Marcianus Aristides was Greek philosopher of the 2nd century A.D., who was considered to be the first Christian apologist. His name is also spelled Aristeides. He was known as Aristides of Athens. Nothing is known about his life except that he taught philosophy at Athens and composed the earliest extant defense of Christianity, the Apology of Aristides. Written in Greek, the Apology may have been written to Emperor Antoninus Pius about 139.
The Apology was long considered lost, but in 1878 an edition of an Armenian fragment appeared at Venice. This was followed in 1889 by James Rendel Harris' discovery of a complete Syriac version in a monastery on Mount Sinai. Publication of this translation at Cambridge, England, in 1891 led to the discovery that a Greek text of the treatise had existed for centuries in the religious romance Barlaam and Josaphat. Two portions of the Greek text were published in London in 1922 and 1924.
The Apology is brief, simple, and objective, but written in a lofty tone. It discusses the errors of Greeks, Chaldeans, Egyptians, and Jews concerning God, gives a summary of a seemingly primitive Christian belief, and emphasizes the righteousness of Christianity in contrast with the corrupt practices of paganism. Aristides seeks to demonstrate the reasonableness of Christianity by an appeal to facts.