To conclude this whole question of faith and its various branches, we have still to consider, Venerable Brethren, what the Modernists have to say about the development of the one and the other. First of all they lay down the general principle that in a living religion everything is subject to change, and must in fact be changed. In this way they pass to what is practically their principal doctrine, namely, evolution. To the laws of evolution everything is subject under penalty of death - dogma, Church, worship, the Books we revere as sacred, even faith itself.
Pope Saint Pius X - Pascendi Dominici Gregis.
I beseech thee, my son, look upon heaven and earth, and all that is in them: and consider that God made them out of nothing, and mankind also:
Second Book of Machabees, 7:28
But from the beginning of the creation, God made them male and female.
Holy Gospel according to St. Mark, 10:6
The Catholic Church does not read Holy Scripture in a purely literalist manner as do some people but we are taught that the literal, historic sense must be presupposed. We are also taught that wherever the Fathers of the Church were in unanimous agreement upon a certain interpretation of Holy Scripture, then that is the true and lawful understanding that we are obliged to believe. In 1564 the Council of Trent, one of the Church’s most important Ecumenical Councils and to which the Catholic conscience is bound forever, dogmatically taught that
Furthermore in order to restrain petulant spirits, It decrees, that no one, relying on his own skill, shall - in matters of faith, and of morals pertaining to the edification of Christian doctrine - wresting the Sacred Scripture to his own senses, presume to interpret the said Sacred Scripture contrary to that sense which Holy Mother Church - whose it is to judge of the true sense and interpretation of the Holy Scriptures - hath held and doth hold; or even contrary to the unanimous consent of the Fathers. 
This infallible teaching was restated by the First Vatican Council in 1870. Responding to the Modernist attack upon Holy Scripture His Holiness Pope St. Pius X issued his Praestantia Scripturae, 18 Nov. 1907:
Wherefore We find it necessary to declare and to expressly prescribe, and by this Our act we do declare and decree that all are bound in conscience to submit to the decisions of the Biblical Commission relating to doctrine, which have been given in the past and which shall be given in the future, in the same way as to the decrees of the Roman Congregations approved by the Pontiff; nor can all those escape the note of disobedience or temerity, and consequently of grave sin, who in speech or writing contradict such decisions, and this besides the scandal they give and the other reasons for which they may be responsible before God for other temerities and errors which generally go with such contradictions. 
The Biblical Commission of June 30, 1909, laid down very strict guidelines for Catholics to read and understand the first three chapters of Genesis.
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.
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.
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.
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.
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.
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.
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.
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. 
Theistic evolutionists often claim that paragraph IV allows them leeway for their belief in biological macroevolution because there was not a strict consensus of the Fathers in relation to the Creation period consisting of six, twenty four hour days. Whilst the overwhelming majority of the Fathers did believe in the distinction of six, natural days a minority of Fathers believed that the six days represented a certain space of time, or hierarchy, of instantaneous Creation as revealed to the angels. Theistic evolutionists are mistaken in this regard because none of the Fathers believed that the Creation period was of a duration any longer than six, natural days. The sought for consensus lay in that respect and constitutes the traditional belief of the Church throughout the ages; a belief proclaimed by Popes, Doctors, Scholastics and the humblest peasant.
Likewise, paragraph VIII is also claimed by theistic evolutionists to allow leeway for an unorthodox belief in billion year ages for the Earth, an absolutely necessary requirement for the evolutionary concept within the natural sciences. It is clearly the consensus of the Fathers that Creation took no longer than six, natural days and so the claim is without Patristic foundation and therefore invalid. Furthermore, Kolbe Center Advisory Council member Robert Sungenis, Ph.D, tells us that:
...the word "day" is used in Num 20:15, but it is the Hebrew plural YOMIM ("days"), followed by the quantitative adjective RABBIM, which means "many." In other words, the translation says "long time" because it IS a long time. It is "many days" in Hebrew. But that is not the word used in Genesis 1. Each reference to YOM in Genesis 1 is singular, referring to one day, with no adjectives.
