What is the "deep" in traditional Catholic understanding?

[Ragnarok]

"The earth was without form, and void; and darkness [a]was on the face of the deep. And the Spirit of God was hovering over the face of the waters."

What is this "deep" according to traditional Catholic understanding? These "waters" of "void and darkness"? Did God create it? Is it just nothingness? Did God create this nothingness?

[Jayne]

This is not an answer to your question, but something I find useful background for discussions of Creation.  So I'm just putting it out here:

Abbreviations:

ASS: Acta Sedis Sanctae; AAS: Acta Apostolicae Sedis; EB: Enchiridion Biblicum; Dz: Denzinger

Pope Pius X, Motu Proprio Praestantia Scripturae, 18 Nov. 1907 (ASS [1907] 724ff; EB nn. 278f; Dz 2113f): "We now declare and expressly enjoin that all Without exception are bound by an obligation of conscience to submit to the decisions of the Pontifical Biblical Commission, whether already issued or to be issued hereafter, exactly as to the decrees of the Sacred Congregations which are on matters of doctrine and approved by the Pope; nor can anyone who by word or writing attacks the said decrees avoid the note both of disobedience and of rashness or be therefore without grave fault."



On the Mosaic Authorship of the Pentateuch

June 27, 1906 (ASS 39 [1906-07] 377f; EB 174ff; Dz 1997ff)

I: Are the arguments gathered by critics to impugn the Mosaic authorship of the sacred hooks designated by the name of the Pentateuch of such weight in spite of the cumulative evidence of many passages of both Testaments, the unbroken unanimity of the Jewish people, and furthermore of the constant tradition of the Church besides the internal indications furnished by the text itself, as to justify the statement that these books are not of Mosaic authorship but were put together from sources mostly of post-Mosaic date?
Answer: In the negative.

II: Does the Mosaic authorship of the Pentateuch necessarily imply a production of the whole work of such a character as to impose the belief that each and every word was written by Moses' own hand or was by him dictated to secretaries ; or is it a legitimate hypothesis that he conceived the work himself under the guidance of divine inspiration and then entrusted the writing of it to one or more persons, with the understanding that they reproduced his thoughts with fidelity and neither wrote nor omitted anything contrary to his will, and that finally the work composed after this fashion was approved by Moses, its principal and inspired author, and was published under his name?
Answer: In the negative to the first and in the affirmative to the second part.

III: Without prejudice to the Mosaic authorship of the Pentateuch, may it be granted that in the composition of his work Moses used sources, written documents namely or oral traditions, from which in accordance with the special aim he entertained and under the guidance of divine inspiration he borrowed material and inserted it in his work either word for word or in substance, either abbreviated or amplified?
Answer: In the affirmative.

IV: Subject to the Mosaic authorship and the integrity of the Pentateuch being substantially safeguarded, may it be admitted that in the protracted course of centuries certain modifications befell it, such as : additions made after the death of Moses by an inspired writer, or glosses and explanations inserted in the text, certain words and forms changed from archaic into more recent speech, finally incorrect readings due to the fault of scribes which may be the subject of inquiry and judgement according to the laws of textual criticism?
Answer In the affirmative, saving the judgement of the Church.

Concerning the Historical Character of the First Three Chapters of Genesis

June 30, 1909 (AAS 1 [1909] 567ff; EB 332ff; Dz 2121ff)

I: Do the various exegetical systems excogitated and defended under the guise of science to exclude the literal historical sense of the first three chapters of Genesis rest on a solid foundation?
Answer: In the negative.

II: Notwithstanding the historical character and form of Genesis, the special connection of the first three chapters with one another and with the following chapters, the manifold testimonies of the Scriptures both of the Old and of the New Testaments, the almost unanimous opinion of the holy Fathers and the traditional view which the people of Israel also has handed on and the Church has always held, may it be taught that: the aforesaid three chapters of Genesis Contain not accounts of actual events, accounts, that is, which correspond to objective reality and historical truth, but, either fables derived from the mythologies and cosmogonies of ancient peoples and accommodated by the sacred writer to monotheistic doctrine after the expurgation of any polytheistic error; or allegories and symbols without any foundation in objective reality proposed under the form of history to inculcate religious and philosophical truths; or finally legends in part historical and in part fictitious freely composed with a view to instruction and edification?
Answer: In the negative to both parts.

III: In particular may the literal historical sense be called in doubt in the case of facts narrated in the same chapters which touch the foundations of the Christian religion: as are, among others, the creation of all things by God in the beginning of time; the special creation of man; the formation of the first woman from the first man; the unity of the human race; the original felicity of our first parents in the state of justice, integrity, and immortality; the command given by God to man to test his obedience; the transgression of the divine command at the instigation of the devil under the form of a serpent; the degradation of our first parents from that primeval state of innocence; and the promise of a future Redeemer?
Answer: In the negative.

IV: In the interpretation of those passages in these chapters which the Fathers and Doctors understood in different manners without proposing anything certain and definite, is it lawful, without prejudice to the judgement of the Church and with attention to the analogy of faith, to follow and defend the opinion that commends itself to each one?
Answer: In the affirmative.

