Tertullian has the true formula for the Holy Trinity, tres Personae, una Substantia. The Father, Son, and Holy Ghost are numerically distinct, and each is God; they are of one substance, one state, and one power. So far the doctrine is accurately Nicene. But by the side of this appears the Greek view which was one day to develop into Arianism: that the unity is to be sought not in the Essence but in the origin of the Persons. He says that from all eternity there was reason (ratio) in God, and in reason the Word (Sermo), not distinct from God, but in vulva cordis. For the purpose of creation the Word received a perfect birth as Son. There was a time when there was no Son and no sin, when God was neither Father nor Judge.
Do you think this assessment is accurate? Where in his writings does it become clear? Are there any other aspects of Tertullian's trinitarianism that wouldn't accord with Nicea?