Like a snake eating itself, in both directions ....
This is what Gibbons says about the development of Trinitarian theology, and it's derivation of Platonic philosophy ..
From "The Decline And Fall Of The Roman Empire"m Ch. 21 :
http://www.ccel.org/g/gibbon/decline/volume1/cntnt21.htmThe Trinitarian controversy.
The schism of the Donatists was confined to Africa; the more diffusive mischief of the Trinitarian controversy successively penetrated into every part of the Christian world. The former was an accidental quarrel, occasioned by the abuse of freedom; the latter was a high and mysterious argument, derived from the abuse of philosophy. From the age of Constantine to that of Clovis and Theodoric, the temporal interests both of the Romans and barbarians were deeply involved in the theological disputes of Arianism. The historian may therefore be permitted respectfully to withdraw the veil of the sanctuary, and to deduce the progress of reason and faith, of error and passion, from the school of Plato to the decline and fall of the empire.
The system of Plato. Before Christ 360.
The genius of Plato, informed by his own meditation or by the traditional knowledge of :he priests of Egypt,(11) had ventured to explore the mysterious nature of the Deity. When he had elevated his mind to the sublime contemplation of the first self-existent, necessary cause of the universe, the Athenian sage was incapable of conceiving how the simple unity of his essence could admit the infinite variety of distinct and successive ideas which compose the model of the intellectual world; how a Being purely incorporeal could execute that perfect model, and mould with a plastic hand the rude and independent chaos. The vain hope of extricating himself from these difficulties, which must ever oppress the feeble powers of the human mind, might induce Plato to consider the divine nature under the threefold modification - of the first cause, the reason, or The LogosLogos, and the soul or spirit of the universe. His poetical imagination sometimes fixed and animated these metaphysical abstractions; the three archical or original principles were represented in the Platonic system as three Gods, united with each other by a mysterious and ineffable generation; and the Logos was particularly considered under the more accessible character of the Son of an Eternal Father, and the Creator and Governor of he world. Such appear to have been the secret doctrines which were cautiously whispered in the gardens of the Academy; and which, according to the more recent disciples of Plato, could not be perfectly understood till after an assiduous study of thirty years.(12)
taught in the scool of Alexandria. Before Christ 300.
The arms of the Macedonians diffused over Asia and Egypt the language and learning of Greece; and the theological system of Plato was taught, with less reserve, and perhaps with some improvements, in the celebrated school of Alexandria. (13) A numerous colony of Jews had been invited, by the favour of the Ptolemies, to settle in their new capital.(14) While the bulk of the nation practised the legal ceremonies, and pursued the lucrative occupations of commerce, a few Hebrews of a more liberal spirit devoted their lives to religious and philosophical contemplation. (15) They cultivated with diligence, and embraced with ardour, the theological system of the Athenian sage. But their national pride would have been mortified by a fair confession of their former poverty: and they boldly marked, as the sacred inheritance of their ancestors, the gold and jewels which they had so lately stolen from their Egyptian masters. One hundred years before the birth of Christ, a philosophical treatise, which manifestly betrays the style and sentiments of the school of Plato, was produced by the Alexandrian Jews, and unanimously received as a genuine and valuable relic of the inspired Wisdom of Solomon. (16) A similar union of the Mosaic faith and the Grecian philosophy distinguishes the works of Philo, which were composed, for the most part, under the reign of Augustus.(17) The material soul of the universe(18) might offend the piety of the Hebrews; but they applied the character of the Logos to the Jehovah of Moses and the Patriarchs; and the Son of God was introduced upon earth, under a visible and even human appearance, to perform those familiar offices which seem incompatible with the nature and attributes of the Universal Cause.(19)
Revealed by the Apostle St John, A.D. 97.
