustinos, Blessed Augustine, or St. Augustine the Blessed, was Bishop of Hippo Regius . He was a Latin-speaking philosopher and theologian who lived in the Roman Africa Province...

. He was apparently an ancient Roman

Ancient Rome

Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

  astronomer

Astronomer

An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

. Although, from Augustine's brief and second-hand account, we can know very little of his life or works, he was cited as an authoritative astronomical observer from antiquity.

According to Augustine's De Civitate Dei contra Paganos, Varro

Marcus Terentius Varro

Marcus Terentius Varro was an ancient Roman scholar and writer. He is sometimes called Varro Reatinus to distinguish him from his younger contemporary Varro Atacinus.-Biography:...

 (116 BC – 27 BC) the Roman

Ancient Rome

Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

 scholar and writer, cited Adrastus and Dion as authorities for the dating of an astronomical phenomena involving Venus

Venus

Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...

, describing them as mathematici nobiles (distinuguished astronomers, or possibly astrologers). Again according to Augustine, Varro recorded this in his work De gente populi Romani. Although Varro's writing is now lost, Augustine quoted from it:
Augustine used these ancient astronomical reports to further his what has been called his "epistemic theory of miracles

Epistemic theory of miracles

The epistemic theory of miracles is the name given by the philosopher William Vallicella to the theory of miraculous events given by St. Augustine and Baruch Spinoza. According to the theory, there are no events contrary to nature — that is no "transgressions", in Hume's sense, of the laws of nature...

". Here, Augustine argued that if Varro called the phenomenon that Adrastus and Deon reported, a "portent", then it could not be contrary to nature, but must simply be inexplicable under our current understanding of nature.

In antiquity, Cyzicus

Cyzicus

Cyzicus was an ancient town of Mysia in Anatolia in the current Balıkesir Province of Turkey. It was located on the shoreward side of the present Kapıdağ Peninsula , a tombolo which is said to have originally been an island in the Sea of Marmara only to be connected to the mainland in historic...

 was an important commercial town in Mysia

Mysia

Mysia was a region in the northwest of ancient Asia Minor or Anatolia . It was located on the south coast of the Sea of Marmara. It was bounded by Bithynia on the east, Phrygia on the southeast, Lydia on the south, Aeolis on the southwest, Troad on the west and by the Propontis on the north...

 in Anatolia

Anatolia

Anatolia is a geographic and historical term denoting the westernmost protrusion of Asia, comprising the majority of the Republic of Turkey...

.