A term occasionally used in connection with the fourth-century Arian* controversy. The orthodox party, led by Athanasius,* defined the Son as homoousios-the same identical essence or substance as the Father. Arian groups taught that He was homoiousios (like essence) or homois (like) or anomoios (unlike). The Greek ousia (essence) had an imprecise Latin equivalent in substantia, and consubstantialis therefore became the equivalent of the orthodox homoousios.