Though Hilary was not its inventor, and was forced by the large part played by Old Testament exegesis in the Arian controversy to employ it, whether he would or not [168] , yet it is certain that his hearty, though not indiscriminate [169] , acceptance of the method led to its general adoption in the West. Tertullian and Cyprian had made no great use of such speculations; Irenæus probably had little influence. It was the introduction of Origen's thought to Latin Christendom by Hilary and his contemporaries which set the fashion, and none of them can have had such influence as Hilary himself. It is a strange irony of fate that so deep and original a thinker should have exerted his most permanent influence not through his own thoughts, but through this dubious legacy which he handed on from Alexandria to Europe. Yet within certain limits, it was a sound and, for that age, even a scientific method; and Hilary might at least plead that he never allowed the system to be his master, and that it was a means which enabled him to derive from Scriptures which otherwise, to him, would be unprofitable, some treasure of true and valuable instruction. It never moulds his thoughts; at the most, he regards it as a useful auxiliary. No praise can be too high for his wise and sober marshalling not so much of texts as of the collective evidence of Scripture concerning the relation of the Father and the Son in the De Trinitate; and if his Christology be not equally convincing, it is not the fault of his method, but of its application [170] . We cannot wonder that Hilary, who owed his clear dogmatic convictions to a careful and independent study of Scripture, should have wished to lead others to the same source of knowledge. He couples it with the Eucharist as a second Table of the Lord, a public means of grace, which needs, if it is to profit the hearer, the same preparation of a pure heart and life [171] . Attention to the lessons read in church is a primary duty, but private study of Scripture is enforced with equal earnestness [172] . It must be for all, as Hilary had found it for himself, a privilege as well as a duty.
His sense of the value of Scripture is heightened by his belief in the sacredness of language. Names belong inseparably to the things which they signify; words are themselves a revelation. This is a lesson learnt from Origen; and the false antithesis between the nature and the name of God, of which, according to the Arians, Christ had the latter only, made it of special use to Hilary [173] . But if this high dignity belongs to every statement of truth, there is the less need for technical terms of theology. The rarity of their occurrence in the pages of Hilary has already been mentioned. Trinity' [174] is almost absent, and Person' [175] hardly more common, he prefers, by a turn of language which would scarcely be seemly in English, to speak of the embodied' Christ and of His Embodiment,' though Latin theology was already familiar with the Incarnation [176] .' In fact, it would seem that he had resolved to make himself independent of technical terms and of such lines of thought as would require them. But he is never guilty of confusion caused by an inadequate vocabulary. He has the literary skill to express in ordinary words ideas which are very remote from ordinary thought, and this at no inordinate length. No one, for instance, has developed the idea of the mutual indwelling of Father and Son more fully and clearly than he; yet he has not found it necessary to employ or devise the monstrous circuminsession' or perichoresis' of later theology. And where he does use terms of current theology, or rather metaphysic, he shews that he is their master, not their slave. The most important idea of this kind which he had to express was that of the Divine substance. The word essence' is entirely rejected [177] ; substance' and nature' are freely used as synonyms, but in such alternation that both of them still obviously belong to the sphere of literature, and not of science. They are twice used as exact alternatives, for the avoidance of monotony, in parallel clauses of Trin. vi. 18, 19. So also the nature of fire in vii. 29 is not an abstraction; and in ix. 36 fin. the Divine substance and nature are equivalents. These are only a few of many instances [178] . Here, as always, there is an abstention from abstract thoughts and terms, which indicates, on the part of a student of philosophy and of philosophical theology, a deliberate narrowing of his range of speculation. We may illustrate the purpose of Hilary by comparing his method with that of the author of a treatise on Astronomy without Mathematics. But some part of his caution is probably due to his sense of the inadequacy of the terms with which Latin theology was as yet equipped, and of the danger, not only to his readers' faith, but to his own reputation for orthodoxy, which might result from ingenuity in the employment or invention of technical language.
