The history of doctrinal development could be described as a record of discarded solutions. Typically, a promising theory is advanced, explored, found wanting and left behind, with a legacy of terminological clarification and complexification to make the next round of discussion still more difficult. The definitions of the fourth and fifth centuries are not very stable compounds of these terminological experiments: a precariously balanced set of warnings and prescriptions, within whose boundaries we may expect to encounter the truth. To criticise them as unnecessarily elaborate philosophical theses is to miss their character entirely. The processes of debate give the terms their meaning, not some imagined philosophical hinterland; and they seek not to exhaust but to mark out where the risks and incoherences lie in talk about God’s revelations.
Frequently, as is often remarked, they react against a too tightly worked theory which leaves out of account some fundamental concern. Thus the popularity in the first and second Christian centuries of theologies that played down the humanity of Jesus left out the significance of the human locus of his divine activity. If sacred power is not alive and sustaining itself in the midst of actual human suffering, something essential is lost. And if Jesus is the earthly form of some great angelic power – manifestly a popular structure within which to interpret him in the first Christian generations – this fits neatly (though in slightly different ways) into the cosmology of both Greek and Jewish belief, but leaves open the question of whether it is God’s power we are dealing with.
Rabbinic controversies over the existence of a ‘second power’ in heaven reveal that these issues were not unique to Christians. Yet a theology that treated Jesus as a great human saint promoted to quasi-divine status for his achievement is – curiously to modern eyes – hardly in evidence at all. Even where the language of ‘promotion’ or exaltation is used (as in Acts or Hebrews in the New Testament), it is made clear that direct divine power is from the first at work in him and that the divine initiative is prior to any kind of reward for human virtue. When the most careful and sophisticated theory of all to date is advanced at the beginning of the fourth century by the Alexandrian priest Arius – a theory scrupulously grounded in liturgical language as well as terminological analysis – it provokes the most violent reactions to date.
From chapter 2 of Why Study the Past? – the quest for the historical church, published by Darton Longman and Todd 2005