V: Must each and every word and phrase occurring in the aforesaid chapters always and necessarily be understood in its literal sense, so that it is never lawful to deviate from it, even when it appears obvious that the diction is employed in an applied sense, either metaphorical or anthropomorphical, and either reason forbids the retention or necessity imposes the abandonment of the literal sense?
Answer: In the negative.

VI: Provided that the literal and historical sense is presupposed, may certain passages in the same chapters, in the light of the example of the holy Fathers and of the Church itself, be wisely and profitably interpreted in an allegorical and prophetic sense?
Answer: In the affirmative.

VII: As it was not the mind of the sacred author in the composition of the first chapter of Genesis to give scientific teaching about the internal Constitution of visible things and the entire order of creation, but rather to communicate to his people a popular notion in accord with the current speech of the time and suited to the understanding and capacity of men, must the exactness of scientific language be always meticulously sought for in the interpretation of these matters?
Answer: In the negative.

VIII : In the designation and distinction of the six days mentioned in the first chapter of Genesis may the word Yom (day) be taken either in the literal sense for the natural day or in an applied sense for a certain space of time, and may this question be the subject of free discussion among exegetes?
Answer: In the affirmative.

http://www.catholicapologetics.info/scripture/oldtestament/commission.htm

[TerrorDæmonum]

What is this "deep" according to traditional Catholic understanding? These "waters" of "void and darkness"? Did God create it? Is it just nothingness? Did God create this nothingness?

Another translation of "deep" would be "abyss".

The mysteries of scripture are not always clear. One could interpret these aspect of Genesis as referring to the creation of the earth and seas and the sun, or one could view it in a higher sense.

The Haydock commentary focuses on the material creation of the world we know on this particular verse.

A more spiritual understanding is with St Augustine:

Chapter 32.? Of the Opinion that the Angels Were Created Before the World.

But if some one oppose our opinion, and say that the holy angels are not referred to when it is said, "Let there be light, and there was light;" if he suppose or teach that some material light, then first created, was meant, and that the angels were created, not only before the firmament dividing the waters and named "the heaven," but also before the time signified in the words, "In the beginning God created the heaven and the earth;" if he allege that this phrase, "In the beginning," does not mean that nothing was made before (for the angels were), but that God made all things by His Wisdom or Word, who is named in Scripture "the Beginning," as He Himself, in the gospel, replied to the Jews when they asked Him who He was, that He was the Beginning; ? I will not contest the point, chiefly because it gives me the liveliest satisfaction to find the Trinity celebrated in the very beginning of the book of Genesis. For having said "In the Beginning God created the heaven and the earth," meaning that the Father made them in the Son (as the psalm testifies where it says, "How manifold are Your works, O Lord! In Wisdom have You made them all" ), a little afterwards mention is fitly made of the Holy Spirit also. For, when it had been told us what kind of earth God created at first, or what the mass or matter was which God, under the name of "heaven and earth," had provided for the construction of the world, as is told in the additional words, "And the earth was without form, and void; and darkness was upon the face of the deep," then, for the sake of completing the mention of the Trinity, it is immediately added, "And the Spirit of God moved upon the face of the waters." Let each one, then, take it as he pleases; for it is so profound a passage, that it may well suggest, for the exercise of the reader's tact, many opinions, and none of them widely departing from the rule of faith. At the same time, let none doubt that the holy angels in their heavenly abodes are, though not, indeed, co-eternal with God, yet secure and certain of eternal and true felicity. To their company the Lord teaches that His little ones belong; and not only says, "They shall be equal to the angels of God," Matthew 22:30 but shows, too, what blessed contemplation the angels themselves enjoy, saying, "Take heed that you despise not one of these little ones: for I say unto you, that in heaven their angels do always behold the face of my Father which is in heaven." Matthew 18:10

If you read Genesis as a simple account of material creation, then yes, God made everything. If you read it with the idea that the "light" and the "dark" is a reference to the spiritual realm and the "dark" being evil angels who at the beginning rebelled, then God created those angels, but God did not create evil.

Saint Thomas treats the subject as one of creation and the distinction of creation, and the nature of evil as being not a being:

Article 1. Whether evil is a nature?

On the contrary, Dionysius says (Div. Nom. iv), "Evil is neither a being nor a good."

I answer that, One opposite is known through the other, as darkness is known through light. Hence also what evil is must be known from the nature of good. Now, we have said above that good is everything appetible; and thus, since every nature desires its own being and its own perfection, it must be said also that the being and the perfection of any nature is good. Hence it cannot be that evil signifies being, or any form or nature. Therefore it must be that by the name of evil is signified the absence of good. And this is what is meant by saying that "evil is neither a being nor a good." For since being, as such, is good, the absence of one implies the absence of the other.

With this in mind, God created everything, but the distinction of evil from good and the distinction of dark from light don't mean "evil" and "dark" are created, rather, they are the absence of good and light.