St. John Damascene: "The soul, accordingly, is a living essence"

"THE SOUL, accordingly, is a living essence, simple, incorporeal, invisible in its proper nature to bodily eyes, immortal, reasoning and intelligent, formless, making use of an organised body, and being the source of its powers of life, and growth, and sensation, and generation , mind being but its purest part and not in any wise alien to it; (for as the eye to the body, so is the mind to the soul); further it enjoys freedom and volition and energy, and is mutable, that is, it is given to change, because it is created. All these qualities according to nature it has received of the grace of the Creator, of which grace it has received both its being and this particular kind of nature."

~St. John Damascene: Exposition of the Orthodox Faith, Bk. II, Chap 12.

St. Augustine: Of Christ's Ascension into Heaven

"WE BELIEVE that He Ascended into Heaven, which place of blessedness He has likewise promised unto us, saying, They shall be as the angels in the heavens, in that city which is the mother of us all, the Jerusalem eternal in the heavens. But it is wont to give offense to certain parties, either impious Gentiles or heretics, that we should believe in the assumption of an earthly body into heaven. The Gentiles, however, for the most part, set themselves diligently to ply us with the arguments of the philosophers, to the effect of affirming that there cannot possibly be anything earthly in heaven. For they know not our Scriptures, neither do they understand how it has been said, It is sown an animal body, it is raised a spiritual body. For thus it has not been expressed, as if body were turned into spirit and became spirit; inasmuch as at present, too, our body, which is called animal (animale), has not been turned into soul and become soul (anima). But by a spiritual body is meant one which has been made subject to spirit in such wise that it is adapted to a heavenly habitation, all frailty and every earthly blemish having been changed and converted into heavenly purity and stability. This is the change concerning which the apostle likewise speaks thus: We shall all rise, but we shall not all be changed. And that this change is made not unto the worse, but unto the better, the same [apostle] teaches, when he says, And we shall be changed. But the question as to where and in what manner the Lord's body is in heaven, is one which it would be altogether over-curious and superfluous to prosecute. Only we must believe that it is in heaven. For it pertains not to our frailty to investigate the secret things of heaven, but it does pertain to our faith to hold elevated and honorable sentiments on the subject of the dignity of the Lord's body."

~St. Augustine: Of Faith and the Creed, Chap. VI. (A discourse delivered before a council of the whole North African Episcopate assembled at Hippo-Regius.)

No. 38 Scenes from the Life of Christ: 22. Ascension, 

by Giotto di Bonde. Fresco, 1304-06;
Cappella Scrovegni (Arena Chapel), Padua.

St. Augustine: "The gift of a rational soul"

“MAN is a noble being created to the image and likeness of God, not insofar as he is housed in a mortal body, but in that he is superior to brute beasts because of the gift of a rational soul.”

~St. Augustine:  De Doctrina Christiana (On Christian Doctrine), 1, 22, 52.

Tertullian: "The soul also begins from conception"

"IN our case, a murder being once for all forbidden, we may not destroy even the fetus in the womb, while as yet the human being derives blood from the other parts of the body for its sustenance. To hinder a birth is merely a speedier man-killing; nor does it matter whether you take away a life that is born, or destroy one that is coming to birth. That is a man which is going to be one; you have the fruit already in its seed." --Apology, Ch. 9, v. 8. (A.D. 197)

"ACCORDINGLY, among surgeons' tools there is a certain instrument, which is formed with a nicely-adjusted flexible frame for opening the uterus first of all, and keeping it open; it is further furnished with an annular blade,  by means of which the limbs within the womb are dissected with anxious but unfaltering care; its last appendage being a blunted or covered hook, wherewith the entire fœtus is extracted  by a violent delivery. There is also (another instrument in the shape of) a copper needle or spike, by which the actual death is managed in this furtive robbery of life: they give it, from its infanticide function, the name of embruosphaktes [ἐμβρυοσφάκτης], the slayer of the infant, which was of course alive." --Treatise on the Soul, Chap. 25; (A.D. 210)

"HOW, then, is a living being conceived? Is the substance of both body and soul formed together at one and the same time? Or does one of them precede the other in natural formation? We indeed maintain that both are conceived, and formed, and perfectly simultaneously, as well as born together; and that not a moment's interval occurs in their conception, so that, a prior place can be assigned to either.  Judge, in fact, of the incidents of man's earliest existence by those which occur to him at the very last. As death is defined to be nothing else than the separation of body and soul,  life, which is the opposite of death, is susceptible of no other definition than the conjunction of body and soul. If the severance happens at one and the same time to both substances by means of death, so the law of their combination ought to assure us that it occurs simultaneously to the two substances by means of life. Now we allow that life begins with conception, because we contend that the soul also begins from conception; life taking its commencement at the same moment and place that the soul does;" --Treatise on the Soul, Chap. 27.

"THE law of Moses, indeed, punishes with due penalties the man who shall cause abortion[Ex. 21:22–24], inasmuch as there exists already the rudiment of a human being, which has imputed to it even now the condition of life and death, since it is already liable to the issues of both, although, by living still in the mother, it for the most part shares its own state with the mother." --Treatise on the Soul, Chap. 37.

~Tertullian (Quintus Septimius Florens Tertullianus)