As for the meaning of YOM in Genesis, the textual and grammatical evidence is quite overwhelming that it refers to one solar day of 24 hours. First, whenever YOM is used with an ordinal number in Scripture, it never refers to an indefinite or long period of time. In Genesis 1, there are six ordinal numbers enumerated: the first day...the second day...the third day...and so on to the sixth day. There is no instance in Hebrew grammar in which "day" preceded by an ordinal number is understood figuratively or as a long period of time. One of the most famous Hebrew grammars known to scholars, Gesenisus' Hebrew Grammar, elaborates on this point (Editor E. Kautzsch, second English edition, revised by A. E. Crowley, 1980, pp. 287-292; 432-437).
The most conclusive evidence that the word "day" in Genesis 1 is to be interpreted literally as a 24-hour period is confirmed by the consistent use of the phrase "and there was evening and morning," which appears in each of the days of Creation (cf., Genesis 1:5, 8, 13, 19, 23, 31). The use of "evening and morning" in Scripture shows that it always refers to the sequence of darkness and light comprising a single period of a day, a 24 hour period. Outside of Genesis, there are only eight appearances of "evening and morning" in Scripture (cf., Ex 16:8-13; 27:21; 29:39; Lv 24:3; Nm 9:21; Dan 8:26).
There are some cases in which the words "morning" or "evening" appear separately with the word "day," some of which refer to a literal solar day and some which are indefinite of time. But in Genesis, and the other aforementioned passages "evening and morning" are coupled together and are specified as one unit of time.
If the writer of Genesis intended to teach that YOM meant an indefinite period of time, such that he desired to convey long ages of process and change, he had numerous ways to convey such an idea. He could have used the plural YOMIM, as Mr. Young suggested of Num 20:15, or as Moses does in Genesis 1:14 ("let them be for days and for years") or Genesis 3:14 ("dust shall you eat all the days of your life"). But even then we must interject that, of the 702 uses of the plural YOMIM in the Old Testament, literal days are always in view.
As an alternative, the writer could have connected YOM with other Hebrew words of indefiniteness, such as DOR, OLAM, NETSACH, TAMID, or any of a dozen similar words and concepts in Hebrew. But the writer of Genesis 1 chose none of these possibilities; rather, he chose the most specific phrase for a 24-hour day that one can find in the Hebrew Scriptures. 
Although strictly speaking the Church has not issued a dogmatic statement specifically condemning the idea of biological macroevolution the entertaining of such an idea is implicitly ruled out by the Confession of Faith issued by Lateran Council IV in 1215. The text is often poorly translated in available references but Denzinger gives the Latin original that includes the adverb "simul" meaning "at once", "altogether", "at the same time".
Deus…creator omnium visibilium et invisibilium, spiritualium et corporalium: qui sua omnipotenti virtute simul ab initio temporis utramque de nihilo condidit creaturam, spiritualem et corporalem, angelicam videlicet et mundanam: ac deinde humanam, quasi communem ex spiritu et corpore constitutam.
God…creator of all visible and invisible things, of the spiritual and of the corporal; who by His own omnipotent power at once from the beginning of time created each creature from nothing, spiritual and corporal, namely, angelic and mundane, and finally the human, constituted as it were, alike of the spirit and the body. 
On the face of it Lateran IV's dogmatic Confession of Faith could appear to favor the minority position of complete, instantaneous Creation. But, in fact, the majority opinion fits very well with the definition. Those Fathers, such as St. Basil, who proclaimed six, twenty four hour days, due to the obvious sense of Holy Scripture, also believed in a single primordial Creation of elementary matter, whilst maintaining a realistic acknowledgement of the work of six days. They spoke of simultaneous Creation as being the Creation of formless matter to be shaped during the Creation period of six, natural days. 
The majority opinion is give further great weight by Holy Scripture where, in Exodus, God commands His people to keep the Sabbath holy because in six days He created the heavens, the earth and all they contain, and rested on the seventh day. The Catechism of the Council of Trent - also known as the the Roman Catechism - teaches that the seventh day of the week was made a day of rest because of this Divine Command.
We now come to the meaning of the word Sabbath. Sabbath is a Hebrew word which signifies cessation. To keep the Sabbath, therefore, means to cease from labor and to rest. In this sense the seventh day was called the Sabbath, because God, having finished the Creation of the world, rested on that day from all the work which He had done. Thus it is called by the Lord in Exodus. 
