NPNF2-08. Basil: Letters and Select Works - Holy Bible Institute

To Eustathius the physician.any one give an account of each one of these names, and of the actual nature to which theyare applied, and it will be found that the definition will not in both cases be the same. Andwhere the definition is not identical the nature is different. There is, then, a distinction tobe observed between the essence, of which no explanatory term has yet been discovered,and the meaning of the names applied to it in reference to some operation or dignity. Thatthere should be no difference in the operations we infer from the community of terms. But,we derive no clear proof of variation in nature, because, as has been said, identity of operationsindicates community of nature. If then Godhead be the name of an operation, we saythat the Godhead is one, as there is one operation of Father, Son, and Holy Ghost; if, however,as is popularly supposed, the name of Godhead indicates nature, then, since we find novariation in the nature, we reasonably define the Holy Trinity to be of one Godhead.232665