This position he had to defend against many assailants, and especially against the Eunomians.  These heretics maintained that the use of this term necessarily implied a beginning of the Essence of the Son, and they asked the orthodox to tell them when that beginning took place.  Gregory replies that the Generation of God the Son is beyond all time; pointing out that Paternity is an Essential attribute of God the Father, and therefore is as eternal as His Essence, so that there never was a time when He was not the Father, and consequently never a time when the Generation of the Son began.  He admits that there is a sense in which it is possible to say that the Son and the Spirit are not unoriginate, but then you must be careful not to use the word Origin in the sense of Beginning, but in that of Cause.  They derive Their Being eternally from the Father, and all Three Persons are coeternal together.  In respect of cause They are not unoriginate, but the cause is not necessarily prior in time to its effect, just as the Sun is not prior to its own light.  In respect of time, then, They may be said to be unoriginate, for the Sources of time cannot be subject to time.  “If the Father has not ceased to beget, His Generation is an imperfect one; and if He has ceased, He must have begun, for an end implies a beginning.”  “Not so,” says Gregory, “unless you are prepared to admit that what has no end has necessarily no beginning; and in that case what will you say about the Angels, or the human soul?  These will have no end; had either of them therefore no beginning?”  By a similar process of Reductio ad absurdum he dissipates all the quibbles of Eunomian sophistry, and lays down the orthodox Faith of the Church.  Then in the remainder of the Third and Fourth Orations he goes on to examine the Scriptural testimony adduced by his opponents, and to shew by a similar catena on the other side that the overwhelming preponderance of the authority of the Bible is clearly against them.  In connection with this point he lays down the canon that in the interpretation of Scripture in regard to our Lord, all expressions savouring of humility or weakness are to be referred to that pure Humanity which He assumed for our sake; while all that speaks of Majesty and Power belongs to His Godhead.