Like Waterland, and indeed all defenders of the Catholic doctrine, Horsley fully admits the difficulties and mysteriousness of his subject, 'but,' he asks, 'is Christianity clear of difficulties in any of the Unitarian schemes? Hath the Arian hypothesis no difficulty when it ascribes both the first formation and perpetual government of the Universe not to the Deity, but an inferior being? In the Socinian scheme is it no difficulty that the capacity of a mere man should contain that wisdom by which God made the universe?'[458]
Horsley rebukes his opponent in severe and dignified language for presuming to write on a subject on which, by his own confession, he was ignorant of what had been written. In reply to a passage in Horsley's 'Charge,' in which it was asserted that Priestley's opinions in general were the same as those propagated by Daniel Zuicker, and that his arguments were in essential points the same as Episcopius had used, Priestley had said that he had never heard of Zuicker, and knew little of Episcopius; he also let slip that he had only 'looked through' the ancient fathers and the writings of Bishop Bull, an unfortunate phrase, which Horsley is constantly casting in his teeth.[459] On the positive proofs of his own position, Horsley cites numerous passages from the ante-Nicene fathers. He contends that in the famous passage of Tertullian on which Priestley had laid so much stress, Tertullian meant by 'idiotæ,' not the general body of unlearned Christians, but some stupid people who could not accept the great mystery which was generally accepted by the Church. He shows that the Jews in Christ's time did believe in a Trinity, and expected the Second Person to come as their Messiah. He maintains that when Athanasius spoke of Jews who held the simple humanity of Christ, he meant what he said, viz., Jews simply, not Christian Jews, as Priestley asserted.
There is a fine irony in some of his remarks on Priestley's interpretations of Scripture. 'To others,' he says in his 'Charge,' 'who have not the sagacity to discern that the true meaning of an inspired writer must be the reverse of the natural and obvious sense of the expressions which he employs, the force of the conclusion that the Primitive Christians could not believe our Lord to be a mere man because the Apostles had told them He was Creator of the Universe (Colossians i. 15, 17) will be little understood.'[460] In the famous text which speaks of Christ as 'come in the flesh,' for 'come in the flesh' Priestley substitutes 'come of the flesh.' 'The one,' says Horsley, 'affirms an Incarnation, the other a mortal extraction. The first is St. John's assertion, the second Dr. Priestley's. Perhaps Dr. Priestley hath discovered of St. John, as of St. Paul, that his reasoning is sometimes inconclusive and his language inaccurate, and he might think it no unwarrantable liberty to correct an expression, which, as not perfectly corresponding with his own system, he could not entirely approve. It would have been fair to advertise his reader of so capital an emendation, an emendation for which no support is to be found in the Greek Testament or any variety of manuscripts.'[461] In a similar tone, he trusts 'that the conviction of the theological student that his philosophy is Plato's, and his creed St. John's, will alleviate the mortification he might otherwise feel in differing from Dr. Priestley.'[462]
One of the most important and interesting parts of Horsley's letters was that in which he discussed the old objection raised by Priestley that the Christian doctrine of the Trinity was borrowed from Plato. There is, and Horsley does not deny it, a certain resemblance between the Platonic and the Christian theories. The Platonist asserted three Divine hypostases, the Good Being (τἀγαθόν), the word or reason (λόγος or νοῦς), and the Spirit (ψυχή) that actuates or influences the whole system of the Universe (anima mundi), which had all one common Deity (τὸ θείον), and were eternal and necessarily existent.[463] Horsley can see no derogation to Christianity in the resemblance of this theory to that of the Christian Trinity. He thinks that the advocates of the Catholic Faith in modern times have been too apt to take alarm at the charge of Platonism. 'I rejoice,' he says, 'and glory in the opprobrium. I not only confess, but I maintain, not a perfect agreement, but such a similitude as speaks a common origin, and affords an argument in confirmation of the Catholic doctrine for its conformity to the most ancient and universal traditions.'[464] For was this idea of a Triad peculiar to Plato? or did it originate with him? 'The Platonists,' says Horsley, 'pretended to be no more than expositors of a more ancient doctrine which is traced from Plato to Parmenides; from Parmenides to his master of the Pythagorean sect; from the Pythagoreans to Orpheus, the earliest of Grecian mystagogues; from Orpheus to the secret lore of Egyptian priests in which the foundations of the Orphic theology were laid. Similar notions are found in the Persian and Chaldean theology; even in Roman superstition from their Trojan ancestors. In Phrygia it was introduced by Dardanus, who carried it from Samothrace.' In short, 'the Trinity was a leading principle in all ancient schools of philosophy and religion.'[465]
Not, of course, that Horsley approved of the attempts made at the close of the second century to meet the Platonists half-way by professing that the leading doctrines of the Gospel were contained in Plato's writings. He strongly condemned, e.g., the conceit of the Platonic Christians that the external display of the powers of the Son in the business of Creation is the thing intended in Scripture language under the figure of his generation. 'There is no foundation,' he thinks, 'in Holy Writ, and no authority in the opinions and doctrines of preceding ages. It betrayed some who were most wedded to it into the use of very improper language, as if a new relation between the First and Second Persons took place when the creative powers were first exerted.' He condemns 'the indiscretion of presuming to affix a determinate meaning upon a figurative expression of which no particular exposition can be drawn safely from Holy Writ.' 'But,' he adds, 'the conversion of an attribute into a person, whatever Dr. Priestley may imagine, is a notion to which they were entire strangers.' On the main question of the Trinity he asserts, in opposition to Dr. Priestley, that they were quite sound.
