Taken literally, the Lateran IV definition of creation teaches that the proto-types of “all things” were created at the same time and directly by God from nothing previously existing. The evolution postulate affirms the contrary, i.e. that all things took much time to be produced and always from some preceding substance. The adverb simul in the creation definition meaning “all together” or “at the same time” excludes the idea of God spreading out creation of the various kinds over millions of years or having used evolution as a means of creating them. The concept of living beings gradually developing into other kinds of beings has no support from Holy Scripture, Tradition or the magisterial teaching of Lateran IV. Supporters of evolution felt obliged, therefore, to find some way of interpreting the Lateran definition to allow for long periods. They believed this was possible by going back to St. Augustine’s use of a word from the Latin translation of the Greek text of Sirach 18:1: He who lives forever created all things in common (RSV). The Greek word koinè meaning “in common” had been translated into Latin as simul in a pre-Vulgate Latin text which was later incorporated into the Vulgate: Qui vivit in aeternum creavit omnia simul. To understand how this extraordinary situation arose and why there was no theological reason to change the meaning of the Latin word simul in a thirteenth century conciliar text, one has to go back to the fifth century when St. Augustine wrote The Literal Meaning of Genesis. Commenting on the text of Sirach 18:1, St. Augustine wrote:
In this narrative of creation Holy Scripture has said of the Creator that He completed His works in six days, and elsewhere, without contradicting this, it has been written of the same Creator that He created all things together . . . Why then was there any need for six distinct days to be set forth in the narrative one after the other? The reason is that those who cannot understand the meaning of the text, He created all things together, cannot understand the meaning of the Scripture unless the narrative proceeds slowly step by step . . . For this Scripture text that narrates the works of God according to the days mentioned above, and that Scripture text that says God created all things together, are both true (emphasis added).
The bolded words in The Literal Meaning of Genesis text refer to Sirach 18:1. St. Augustine used this verse to defend his thesis that everything recorded in Genesis 1 and 2 had been created all together at the same moment. He chose it deliberately because the word used to translate the Greek koinè was the Latin simul (“at once” or “all together”) which corresponded with his belief in simultaneous creation.
The original Hebrew text is now lost. The Greek Septuagint version of Sirach 18:1 is:
The final Greek word koinè, which in English means “without exception” or “in common,” had been translated into Latin as simul which has the meaning of “simultaneously” or “all together.”
The Latin translation reads:
Qui vivit in aeternum creavit omnia simul.
By using this particular translation Augustine confirmed his belief that God created all things at the same moment.
Today, the Latin version of Sirach 18:1 remains unchanged.
According to the dictionary meaning of the Greek koinè, the verse in English should be:
He who lives forever created all things in common.
The translation of “koine” into “simul” continued. It entered into biblical usage when the Old Latin text of Sirach used by Augustine was incorporated into the Vulgate with the Greek adverb koine (in common) being translated into Latin as simul (simultaneously). At the time that nineteenth century Catholic theologians were turning to the second meaning attributed to “simul,” Protestant Charles Hodge of Princeton University was propagating it in his Systematic Theology to support his acceptance of long ages.
Fr. Vacant explained in his commentary on Vatican I how the meaning of simul as “in common” had been introduced by theologians of the day to justify reading the Lateran IV (and Vatican I) dogmatic texts to include long geological ages. The following text from Fr. Vacant’s commentary does not suggest that the Lateran IV definition of creation was ambiguous, or that there was any doubt that it would have precluded long ages and ipso facto evolution theory if simul had only one meaning. He simply explains that unless the meaning was changed from “all together” to “in common” long ages would have been excluded.
Others give it the meaning of “in common” or “equally.” It is this latter interpretation which is widely held today because it allows for long periods of time between the creation of the heavens and the earth and man. 
In view of the way that St. Augustine’s exegesis of Sirach 18:1 was used to reinterpret Lateran IV’s teaching on creation, it will be worthwhile to summarize the argument presented in this section. In the first place, St. Augustine was looking for biblical justification for his thesis of instant creation. Believing he had found what he was looking for, and not being a Greek scholar, he accepted koinè as meaning “at the same time.” Obviously, if he had realised that koinè correctly translated meant “in common,” he would not have used it to support his thesis of instantaneous creation. Although there is no hermeneutical connection between the Greek text of Sirach 18:1 and the original Latin text of the Lateran IV dogma, the translation of “koinè” in Sirach happened to be the same as the correct meaning of “simul” in Lateran IV. It was this apparent coincidence of meanings that in fact confirms the sense intended by the Lateran Council.
a) Genesis states that the world was created in six days.
b) The oldest Latin translation of Sirach 18:1 (the vetus Latina) states that all things were created “together” (simul). According to the Vetus Latina translation of koine used in St. Augustine’s day, Sirach states that all things were created together and not over six days. It was because of this apparent contradiction between the creation of all things “together” or “at the same time” (Sirach) and “in six days” (Genesis) that St. Augustine wrote the passage from The Literal Meaning of Genesis (given above) which shows clearly that the meaning he gives to simul is “all things together.” Had he wanted to extend the meaning of simul to “in common,” (koine) there would no longer have been a contradiction, and he would not have written the passage.
This first part of our argument shows that St. Augustine’s Latin text of Sirach 18:1 gave koinè in the underlying Greek text the same meaning as simul narrowly defined as “instantaneous.”
2. Lateran IV uses the word simul according to its medieval and current dictionary meaning, i.e. simul = “together” or “at the same time”—both of which denote simultaneity, as will be shown in more detail below. St. Augustine’s writings show that this is the very meaning he gave to simul in the fifth century.
3. In the 19th century, by referring to the translation of Sirach 18:1 used by St. Augustine, some theologians argued that because koinè had been translated as simul St. Augustine had meant to extend the meaning of the word simul (“all together”) to that of koinè (“in common”) thus stripping simul of any temporal significance. They deduced that Lateran IV could have used simul with this extended meaning.
However, St. Augustine never intended to extend the meaning of the word simul in this way. If he had, he would never have written the passage quoted above from The Literal Meaning of Genesis. Nor does the context of the Lateran IV statement on creation offer any reason to extend the meaning of the word in this manner. Therefore the 19th century reasoning is incorrect and the Lateran IV text should be understood with simul meaning “at once,” “together,” or “at the same time.”