Though, as we have seen, the contemplative state is not the ultimate happiness of man, yet the knowledge of God is essential to salvation [179] ; man, created in God's image, is by nature capable of, and intended for, such knowledge, and Christ came to impart it, the necessary condition on the side of humanity being purity of mind [180] , and the result the elevation of man to the life of God. Hilary does not shrink from the emphatic language of the Alexandrian school, which spoke of the deification' of man; God, he says, was born to be man, in order that man might be born to be God [181] . If this end is to be attained, obviously what is accepted as knowledge must be true; hence the supreme wickedness of heresy, which destroys the future of mankind by palming upon them error for truth; the greater their dexterity the greater, because the more deliberate, their crime. And Hilary was obviously convinced that his opponents had conceived this nefarious purpose. It is not in the language of mere conventional polemics, but in all sincerity, that he repeatedly describes them as liars who cannot possibly be ignorant of the facts which they misrepresent, inventors of sophistical arguments and falsifiers of the text of Scripture, conscious that their doom is sealed, and endeavouring to divert their minds from the thought of future misery by involving others in their own destruction [182] . He fully recognises the ability and philosophical learning displayed by them; it only makes their case the worse, and, after all, is merely folly. But it increases the difficulties of the defenders of the Faith. For though man can and must know God, Who, for His part, has revealed Himself, our knowledge ought to consist in a simple acceptance of the precise terms of Scripture. The utmost humility is necessary; error begins when men grow inquisitive. Our capacity for knowledge, as Hilary is never tired of insisting, is so limited that we ought to be content to believe without defining the terms of our belief. For weak as intellect is, language, the instrument which it must employ, is still less adequate to so great a task [183] . Heresy has insisted upon definition, and the true belief is compelled to follow suit [184] . Here again, in the heretical abuse of technical terms and of logical processes, we find a reason for the almost ostentatious simplicity of diction which we often find in Hilary's pages. He evidently believed that it was possible for us to apprehend revealed truth and to profit fully by it, without paraphrase or other explanation. In the case of one great doctrine, as we shall see, no necessities of controversy compelled him to develope his belief; if he had had his way, the Faith should never have been stated in ampler terms than I believe in the Holy Ghost.'
In a great measure he has succeeded in retaining this simplicity in regard to the doctrine of God. He had the full Greek sense of the divine unity; there is no suggestion of the possession by the Persons of the Trinity of contrasted or complementary qualities. The revelation he would defend is that of God, One, perfect, infinite, immutable. This absolute God has manifested Himself under the name He that is,' to which Hilary constantly recurs. It is only through His own revelation of Himself that God can be known. But here we are faced by a difficulty; our reason is inadequate and tends to be fallacious. The argument from analogy, which we should naturally use, cannot be a sufficient guide, since it must proceed from the finite to the infinite. Hilary has set this forth with great force and frequency, and with a picturesque variety of illustration. Again, our partial glimpses of the truth are often in apparent contradiction; when this is the case, we need to be on our guard against the temptation to reject one as incompatible with the other. We must devote an equal attention to each, and believe without hesitation that both are true. The interest of the De Trinitate is greatly heightened by the skill and courage with which Hilary will handle some seeming paradox, and make the antithesis of opposed infinities conduce to reverence for Him of Whom they are aspects. And he never allows his reader to forget the immensity of his theme; and here again the skill is manifest with which he casts upon the reader the same awe with which he is himself impressed.
Of God as Father Hilary has little that is new to say. He is called Father in Scripture; therefore He is Father and necessarily has a Son. And conversely the fact that Scripture speaks of God the Son is proof of the fatherhood. In fact, the name Son' contains a revelation so necessary for the times that it has practically banished that of the Word,' which we should have expected Hilary, as a disciple of Origen, to employ by preference [185] . But since faith in the Father alone is insufficient for salvation [186] , and is, indeed, not only insufficient but actually false, because it denies His fatherhood in ignoring the consubstantial Son, Hilary's attention is concentrated upon the relation between these two Persons. This relation is one of eternal mutual indwelling, or perichoresis,' as it has been called, rendered possible by Their oneness of nature and by the infinity of Both. The thought is worked out from such passages as Isaiah xlv. 14, St. John xiv. 11, with great cogency and completeness, yet always with due stress laid on the incapacity of man to comprehend its immensity. Hilary advances from this scriptural position to the profound conception of the divine self-consciousness as consisting in Their mutual recognition. Each sees Himself in His perfect image, which must be coeternal with Himself. In Hilary this is only a hint, one of the many thoughts which the urgency of the conflict with Arianism forbade him to expand. But Dorner justly sees in it a kind of speculative construction of the doctrine of the Trinity, out of the idea of the divine self-consciousness [187] .'