Thus Holy Scripture, the Catechism of the Council of Trent, along with the Patristics, Mediaevals and the entire Church inform us that the period of Creation ceased at the end of the sixth day, and so began the period of God's Providence. The counter-argument at this point usually formulates itself to imply that a new soul is created for each person at the moment of conception and so the creative process continues to this day. It is a poor argument that neglects to recognize that each soul shares the same nature as that given to Adam - complete with its later stain of guilt of Original Sin - and is not therefore the creation of a new nature but the continuation of an existing nature. Another poor counter-argument mistakenly confuses biological generation and genetic variation with the creation of new kinds. Vatican Council I in its Dogmatic Constitution of the Catholic Faith, Chapter 1, 4, spoke of providence thus:
Everything that God has brought into being He protects and governs by His providence, which reaches from one end of the earth to the other and orders all things well. All things are open and laid bare to his eyes, even those which will be brought about by the free activity of creatures. 
Vatican Council I opened on December 8th, 1869 and its Third Session, April 1870, concentrated exclusively on matters pertaining to Creation, Revelation, faith and reason. Why it should do so at this particular time in Church history becomes obvious when we consider that just eleven years previously, in 1859, Darwin's "On the Origin of Species" was first published. Eleven years later the macroevolutionary notion posited in the General Theory had made an enormous impression upon the rationalist, intellectual class of Europe. Already, in 1860, the Provincial Council of Cologne had decreed in no uncertain terms that:
Our first parents were formed immediately by God. Therefore we declare that the opinion of those who do not fear to assert that this human being, man, as regards his body, emerged finally from the spontaneous continuous change of imperfect nature to the more perfect, is clearly opposed to Sacred Scripture and to the Faith. 
Although a Provincial Council Decree does not in itself carry the weight of a de fide teaching it is most certainly Magisterial and was approved by the Church. The famous German theologian Matthias Scheeben, in his Dogmatica, Book III, condemned the idea of human evolution as being heretical. Rev. Fr. B. Harrison informs us that, following the example of the Council of Cologne, a dogmatic decree defining the Special Creation of the bodies of Adam and Eve was expected to be proclaimed by the First Vatican Council but unfortunately the Council had not reached that point when it was forced to close, unfinished. But the Vatican Council, reflecting and reminding the Church Militant of Lateran IV's dogmatic definition of Creation, did manage to state in its Dogmatic Constitution that:
This one true God, by His goodness and almighty power, not with the intention of increasing His happiness, nor indeed of obtaining happiness, but in order to manifest His perfection by the good things which He bestows on what He creates, by an absolutely free plan, together from the beginning of time brought into being from nothing the twofold created order, that is the spiritual and the bodily, the angelic and the earthly, and thereafter the human which is, in a way, common to both since it is composed of spirit and body. 
It's Canons contain the following:
On God the Creator of all Things: V. If anyone does not confess that the world and all things which are contained in it, both spiritual and material, were produced, according to their whole substance, out of nothing by God; or holds that God did not create by His will free from all necessity, but as necessarily as He necessarily loves Himself; or denies that the world was created for the glory of God: let him be anathema.
On Faith: IV. If anyone says that all miracles are impossible, and that therefore all reports of them, even those contained in Sacred Scripture, are to be set aside as fables or myths; or that miracles can never be known with certainty, nor can the Divine origin of the Christian religion be proved from them: let him be anathema.
On Faith: VI. If anyone says that the condition of the faithful and those who have not yet attained to the only true Faith is alike, so that Catholics may have a just cause for calling in doubt, by suspending their assent, the Faith which they have already received from the teaching of the Church, until they have completed a scientific demonstration of the credibility and truth of their faith: let him be anathema.
On Faith and Reason: I. If anyone says that in Divine Revelation there are contained no true mysteries properly so-called, but that all the dogmas of the Faith can be understood and demonstrated by properly trained reason from natural principles: let him be anathema.
On Faith and Reason: II. If anyone says that human studies are to be treated with such a degree of liberty that their assertions may be maintained as true even when they are opposed to Divine Revelation, and that they may not be forbidden by the Church: let him be anathema.
On Faith and Reason: III. If anyone says that it is possible that at some time, given the advancement of knowledge, a sense may be assigned to the dogmas propounded by the Church which is different from that which the Church has understood and understands: let him be anathema. 
