Now the fact that there is no distinction in the operations we learn from the community of the attributes, but of the difference in respect of nature we find no clear proof, the identity of operations indicating rather, as we said, community of nature. If, then, Godhead is a name derived from operation, as we say that the operation of the Father, and the Son, and the Holy Spirit is one, so we say that the Godhead is one: or if, according to the view of the majority, Godhead is indicative of nature, since we cannot find any diversity in their nature, we not unreasonably define the Holy Trinity to be of one Godhead .
St Gregory of Nyssa
On the Holy Trinity
