Not the same as Aristides, Aelius, a sophist, also active 2nd century.
His The apology of Aristides on behalf of the Christians, 1893.
New Cath. encyc. (Aristides, 2nd cent.; Athenian philosopher and Christian apologist; author of Apology for the Christian faith; no mention of sainthood for Aristides)
Encic. catt. (Aristide, Marciano; one of the first Christian apologists, Athenian philosopher who presented an Apologia to Emperor Hadrian)
Encyc. Brit., 15th ed. (Aristides, fl. 2nd cent.; Athenian philosopher, one of the earliest Christian apologists; his Apology for the Christian faith one of the oldest extant apologist documents; no mention of sainthood for Aristides)
NUC pre-1956 (Aristides, Marcianus, Saint, of Athens)
Holweck's Biog. dict. of the saints, 1924 (Aristides, philosopher and Christian apologist; native of Athens, converted to the faith, wrote an apologetic treatise; feast day Aug. 31 in Roman martyrology, Sept. 13 in Athens)
His Apologia, 1988 t.p. (Aristide di Atene)
Quasten, J. Patrology, 1983 v. 1, p. 191 (Aristides of Athens)