The Canons of Session III finish with a stern and prophetic admonition:
But since it is not enough to avoid the contamination of heresy unless those errors are carefully shunned which approach it in greater or less degree, we warn all of their duty to observe the Constitutions and Decrees in which such wrong opinions, though not expressly mentioned in this document, have been banned and forbidden by this Holy See. 
It is claimed that if the Church did indeed oppose Darwin's notion as being dangerous to the Faith then the book would have been placed on the Index Librorum Prohibitorum. That it was not, apparently, placed on the Index was surely a mistake that has led to serious ramifications and confusion. The reason why it was not placed on the Index is currently a matter of debate and speculation. It is a subject to which serious research must be afforded. What is known with certainty is that, for whatever reason, many late nineteenth and twentieth century writers whose tracts were obviously dangerous to the Faith were not put on the Index. These included such figures as Marx, Freud, Hitler, so on and so forth. It appears that at this time there was such an explosion of theologically dangerous and immoral publications that the Congregation and its censors could not physically cope with the deluge. We do know for certain that Darwin's grandfather, Erasmus Darwin, who expressed, and is considered to be one of the originators of, evolutionary theory in his book Zoonomia (or The Laws of Organic Life), 1794, was placed on the Index in 1817. His work was extremely influential amongst the more "enlightened" souls of Europe and America and it is worth noting that he describes the Almighty in occult Masonic terms as "The Great Architect". Virtually all the biographers of Charles Darwin acknowledge the strong influence of Erasmus Darwin's scientific ideas upon his more celebrated grandson. We also know for certain that a number of Catholic authors influenced by Darwin's General Theory had their books placed on the Index and submitted to the Holy Inquisition, condemning and withdrawing their own works and erroneous opinions in this regard.
Rev. Fr. Brian Harrison, O.S., M.A., S.T.D, was given permission by the Congregation for the Doctrine of the Faith, formerly the Holy Office, to research documents held in its archives in regard to evolutionary theory at the end of the nineteenth century. It was found that books written by Catholics promoting the idea of biological evolution, particularly in regard to our first parents, were officially condemned and placed on the Index. Such condemnations are attached to the works of St. George Jackson Mivart, including his Genesis of Species (1871) and Lessons From Nature (1876); Rev. Fr. Caverni, De’ Nuovi Studi della Filosofia, Discorsi (1878); and the Rev. Fr. Leroy, O.P., L’évolution Restreinte aux Espèces Organiques, whose book was reported to the Supreme Congregation of the Holy Office as upholding the opinions of Darwin and placed on the Index in 1895.  The reaction of the authors whose work suffered condemnation is interesting to note. On the one hand, Rev. Fr. Leroy, Deo gratias, submitted his own will meekly to the perennial teaching of the Church. Besides withdrawing, as far as was in his power, his book from circulation the admirable Dominican priest had published a public retraction in the French newspaper, Le Monde, dated March 4th, 1895:
I have learned today that my thesis, which has been examined here in Rome by the competent authority, has been judged unacceptable, above all in what concerns the human body, since it is incompatible with both the texts of Sacred Scripture and the principles of sound philosophy.
A similar retraction was humbly offered by another Catholic author promoting Darwin's evolutionary biological hypothesis. J.A. Zahm, a Professor at the American Notre Dame University suffered his book Evolution and Dogma to be censured by the Holy Office. In a letter published in The Fortnightly Review, January 1900, p.37, he pleaded:
I have learned from unquestionable authority that the Holy See is adverse to the further distribution of Evolution and Dogma, and I therefore beg you to use all your influence to have the work withdrawn from sale.
Unfortunately, on the opposite side of the fence we have the sobering example of St. George Jackson Mivart. St. George Mivart, a distinguished Professor of Biology and a Catholic convert, had even been presented personally with his Doctorate in Philosophy from His Holiness, Pope Pius IX, in 1876. In a similar manner to the theistic evolutionists mentioned above, Mivart attempted to synthesize biological speculations concerning origins with Catholicism. Whilst opposing certain aspects of Darwin's theory he attempted to profess his own theory of evolution more in tune with the Faith. Nevertheless, his insistence upon macroevolutionary processes led him further and further into erroneous philosophical and theological problems. Book after book began to appear on the Index, including The Catholic Church and Biblical Criticism (1887); Catholicity and Reason (1887); Sins of Belief and Disbelief (1888); and Happiness in Hell (1892). Eventually, after severe admonition and having refused to sign three Professions of Faith at various times, Dr. Mivart was officially denied the Sacraments by His Eminence Cardinal Vaughan. St. George Jackson Mivart died, apparently unrepentant, in 1900 and was buried in unconsecrated ground without Ecclesiastical rites. On a more hopeful note, medical opinion was later presented showing that Dr. Mivart had been suffering from a debilitating illness for many years and this was claimed as the cause of his heretical behavior and disobedience, rather than his own will. Under such circumstances of doubt St. George Jackson Mivart were finally placed in hallowed ground four years after leaving this vale of tears. 
