The situation directly prior to the work of the Cappadocian Fathers was one of extreme confusion due mainly to the lack of agreement on the understanding of various terms. Both orthodox and heterodox authors were using the same terms, but with different meanings, resulting in everyone being suspected of heresy! Confusion centred especially on the meaning of the word hypostasis: should it be used to refer to the 'oneness' or the 'threeness' of God? It was with the intention of resolving this problem that the Council of Alexandria was convened in AD 362, The letter sent by Athanasius and the other bishops present at this Council illustrates exactly the situation that the Cappadocians took up and makes, therefore, a convenient starting point for this survey.
Initially, hypostasis had been synonymous with ousia, and therefore referred to the oneness of God (the three classic examples of this being Hebrews 1:3, the Nicaean Creed anathema, and a letter from Athanasius). But, because of the use of the phrase 'three hypostases' (originated by Origen), there was confusion and counter-accusation: hypostasis could now be used to express either the oneness or the threeness of God.
The Council failed to establish the permitted usage of hypostasis. Despite the acknowledgment by those present that neither of these opposing usages had heretical intentions, they did not clarify what meaning it was now to have. Even the statement that 'all agree together that the faith confessed by the Fathers at Nicaea is better than the said phrases, and that for the future they would prefer to be content to use its language', still left the issue unresolved. Whilst the Nicaean Creed had acknowledged that there was One and Three, it had neglected the formulation of the relationship between them. The implication behind the quotation, however, is that the synonymous usage from the anathema should set the standard: one hypostasis (even though this meant that there was still no accepted word to express the threeness).
The issues concerning which word to use were still far from resolved, despite Gregory of Nazianzen's assertions to the contrary. It was actually Basil of Caesarea who achieved the fixing of terminology and meaning that Gregory ascribed to the Council. Coming from his Origenistic background it was not surprising that Basil should have chosen Origen's formula for the Trinity as his starting point: one ousia, three hypostases. However, it is not enough simply to identify what terms were in use, and how they were enumerated, it is vital that the underlying meanings are also identified.
