Mr. C.F.H. Johnston quotes as instances of the application of the word “third” to the Holy Ghost; Justin Martyr (Apol. i. 13) “We honour the Spirit of prophecy in the third rank.”  Tertullian (In Prax. 8) “As the fruit from the tree is third from the root, and the rivulet from the river third from the source, and the flame from the ray third from the sun.”  Eunomius (Lib. Apol. § 25) “observing the teaching of Saints, we have learned from them that the Holy Spirit is third in dignity and order, and so have believed him to be third in nature also.”  On the last St. Basil (Adv. Eunom. ii.) rejoins “Perhaps the word of piety allows Him to come in rank second to the Son…although He is inferior to the Son in rank and dignity (that we may make the utmost possible concession) it does not reasonably follow thence that he is of a different nature.”  On the word “perhaps” a dispute arose at the Council of Florence, the Latins denying its genuineness.