The reign of His Holiness, Pope Saint Pius X witnessed the Church's most stringent defence yet against the increasing web of Modernist intrigue and venom. To begin with Modernism directed its attack primarily upon the traditional understanding of Sacred Scripture. The consequence of such an attack was to weaken Scriptural belief for Catholic dogma and doctrine. One of those strongly suspected of Modernism was Rev. Fr. Marie Joseph Lagrange, O.P., founder of the École Biblique et Archéologique Française de Jérusalem.
In an attempt to synthesize the Faith with the unproven ideas of modern science Rev. Fr. Lagrange introduced and successfully promoted three conceptual novelties into Scriptural exegesis - Legendary Primitive History; Historical Appearances; and Literary Genres. Kolbe Center advisor Dr. Dominique Tassot reminds us that:
It is obvious that an intelligent use of these three methods is sufficient to get rid of any difficult passage of the Bible. But the authority of the Sacred Writings disappears at the same time, divine inspiration and inerrancy being inseparable! 
By using such novel and erroneous tools of exegesis Rev. Fr. Lagrange soon wrote a Commentary Upon Genesis. As with the works of Rev. Fr's. Leroy, Dorlodot, Bishop Bonomelli of Cremona et al, this document was condemned by the Church and the Dominican priest forbidden to publish it. Whilst many wayward souls pursuing the methods of historicism resisted our Blessed Lord in His Church and suffered excommunication or public apostasy, Rev. Fr. Lagrange apparently possessed the necessary humility and obedience to remain in the Church. His letters to the Holy Father expressed the following sentiments:
Most Holy Father, prostrate at the feet of Your Holiness, I accept with the most filial obedience your decision, communicated to me through the master general of our order, forbidding me to publish, in any way whatsoever, a commentary on Genesis.
But it is not enough to obey Your Holiness’ orders. I have therefore resolved to consider even your wishes as orders. If then Your Holiness deems it is preferable that I cease on biblical studies, I will give them up immediately without any hesitation. I am not the type to submit and then continue.
I only beseech Your Holiness to deign to believe in the right intention that has inspired me up to now. The measure Your Holiness has taken in my regard makes me fear I have been mistaken, and it would be impossible for me to write the slightest line with the awareness that I am disobeying the instructions of Your Holiness. 
His Holiness Pope Leo XIII had previously identified the insidious current of Historicism and duly warned the Church in Providentissimus Deus:
All the books which the Church received as sacred and canonical were written wholly and entirely, with all their parts, at the dictation of the Holy Ghost. It is impossible, therefore, that any error can co-exist with divine inspiration. For not only is divine inspiration per se incompatible with error, but also it excludes and rejects error absolutely and necessarily because it is impossible that God Himself, the Supreme Truth, can utter that which is not truth.... Hence, because the Holy Ghost employed men as His instruments to write the sacred books, we cannot say that it was these inspired men who eventually have fallen into error, without saying that the primary Author also erred. For, by supernatural power, He moved and impelled them to write. He Himself assisted them during the writing in such a way that everything which He ordered them to write, they rightly understood, faithfully willed to write down, and finally, aptly expressed in words with infallible truth. Otherwise, it could not be said that God was the Author of the entire Scripture. 
Notwithstanding the condemnations, admonitions and censures of the Church during this period, Historicism, and the Modernism that it spawned, continued to diffuse its deadly pathology. Even after the Pontifical Biblical Commission had issued its guidelines on interpreting Holy Scripture, backed up by Praestantia Scripturae, the problem persisted. So much so that His Holiness Pope Pius XII was forced to mirror the words of the Saintly Pontiff quoted at the beginning of this essay. In a speech to the International Congress of Historical Sciences, September 7th, 1955 he stated that:
The term 'historicism' indicates a philosophical system that acknowledges change and evolution in the whole spiritual reality, in the understanding of the truth, in religion, and in morality. As a consequence, it rejects everything that is permanent, eternally valid, and absolute. Such a system is certainly irreconcilable with the Catholic conception of the world. 