The Arian controversy was chiefly waged over the question of the eternal generation of the Son. By the time that Hilary began to write, every text of Scripture which could be made applicable to the point in dispute had been used to the utmost. There was little or nothing that remained to be done in the discovery or combination of passages. Of that controversy Athanasius was the hero; the arguments which he used and those which he refuted are admirably set forth in the introduction to the translation of his writings in this series. In writing the De Trinitate, so far as it dealt directly with the original controversy, it was neither possible nor desirable that Hilary should leave the beaten path. His object was to provide his readers with a compendious statement of ascertained truth for their own guidance, and with an armoury of weapons which had been tried and found effective in the conflicts of the day. It would, therefore, be superfluous to give in this place a detailed account of his reasonings concerning the generation of the Son, nor would such an account be of any assistance to those who have his writings in their hands. Hilary's treatment of the Scriptural evidence is very complete, as was, indeed, necessary in a work which was intended as a handbook for practical use. The Father alone is unbegotten; the Son is truly the Son, neither created nor adopted. The Son is the Creator of the worlds, the Wisdom of God, Who alone knows the Father, Who manifested God to man in the various Theophanies of the Old Testament. His birth is without parallel, inasmuch as other births imply a previous non-existence, while that of the Son is from eternity. For the generation on the part of the Father and the birth on the part of the Son are not connected as by a temporal sequence of cause and effect, but exactly coincide in a timeless eternity [188] . Hilary repudiates the possibility of illustrating this divine birth by sensible analogies; it is beyond our understanding as it is beyond time. Nor can we wonder at this, seeing that our own birth is to us an insoluble mystery. The eternal birth of the Son is the expression of the eternal nature of God. It is the nature of the One that He should be Father, of the Other that He should be Son; this nature is co-eternal with Themselves, and therefore the One is co-eternal with the Other. Hence Athanasius had drawn the conclusion that the Son is by nature and not by will' [189] ; not that the will of God is contrary to His nature, but that (if the words may be used) there was no scope for its exercise in the generation of the Son, which came to pass as a direct consequence of the Divine nature. Such language was a natural protest against an Arian abuse; but it was a departure from earlier precedent and was not accepted by that Cappadocian school, more true to Alexandrian tradition than Athanasius himself, with which Hilary was in closest sympathy. In their eyes the generation of the Son must be an act of God's will, if the freedom of Omnipotence, for which they were jealous, was to be respected; and Hilary shared their scruples. Not only in the De Synodis but in the De Trinitate [190] he assigns the birth of the Son to the omnipotence, the counsel and will of God acting in co-operation with His nature. This two-fold cause of birth is peculiar to the Son; all other beings owe their existence simply to the power and will, not to the nature of God [191] . Such being the relation between Father and Son, it is obvious that They cannot differ in nature. The word birth,' by which the relation is described, indicates the transmission of nature from parent to offspring; and this word is, like Father' and Son,' an essential part of the revelation. The same divine nature or substance exists eternally and in equal perfection in Both, un-begotten in the Father, begotten in the Son. In fact, the expression, Only-begotten God' may be called Hilary's watchword, with such peculiar abundance [192] ' does it occur in his writings, as in those of his Cappadocian friends. But, though the Son is the Image of the Father, Hilary in his maturer thought, when free from the influence of his Asiatic allies, is careful to avoid using the inadequate and perilous term likeness' to describe the relation [193] . Such being the birth, and such the unity of nature, the Son must be very God. This is proved by all the usual passages of the Old Testament, from the Creation, onwards. These are used, as by the other Fathers, to prove that the Son has not the name only, but the reality, of Godhead; the reality corresponding to the nature. All things were made through Him out of nothing; therefore He is Almighty as the Father is Almighty. If man is made in the image of Both, if one Spirit belongs to Both, there can be no difference of nature between the Two. But They are not Two as possessing one nature, like human father and son, while living separate lives. God is One, with a Divinity undivided and indivisible [194] ; and Hilary is never weary of denying the Arian charge that his creed involved the worship of two Gods. No analogies from created things can explain this unity. Tree and branch, fire and heat, source and stream can only illustrate Their inseparable co-existence; such comparisons, if pressed, lead inevitably to error. The true unity of Father and Son is deeper than this; deeper also than any unity, however perfect, of will with will. For it is an eternal mutual indwelling, Each perfectly corresponding with and comprehending and containing the Other, and Himself in the Other; and this not after the manner of earthly commingling of substances or exchange of properties. The only true comparison that can be made is with the union between Christ, in virtue of His humanity, and the believer [195] ; such is the union, in virtue of the Godhead, between Father and Son. And this unity extends inevitably to will and action, since the Father is acting in all that the Son does, the Son is acting in all that the Father does; he that hath seen Me hath seen the Father.' This doctrine reconciles all our Lord's statements in the Gospel of St. John concerning His own and His Father's work.