Of the One Substance
1 The plant that springs from the root is something distinct from that whence it grows up; and yet it is of one nature with it. And the river which flows from the fountain is something distinct from the fountain. For we cannot call either the river a fountain, or the fountain a river. Nevertheless we allow that they are both one according to nature, and also one in substance; and we admit that the fountain may be conceived of as father, and that the river is what is begotten of the fountain.21 That the Son is not different from the Father in nature, but connatural and consubstantial with Him. From the Panoplia of Euthymius Zigabenus in the Cod. xix. Nanianae Biblioth.
2 [See his explanations in the epistle to Dionysius p. 92, supra ]