Humani Generis, published in 1950, was the last Magisterial statement concerning origins. In that encyclical His Holiness Pope Pius XII reaffirmed condemnation of Pantheistic and Gnostic conceptions of evolutionism and also the heretical idea of polygenism - the notion of more than one first parent, of more than one human individual whom we all descend from. Such doctrine not only destroys the heretical speculations of theologians such as Fr.'s Teilhard de Chardin and Rahner but also stops the naturalistic conceptual process of macroevolution dead in its tracks. A Monitum was issued by the Holy Office in 1962 warning against the works of Rev. Fr. Pierre Teilhard de Chardin, S.J. The Monitum is still in force and was, in fact, reiterated in 1981.  Humani Generis spends much effort warning the Church Militant of false philosophy and false science being used to undermine Sacred Scripture and Tradition but unfortunately one paragraph leaves a chink of light for theistic evolutionists to work upon. His Holiness wrote:
For these reasons the Teaching Authority of the Church does not forbid that, in conformity with the present state of human sciences and sacred theology, research and discussions, on the part of men experienced in both fields, take place with regard to the doctrine of evolution, in as far as it inquires into the origin of the human body as coming from pre-existent and living matter -- for the Catholic Faith obliges us to hold that souls are immediately created by God. However this must be done in such a way that the reasons for both opinions, that is, those favorable and those unfavorable to evolution, be weighed and judged with the necessary seriousness, moderation and measure, and provided that all are prepared to submit to the judgment of the Church, to whom Christ has given the mission of interpreting authentically the Sacred Scriptures and of defending the Dogmas of Faith. Some however rashly transgress this liberty of discussion, when they act as if the origin of the human body from preexisting and living matter were already completely certain and proved by the facts which have been discovered up to now and by reasoning on those facts, and as if there were nothing in the sources of divine revelation which demands the greatest moderation and caution in this question. 
Blatantly disregarding the weight of dogma, doctrine and tradition previously outlined in this essay, theistic evolutionists endeavor to argue from this one paragraph that it leaves open the possibility that the Special Creation of Adam refers only to his soul and not to his body. Yet in order to do so the theistic evolutionist must also ignore the consistent teaching of the Church concerning Adam and Eve. For instance, His Holiness Pope Pelagius writing to King Childebert I in 557 A.D:
For I confess that all men from Adam, even to the consummation of the world, having been born and having died with Adam himself and his wife, who were not born of other parents, but were created, the one from the earth, the other [al.: altera], however, from the rib of man. 
The affirmation of His Holiness Pope Pelagius is part of a Profession of Faith, Fides Pelagii Papae, made by a successor of St. Peter in his role as Supreme Pontiff of the Universal Church. The Profession of Faith made to King Childebert I was shortly afterwards repeated by His Holiness to the whole Church in Vas Electionis. Vas Electionis also carries an affirmation of Faith regarding the Universal Judgment in which His Holiness solemnly professes that:
I confess ... that all men from Adam onward who have been born and have died up to the end of the world will then rise again and stand "before the judgment-seat of Christ," together with Adam himself and his wife, who were not born of other parents, but were created: one from the earth and the other from the side of the man....(Denzinger 443, editions after 1965).
Or His Holiness Pope Leo XIII, Arcane Divinae Sapientiae, 1880:
We record what is to all known, and cannot be doubted by any, that God, on the sixth day of Creation, having made man from the slime of the Earth, and having breathed into his face the breath of life, gave him a companion, whom He miraculously took from the side of Adam when he was locked in sleep. God thus, in His most far-reaching foresight, decreed that this husband and wife should be the natural beginning of the human race, from whom it might be propagated, and preserved by an unfailing fruitfulness throughout all futurity of time. 
Following this line of erroneous reasoning, and disregard of the Magisterium, such people claim that Adam was originally a brute ape-like ancestor specially chosen by God to receive a soul, thereby choosing to separate himself from his previous animal kith and kin. With the Special Creation of Eve from Adam's side (should they believe such a thing) a scientifically unknown process of mutation and natural selection made men what we are today and apes what they are. Such a concept is theologically, philosophically and biologically absurd.
