And in order that what we say may be more easily understood, let us take an illustration from things very dissimilar. There are many persons who take a part in the science or art of medicine: are we therefore to suppose that those who do so take to themselves the particles of some body called medicine, which is placed before them, and in this way participate in the same? Or must we not rather understand that all who with quick and trained minds come to understand the art and discipline itself, may be said to be partakers of the art of healing? But these are not to be deemed altogether parallel instances in a comparison of medicine to the Holy Spirit, as they have been adduced only to establish that that is not necessarily to be considered a body, a share in which is possessed by many individuals. For the Holy Spirit differs widely from the method or science of medicine, in respect that the Holy Spirit is an intellectual existence and subsists and exists in a peculiar manner, whereas medicine is not at all of that nature. (Book I, Section 3)

As Origen was writing in Greek and insisting on a non-corporeal, entirely spiritual nature of God, Tertullian was writing in Latin and insisting on the opposite.

Where Origen is clearly incorporating platonic and neo-platonic ideas into his work, Tertullian despised Greek philosophical speculation and embraced a very material reality.

Yet both were men of deep faith and each had considerable influence on the orthodoxy that emerged in the generations after them. What intrigues me is the freedom and multiple possibilities that existed at this moment, late in the second century, when these issues were very present but far from resolved.

What we are reading in Origen is one of the earliest efforts at systematic theology.