The Institutes of Gaius: in English and Latin - Paperbackby Gaius (Author) "The value attached to Gaius's powers of theoretical exposition, and to the admirable clearness and method which made his Institutions the basis of all future teaching in Roman law, must have been great" A. H. J. Greenidge, Introduction, The Institutes of Gaius (1904) The Institutes of Gaius (1904) written by Gaius in AD 161, is considered an authoritative text on private Roman law beginning in the second century and for the three