Sixth Ecumenical Council, 3rd Constantinople, The Definition of Faith

"Following the five holy Ecumenical Councils and the holy and approved Fathers, with one voice defining that our Lord Jesus Christ must be confessed to be very God and very man, one of the holy and consubstantial and life-giving Trinity, perfect in Deity and perfect in humanity, very God and very man, of a reasonable soul and human body subsisting; consubstantial with the Father as touching his Godhead and consubstantial with us as touching his manhood; in all things like unto us, sin only excepted; begotten of his Father before all ages according to his Godhead, but in these last days for us men and for our salvation made man of the Holy Ghost and of the Virgin Mary, strictly and properly the Mother of God according to the flesh; one and the same Christ our Lord the only-begotten Son of two natures unconfusedly, unchangeably, inseparably indivisibly to be recognized, the peculiarities of neither nature being lost by the union but rather the proprieties of each nature being preserved, concurring in one Person and in one subsistence, not parted or divided into two persons but one and the same only-begotten Son of God, the Word, our Lord Jesus Christ, according as the Prophets of old have taught us and as our Lord Jesus Christ himself hath instructed us, and the Creed of the holy Fathers hath delivered to us; defining all this we likewise declare that in him are two natural wills and two natural operations indivisibly, inconvertibly, inseparably, inconfusedly, according to the teaching of the holy Fathers. And these two natural wills are not contrary the one to the other (God forbid!) as the impious heretics assert, but his human will follows and that not as resisting and reluctant, but rather as subject to his divine and omnipotent will. For it was right that the flesh should be moved but subject to the divine will, according to the most wise Athanasius. For as his flesh is called and is the flesh of God the Word, so also the natural will of his flesh is called and is the proper will of God the Word, as he himself says: "I came down from heaven, not that I might do mine own will but the will of the Father which sent me!" where he calls his own will the will of his flesh, inasmuch as his flesh was also his own. For as his most holy and immaculate animated flesh was not destroyed because it was deified but continued in its own state and nature...so also his human will, although deified, was not suppressed, but was rather preserved according to the saying of Gregory Theologus: "His will [i.e., the Saviour’s] is not contrary to God but altogether deified."

We glorify two natural operations indivisibly, immutably, inconfusedly, inseparably in the same our Lord Jesus Christ our true God, that is to say a divine operation and a human operation"...For we will not admit one natural operation in God and in the creature, as we will not exalt into the divine essence what is created, nor will we bring down the glory of the divine nature to the place suited to the creature."

So by "two natures in one person" this is not to mean that the human nature participates in the essence of the Godhead or is somehow spatially brought into the Godhead, but as the human nature is hypostatized in the Logos it is in the Logos.