Adopting the same line of argument which Leslie had used before him, Horsley dexterously turns the supposed resemblance between Platonism and Christianity, which, as has been seen, he admits, into a plain proof that the doctrine of the Trinity cannot be such a contradiction as the Unitarians represented it to be.
The controversy between Priestley and Horsley brings us nearly to the close of the eighteenth century. There had been a considerable secession of English clergymen to the Unitarians,[466] and Horsley's masterly tracts were a very opportune defence of the Catholic doctrine. On one point he and his adversary thoroughly concurred—viz., that there could be no medium between making Christ a mere man and owning Him to be in the highest sense God. Arianism in its various forms had become by this time well-nigh obsolete in England. It was a happy thing for the Church that this point had been virtually settled. The alternative was now clearly set before English Churchmen—'Choose ye whom ye will serve; if Christ be God, follow him; if not, be prepared to give up all notions of a creature worship.' The Unitarians at the close of the eighteenth century all took their stand on this issue. Such rhapsodies as those which were indulged in by early Socinians as well as Arians were now unheard. The line of demarcation was strictly drawn between those who did and those who did not believe in the true Godhead and distinct personality of the Second and Third Persons of the Blessed Trinity, so that from henceforth men might know on what ground they were standing.
Here the sketch of this famous controversy, which was certainly a marked feature of the eighteenth century, may fitly close. But a few general remarks in conclusion seem requisite.
And first as to the nomenclature. The name claimed by the anti-Trinitarians has, for want of a better, been perforce adopted in the foregoing pages. But in calling them Unitarians, we must do so under protest. The advocates of the Catholic doctrine might with equal correctness be termed, from one point of view, Unitarians, as they are from another point of view termed Trinitarians. For they believe in the Unity of God as firmly as they believe in the Trinity. And they hold that there is no real contradiction in combining those two subjects of belief; because the difficulty of reconciling the Trinity with the Unity of the Godhead in reality proceeds simply from our human and necessary incapacity to comprehend the nature of the union. Therefore they cannot for a moment allow to disbelievers in the Trinity the title of Unitarians, so as to imply that the latter monopolise the grand truth that 'the Lord our God is one Lord.' They consent reluctantly to adopt the term Unitarian because no other name has been invented to describe the stage at which anti-Trinitarians had arrived before the close of the eighteenth century. These latter, of course, differed essentially from the Arians of the earlier part of the century. Neither can they be properly termed Socinians, for Socinus, as Horsley justly remarks, 'though he denied the original divinity of Our Lord, was nevertheless a worshipper of Christ, and a strenuous asserter of his right to worship. It was left to others,' he adds, 'to build upon the foundation which Socinus laid, and to bring the Unitarian doctrine to the goodly form in which the present age beholds it.'[467] Indeed, the early Socinians would have denied to Dr. Priestley and his friends the title of Christians, and would have excommunicated them from their Society. 'Humanitarians' would be a more correct designation; but as that term is already appropriated to a very different signification, it is not available. For convenience' sake, therefore, the name of Unitarians must be allowed to pass, but with the proviso that so far from its holders being the sole possessors of the grand truth of the unity of the Godhead, they really, from the fact of their denying the divinity of two out of the three Persons in the Godhead, form only a very maimed and inadequate conception of the one God.
The outcry against all mystery, or, to use a modern phrase, the spirit of rationalism, which in a good or bad sense pervaded the whole domain of religious thought, orthodox and unorthodox alike during the eighteenth century, found its expression in one class of minds in Deism, in another in anti-Trinitarianism. But though both disavowed any opposition to real Christianity, yet both in reality allow no scope for what have been from the very earliest times to the present day considered essential doctrines of the Gospel. If the Deist strikes at the very root of Christianity by questioning the evidence on which it rests, no less does the Unitarian divest it of everything distinctive—of the divine condescension shown in God taking our nature upon Him, of the divine love shown in God's unseen presence even now in His Church by His Holy Spirit. Take away these doctrines, and there will be left indeed a residuum of ethical teaching, which some may please to call Christianity if they will; but it differs as widely from what countless thousands have understood and still understand by the term, as a corpse differs from a living man.