Knowing what the Church has consistently taught on such matters, the question remains as to why His Holiness Pope Pius XII would allow calm and balanced discussion between experts in theology and the natural sciences regarding evolution. The answer may be found by considering the paragraph in question not in isolation, as many have done, but in its proper context. A footnote within the paragraph refers to his Allocution to the members of the Pontifical Academy of Sciences, November 30th, 1941, in which he affirmed that:
The numerous research works in the fields of paleontology, of biology as well as in morphology, on other problems concerning the origins of man have, to date, come up with nothing positively clear and certain. It behooves us, therefore, to leave to the future the answer to this question, if, perchance, science, enlightened and guided by Divine Revelation, is able to provide certain and definitive results (answers) on such an important question. 
In earlier paragraphs of Humani Generis we read that:
Now Catholic theologians and philosophers, whose grave duty it is to defend natural and supernatural truth and instill it in the hearts of men, cannot afford to ignore or neglect these more or less erroneous opinions. Rather they must come to understand these same theories well, both because diseases are not properly treated unless they are rightly diagnosed, and because sometimes even in these false theories a certain amount of truth is contained, and, finally, because these theories provoke more subtle discussion and evaluation of philosophical and theological truths.
If philosophers and theologians strive only to derive such profit from the careful examination of these doctrines, there would be no reason for any intervention by the Teaching Authority of the Church. However, although We know that Catholic teachers generally avoid these errors, it is apparent, however, that some today, as in apostolic times, desirous of novelty, and fearing to be considered ignorant of recent scientific findings, try to withdraw themselves from the sacred Teaching Authority and are accordingly in danger of gradually departing from revealed truth and of drawing others along with them into error. 
It would appear that on the one hand His Holiness wished to see the erroneous opinions presented by rationalist scientists defeated due to the application of new knowledge and true science - science that can not be at variance with the Faith - whilst at the same time wanting theologians to understand and follow the scientific debate in order to be better able to combat heresy within the Church. Catholics were supposed to have been presented with sound doctrine to prevent them from falling for the siren song of rationalism. That the theologians and many Catholic scientists themselves fell into the rationalist trap, and that Catholic scientists loyal to the Magisterium have generally been ignored, has meant that up until the present time no conclusion to this drawn out saga has been forthcoming. The situation was already such in 1950 that His Eminence Ernesto Cardinal Ruffini complained that:
Through several Catholic circles there has spread the impression that the question of man's origin has recently received such encouraging results from paleo-anthropological research, that we are now obliged, for the sake of truth as well as of prudence, to cast aside our previous convictions based on the Bible, the doctrine of the Fathers of the Church, as well as the constant teaching of the Church. 
His Eminence knew the errors and stratagems of Modernism well, and watched in dismay as he witnessed it advance through the decades. He had published, during the 1940's, a strong defense of the Catholic understanding of Creation and early history, and the current attack upon it, in a book entitled The Theory of Evolution Judged by Reason and Faith.
To these authorities - Holy Scripture, the Holy Fathers, major and minor theologians - we must add the Christian sense (sensus fidelium, the faithful echo of the Church's teaching), so universal on this question and so certain that almost no member of the faithful would be free from surprise and scandal if he heard the teaching that Adam was born of beasts, that the blood in his veins was the blood of animals, that the human race, as regards the flesh, is related to the brute beasts. 
If it is true that the body of woman was formed directly by God and thus does not come by way of evolution, who will be persuaded that man's body comes from the brute beast? What an absurdity! . . . If we wish to stand by Holy Scripture we must accept it in its entirety. . . . She gets the name Virago (ishah: woman) because she is taken from the vir (ish: man); likewise the man is called Adam (=homo) because, as Genesis says, he is taken from the adamah (=humus). Whenever Holy Scripture speaks of the origin of the human body, it always names the earth and only the earth. 
