What did God create on the first day?
On the first day God created the light (LX VII. 4).
On the second day?
The firmament (LXVIII. 1).
On the third day?
On the fourth day?
On this day God created the sun, the moon, and the stars (LXX. 1).
On the fifth day?
The fishes and the birds (LXXI.). On the sixth day?
On this day God created the beasts of the earth; and lastly He created man (LXXII.).
How do we know that God thus created the world such as we see it?
We know that God thus created the world such as we see it because He Himself has said so.
Where does God say that He created the world in this wise and such as we see it?
In the first chapter of Genesis, at the very beginning of the Holy Scriptures, God tells us that He made the world in this wise and such as we see it.
Are the sciences in accord with this first chapter of Genesis?
There is no doubt that sciences worthy of the name are and will always be in accord with the first chapter of Genesis.
Why do you say sciences worthy of the name?
Because sciences worthy of the name give true explanations of things as they are; but no science knows better than God Himself the things that He Himself made; and it is God who tells us how He made them in the first chapter of Genesis.
Can there be then any contradiction between the sciences and Holy Scripture on the subject of the creation of the material world?
No, it is not possible for any contradiction to exist between the sciences worthy of the name and Holy Scripture on the subject of the creation of the material world (LXVII.-LXXIV.).
(Next - XIII. OF MAN: HIS NATURE; HIS SPIRITUAL AND IMMORTAL SOUL)
Pegues OP, R P Thomas. Catechism of the "Summa Theologica" of Saint Thomas Aquinas for the Use of the Faithful (pp. 59-62). Veritatis Splendor Publications. Kindle Edition.