Here is Pius XII proving existence of God by, among other things, proving a beginning in time:
D. THE BEGINNING IN TIME
35. First of all, to quote some figures-which aim at nothing else than to give an order of magnitude fixing the dawn of our universe, that is to say, to its beginning in time- science has at its disposal various means, each of which is more or less independent from the other, although all converge. We point them out briefly:
(1) recession of the spiral nebulae or galaxies:
36. The examination of various spiral nebulae, especially as carried out by Edwin W. Hubble at the Mount Wilson Observatory, has led to the significant conclusion, presented with all due reservations, that these distant systems of galaxies tend to move away from one another with such velocity that, in the space of 1,300 million years, the distance between such spiral nebulae is doubled. If we look back into the past at the time required for this process of the "expanding universe," it follows that, from one to ten billion years ago, the matter of the spiral nebulae was compressed into a relatively restricted space, at the time the cosmic processes had their beginning.
(2) The age of the solid crust of the earth:
37. To calculate the age of original radioactive substances, very approximate data are taken from the transformation of the isotope of uranium 238 into an isotope of lead (RaG), or of an isotope of uranium 235 into actinium D (AcD), and of the isotope of thorium 232 into thorium D (ThD). The mass of helium thereby formed can serve as a means of control. This leads to the conclusion that the average age of the oldest minerals is at the most five billion years.
(3) The age of meteorites:
38. The preceding method adopted to determine the age of meteorites has led to practically the same figure of five billion years. This is a result which acquires special importance by reason of the fact that the meteorites come from outside our earth and, apart from the terrestrial minerals are the only examples of celestial bodies which can be studied in scientific laboratories.
(4) The stability of the systems of double stars and starry masses:
39. The oscillations of gravitation between these systems, as also the attrition resulting from tides, again limit their stability within a period of from five to ten billion years. 40. Although these figures may seem astounding, nevertheless, even to the simplest of the faithful, they bring no new or different concept from the one they learned in the opening words of Genesis: "In the beginning . . .," that is to say; at the beginning of things in time. The figures We have quoted clothe these words in a concrete and almost mathematical expression, while from them there springs forth a new source of consolation for those who share the esteem of the Apostle for that divinely inspired Scripture which is always useful "for teaching, for reproving, for correcting, for instructing" (2 Tim., 3, 16).
And here he is, not attributing the figure five million years to scientist, but taking it in his own mouth, is a quote from his conclusions:
50. It has, besides, followed the course and the direction of cosmic developments, and, just as it was able to get a glimpse of the term toward which these developments were inexorably leading, so also has it pointed to their beginning in time some five billion years ago. Thus, with that concreteness which is characteristic of physical proofs, it has confirmed the contingency of the universe and also the well-founded deduction as to the epoch when the cosmos came forth from the hands of the Creator.
I said that the price was excessive. But he has proven a beginning in time and therefore the existence of God, right?
Well, he has NOT upheld Biblical inerrancy.
Creatorem Caeli et Terrae is indeed an article of the Faith, but so is Credo in Spiritum Sanctum ... qui locutus est per prophetas. And Moses, who wrote together Genesis, was a prophet.
A month and three days later he - Pius XII or Pacelli - was allowing a reader in Christmas litury to contradict this, since he was going to read:
Anno a creatione mundi, quando in principio Deus creavit caelum et terram, quinquies millesimo centesimo nonagesimo nono; a diluvio autem, anno bis millesimo nongentesimo quinquagesimo septimo; a nativitate Abrahae, anno bis millesimo quintodecimo; a Moyse et egressu populi Israel de Aegypto, anno millesimo quingentesimo decimo; ab unctione David in Regem, anno millesimo trigesimo secundo; Hebdomada sexagesima quinta, juxta Danielis prophetiam; Olympiade centesima nonagesima quarta; ab urbe Roma condita, anno septingentesimo quinquagesimo secundo; anno Imperii Octaviani Augusti quadragesimo secundo, toto Orbe in pace composito, sexta mundi aetate, Jesus Christus, aeternus Deus aeternique Patris Filius, mundum volens adventu suo piissimo consecrare, de Spiritu Sancto conceptus, novemque post conceptionem decursis mensibus (Hic vox elevatur, et omnes genua flectunt*), in Bethlehem Judae nascitur ex Maria Virgine factus Homo.
But if the Catholic Church has not decided which age of the Earth is correct before, wasn't he free to do so?
Vulgate would favour an age approximately around Ussher's date. Christ born 4004 anno Mundi. Roman Martyrology, based on Septuagint (at least in part) would give the Anno Mundi 5199 for Christ's birth in Bethlehem. It is very certain that the Church hasn't decided between these dates, since such a decision would imply a downgrading of either Vulgate or Roman Martyrology, and such a downgrading for either is hardly conceivable, it is also probable that the Church has not decided against the Byzantine, also LXX-based, chronology, in which Christ is born Anno Mundi 5508.