The situation regarding the Church's position towards evolution since the publication of Humani Generis has remained one of confusion as far as many of Her human elements have been concerned. The letter addressed to the Pontifical Academy of Science, in 1996, on behalf of His Holiness John Paul II is oft quoted by theistic evolution propagandists to "prove" that Catholics are free to believe in biological macroevolution. In a similar vein the book, In the Beginning: A Catholic Understanding of the Story of Creation and the Fall, written by, as he was then, His Eminence Cardinal Ratzinger is claimed to show the position of the Church concerning this matter. Likewise, the 2004 document from the International Theological Commission, entitled Communion and Stewardship, is often appealed to. That none of these documents are Magisterial, just private opinions, does not seem to matter in the quest to evolve. The PAS letter, whilst approved and presented on behalf of a reigning Pontiff, did not say anything new concerning evolution in regard to faith and morals. It is also interesting to note that, apparently, the letter was written on behalf of His Holiness by a member of the PAS, a secular orientated advisory body that has absolutely no Magisterial Authority within the Church. Knowing such information should help us to understand why obvious mistakes appear in the address. For example, the letter claimed in paragraph four that:
Taking into account the scientific research of the era, and also the proper requirements of theology, the encyclical Humani Generis treated the doctrine of "evolutionism" as a serious hypothesis, worthy of investigation and serious study, alongside the opposite hypothesis. 
Humani Generis, in fact, did no such thing. In Humani Generis His Holiness Pope Pius XII reaffirmed the Church's condemnation of evolutionism. It was biological evolution that he allowed investigation into and furthermore His Holiness indicated in the encyclical, and other addresses, that rather than being a serious hypothesis such "conjectural opinions" must be treated with "caution". Evolutionism is a philosophical view that denies the existence of any immutable essence and such ideas have always been condemned by the Church - the Syllabus of Errors of His Holiness Pope Pius IX, 1864, and that of His Holiness Pope St. Pius X, Lamentabili Sane, 1907, for example.  
In conclusion, the attempted rewriting of Sacred Scripture was by no means confined to Genesis but applied to much of Holy Writ. Even so, it certainly appears that Genesis bore, and still bears, the brunt of the Modernist attack on the Holy Bible. One favorite target of theistic evolutionists is Noah's Flood. The fact that Our Blessed Lord, Himself, and Saint Peter, Prince of the Apostles, both referred to the Deluge in connection with the Second Coming holds little weight with those infected by Modernist indoctrination. Ignoring the obvious fact of huge, sudden, sedimentary deposition all over the world, and the fossilized record of sudden death contained within it, the preposterous claim is made that the Deluge was a local flood somewhere in the region of the Black Sea. Yet, we read in the Bull, Unam Sanctum, of His Holiness Pope Boniface VIII, 1302, that:
There had been at the time of the deluge only one ark of Noah, prefiguring the one Church, which ark, having been finished to a single cubit, had only one pilot and guide, i.e., Noah, and we read that, outside of this ark, all that subsisted on the earth was destroyed. 
This partial summary of the historic battle conducted by the Church against evolutionary ideas may perhaps serve, by the grace of God, as a wake-up call to some of the faithful. But let the words of St. Peter, the rock upon whom the Church is built, and Christ the King Whom we serve, act as a warning to those precious, but wayward, souls who claim to be Roman Catholic but act as though they are infidel:
3 Knowing this first, that in the last days there shall come deceitful scoffers, walking after their own lusts,
4 Saying: Where is his promise or his coming? For since the time that the Fathers slept, all things continue as they were from the beginning of the Creation.
5 For this they are wilfully ignorant of, that the heavens were before, and the earth out of water, and through water, consisting by the word of God,
6 Whereby the world that then was, being overflowed with water, perished.
7 But the heavens and the earth which are now, by the same word are kept in store, reserved unto fire against the day of judgement and perdition of the ungodly men.
Second Epistle of St. Peter the Apostle, Chapter 3.
35 Heaven and earth shall pass, but my words shall not pass.
36 But of that day and hour no one knoweth, no not the angels of heaven, but the Father alone.
37 And as in the days of Noe, so shall also the coming of the Son of man be.
38 For as in the days before the Flood, they were eating and drinking, marrying and giving in marriage, even till that day in which Noe entered into the ark,
39 And they knew not till the Flood came, and took them all away; so also shall the coming of the Son of man be.
The Holy Gospel of Jesus Christ, according to St. Matthew.
Notes and References.
1). Council of Trent, Session IV. April 8th, 1564. history.hanover.edu/texts/trent/ct04.html