The eloquence of Plato, the name of Solomon, the authority of the school of Alexandria, and the consent of the Jews and Greeks, were insufficient to establish the truth of a mysterious doctrine, which might please, but could not satisfy, a rational mind. A prophet, or apostle, inspired by the Deity, can alone exercise a lawful dominion over the faith of mankind: and the theology of Plato might have been for ever confounded with the philosophical visions of the Academy, the Porch, and the Lyccum, if the name and divine attributes of the Logos had not been confirmed by the celestial pen of the last and most sublime of the Evangelists. (20) The Christian Revelation, which was consummated under the reign of Nerva, disclosed to the world the amazing secret, that the LOGOS, who was with God from the beginning, and was God, who had made all things, and for whom all things had been made, was incarnate in the person of Jesus of Nazareth; who had been born of a virgin, and suffered death on the cross. Besides the general design of fixing on a perpetual basis the divine honours of Christ, the most ancient and respectable of the ecclesiastical writers have ascribed to the evangelic theologian a particular intention to confute two opposite heresies, which disturbed the peace of the primitive church.(21)
The Ebionites and Docetes I. The faith of the Ebionites, (22) perhaps of the Nazarenes,(23) was gross and imperfect. They revered Jesus as the greatest of the prophets, endowed with supernatural virtue and power. They ascribed to his person and to his future reign all the predictions of the Hewbrew oracles which relate to the spiritual and everlasting kingdom of the promised Messiah. (24) Some of them might confess that he was born of a virgin; but they obstinately rejected the preceding existence and divine perfections of the logos, or Son of God, which are so clearly defined in the Gospel of St. John. About fifty years afterwards, the Ebionites, whose errors are mentioned by Justin Martyr, with less severity than they seem to deserve, (25) formed a very inconsiderable portion of the Christian name. II. The Gnostics, who were distinguished by the epithet of Docetes, deviated into the contrary extreme, and betrayed the human, while they asserted the divine nature of Christ. Educated in the school of Plato, accustomed to the sublime idea of the Logos, they readily conceived that the brightest Aeon, or Emanation of the Deity, might assume the outward shape and visible appearances of a mortal;(26) but they vainly pretended that the imperfections of matter are incompatible with the purity of a celestial substance. While the blood of Christ yet smoked on Mount Calvary, the Docetes invented the impious and extravagant hypothesis, that, instead of issuing from the womb of the Virgin,(27) he had descended on the banks of the Jordan in the form of perfect manhood; that he had imposed on the senses of his enemies and of his disciples; and that the ministers of Pilate had wasted their impotent rage on an airy phantom, who seemed to expire on the cross, and, after three days, to rise from the dead.(28)
Mysterious nature of the Trinity.
The divine sanction which the Apostle had bestowed on the fundamental principle of the theology of Plato encouraged the learned proselytes of the second and third centuries to admire and study the writings of the Athenian sage, who had thus marvellously anticipated one of the most surprising discoveries of the Christian revelation. The respectable name of Plato was used by the orthodox,(29) and abused by the heretics,(30) as the common support of truth and error: the authority of his skilful commentators and the science of dialectics were employed to justify the remote consequences of his opinions, and to supply the discreet silence of the inspired writers. The same subtle and profound questions concerning the nature, the generation, the distinction, and the equality of the three divine persons of the mysterious Triad, or Trinity,(31) were agitated in the philosophical and in the Christian schools of Alexandria. An eager spirit of curiosity urged them to explore the secrets of the abyss; and the pride of the professors and of their disciples was satisfied with the science of words. But the most sagacious of the Christian theologians, the great Athanasius himself, has candidly confessed (32) that, whenever he forced his understanding to meditate on the divinity of the Logos, his toilsome and unavailing efforts recoiled on themselves; that the more he thought, the less he comprehended; and the more he wrote, the less capable was he of expressing his thoughts. In every step of the inquiry we are compelled to feel and acknowledge the immeasurable disproportion between the size of the object and the capacity of the human mind. We may strive to abstract the notions of time, of space, and of matter, which so closely adhere to all the perceptions of our experimental knowledge. But as soon as we presume to reason of infinite substance, of spiritual generation, as often as we deduce any positive conclusions from a negative idea, we are involved in darkness, perplexity, and inevitable contradiction. As these difficulties arise from the nature of the subject, they oppress, with the same insuperable weight, the philosophic and the theological disputant; but we may observe two essential and peculiar circumstances which discriminated the doctrines of the catholic church from the opinions of the Platonic school.
-snip-
More at above link : This book is a masterpiece ...
Athanasius is considered the 'father' of the Trinity. due to his advocacy of the system .... but even HE was troubled by it's inconstant notions ....