Couldn't he therefore decide for a scientific age instead?
No. The Biblical dates are approximate, but historical. The scientific ones are perhaps (or perhaps not) precise** but they are not historical. They are based on a kind of reasoning which is greatly attackable, once you start to ask the questions that Young Earth Creationists do ask.*** These sometimes have a beginning in time and claim to prove it, but far younger than the 5 billion years, but especially show faults in the dating methods for the older datings.
Hans Georg Lundahl
St Albert of Cologne
Here are the texts quoted:
THE PROOFS FOR THE EXISTENCE OF GOD IN THE LIGHT OF MODERN NATURAL SCIENCE
Address of Pope Pius XII to the Pontifical Academy of Sciences, November 22, 1951.
GREGORII XIII JUSSU EDITUM, URBANI VIII ET CLEMENTIS X AUCTORITATE RECOGNITUM AC DEINDE ANNO MDCCXLIX BENEDICTI XIV LABORE ET STUDIO AUCTUM ET CASTIGATUM
DECEMBER [Scroll down to 25.]
* The non bold text is red in original. The saying for liturgists is "do the red, say the black".
** It seems the "age of the earth" has shrunk from 5 to 4.5 billion years since the 50's!
*** See CMI articles - note: scientific, not theological! - Radiometric dating and the age of the Earth by Ralph W. Matthews, Ph.D. (presented like this on site: Dr Ralph Matthews has a Ph. D. in radiation chemistry and is a private scientific consultant. He was formerly a senior principal research scientist for the CSIRO, the major research organization of the Australian Government.) - The collapse of ‘geologic time’ (content presented as Tiny halos in coalified wood tell a story that demolishes ‘long age’.) by Steve Taylor, Andy McIntosh, and Tas Walker (presentations of latter two: Andy McIntosh, DSc., FIMA, C. Math., FInstE, C. Eng. FInstP. Andy earned his Ph.D. in combustion theory from the Cranfield Institute of Technology, Bedford, England, and a D.Sc. from the University of Wales. He was appointed a Fellow of the Institute of Energy (FInstE) with Chartered Engineer status (C.Eng), and became the Professor of Thermodynamics and Combustion Theory at the University of Leeds (NB: ‘professor’ in a British Commonwealth university is a title given only to the highest rank of lecturer). His research has included reducing supersonic drag of fighter planes, testing airflow through re-designed wind turbines, ignition studies of fluids and solids, pressure interactions with flames, and the movement of smoke and fire. This work involved a number of external companies and his research group has published many papers. He has also been appointed a Fellow of the Institute of Physics (FInstP). Andy is the author of Genesis for Today, a book that shows the relevance of Genesis for today's society. : Dr Tasman Bruce Walker Tas Walker has a Bachelor of Engineering with first class honours and a doctorate in mechanical engineering. He has been involved in the planning, design and operation of power stations for over 20 years with the electricity industry in Queensland, Australia. He has visited many coal mines in Queensland, for geological assessments of new fuel supplies for power stations. Tas also helped organise conferences including one of the Simulation Society of Australia One of his contributions has been to develop models for various aspects of the power industry such as the coordinated operation of the system and construction of power stations. In 1994, Dr Walker returned to university study, and completed a Bachelor of Science majoring in Earth Science, followed by First Class Honours in 1998. ...) Refuting Evolution—Chapter 8 How old is the earth? by Dr Jonathan D. Sarfati B.Sc. (Hons.), Ph.D., F.M. (... Dr Jonathan Sarfati was born in Ararat, Australia in 1964. He moved to New Zealand as a child and later studied science at Victoria University of Wellington. He obtained a B.Sc. (Hons.) in Chemistry with two physics papers substituted (nuclear and condensed matter physics). His Ph.D. in Chemistry was awarded for a thesis entitled ‘A Spectroscopic Study of some Chalcogenide Ring and Cage Molecules’. He has co-authored papers in mainstream scientific journals on high temperature superconductors and selenium-containing ring and cage-shaped molecules. He also had a co-authored paper on high-temperature superconductors published in Nature when he was 22. ...) Age of the earth 101 evidences for a young age of the earth and the universe by Don Batten (Don received both his B.Sc.Agr.(First Class Honours) and his Ph.D. from the University of Sydney. He worked for 20 years as a research horticulturalist with the NSW Department of Agriculture. His research included environmental adaptation of tropical/subtropical fruits such as mango, lychee and custard apple (Annona), floral biology, floral induction, breeding, environmental physiology (especially water requirements, effects of water deficits), plant taxonomy, and mineral nutrition. His research on floral induction of lychee and mango overturned long-held ideas which had been an impediment to the scientific understanding of these plants, as well as causing economic loss due to inappropriate management of these crops. He conducted a number of research projects that were externally funded, publishing his results in science journals. ... - probable the poster child for anti-Creationist quip that his published science is not creationist and his creationism ... well, that is their outlook).