Religious and philosophical inputs to geochronology
David J. Tyler
The Legacy of the Greeks
Aquinas' synthesis of Aristotelian philosophy and Catholic theology
Galileo and the "Two Books"
Early science and the adoption of Baconian principles
Geology and the "Two Books"
In geological circles, it is now unquestioned that the Earth has had a history measured in billions of years. But how do we know this? One geologist known to the writer said in conversation that the age of the Earth is a question answered by physics - he was referring to radiometric dating and he speaks for many. Historically, geological timescales were not "determined by physics", but by the adoption of certain methodological principles of interpretation of geologic data. This paper attempts to trace some of the critical intellectual changes that were involved in the acceptance of long geological ages, showing that the changes had more to do with philosophical presuppositions rather than "objective" science. The question as to whether present day techniques for dating the Earth and its rocks are similarly affected by presuppositions lies outside the scope of this paper, but it is suggested that the issues discussed here are a foundation for providing an answer.
A further consideration to justify the themes addressed has been the tendency of some creationist writers on the history of science to present an unbalanced perspective on trends in 19th century geology. The issue has sometimes been presented as a controversy between uniformitarianism (championed by Charles Lyell) and catastrophism (used as a synonym for Flood Geology). The problem is that the majority of catastrophists in the 19th century already accepted long geological ages! Flood Geology was generally considered by catastrophists to be responsible for just the Diluvium (recognised later in that century as glacial deposits). If we want to find out what factors were responsible for the acceptance of extended geological time, we must look earlier than the 19th century!
The history of scientific thought demonstrates very clearly the important influence of dominant worldviews. The ancient Greeks were impressive philosophers, mathematicians and astronomers. However, they failed to provide a foundation for scientific study because they were too disposed to be deductive thinkers: their world-view affected the way they approached the data before them.
Nevertheless, the strengths of their philosophical, mathematical and astronomical work meant that their influence continued long after the flowering of Greek culture.
During the Middle Ages, people began to realise that their Church-based scholarship was languishing and a new impetus was needed. Then they rediscovered the Greeks. Aristotelian philosophy soon made an extraordinary impact. His writings were considered to surpass those of the others in terms of depth and diversity of interests. People read Aristotle on physics, metaphysics, logic, cosmology, the elements, epistemology and the nature of change. He extended their minds; he excited their imagination.
Significantly, these years saw the emergence of the universities as centres of intellectual activity. The staff of these institutions did not perceive themselves as being just a different kind of seminary - rather, they had their own independent identity. It was accepted that theology had to be the most important faculty, but the theologians were not allowed to control every other faculty. The writings of Aristotle gripped these scholars: there had been an intellectual vacuum in most disciplines which nothing else seemed to fill. As a result, Aristotelianism became the entrenched orthodoxy in universities from 1200 until the middle of the 17th century.
There was no question that Aristotle was a pagan Greek philosopher and that his approach was in tension with that of the Church scholars. This situation had to be addressed. It came to a head first in the University of Paris, where some theologians and nearly all the arts masters became Aristotelians.
This made the more traditional theologians (who were the majority) very uneasy. The result was a ban on Aristotle's books relating to natural phenomena in 1210 and 1215, and an attempt to expurgate them in 1231. Despite rearguard efforts like this, Aristotle became, in time, to be the core of the curriculum, leaving a large number of traditionally-minded theologians convinced that things were being taught subversive to the faith (Grant, 1986).
Thomas Aquinas (1225-1274) had the confidence of the traditionalists and yet he saw Aristotle as the greatest of human philosophers: someone achieving the highest level of human thought without the aid of revelation. Aquinas proposed a way of incorporating the essence of Aristotle into the Christian intellectual tradition. He did it by arguing that the world of nature could be known separately from the world of the spirit. The sacred could be distinguished from the secular. Using more contemporary terminology, Aquinas compartmentalised knowledge.
This, in my view, was an approach to knowledge which has been extraordinarily influential within the Catholic tradition and outside it. Many intellectual leaders have adopted the same strategy of organising knowledge in compartments which do not communicate. It has been called the "double revelation" approach: "God reveals himself separately in the natural world and in the spiritual world". It is also known as the "two books" approach: "There is a book of nature which can be read separately from the book of the Spirit. These books belong to two distinct domains of knowledge and are largely independent of each other".
It must be said that Aquinas' synthesis was not accepted immediately. Many traditional theologians continued to speak about the subversive character of Aristotelianism. However, these voices faded with time, and Aristotelian philosophy became the orthodoxy for all secular studies.
Although not presented in the same context, Schaeffer's books Escape from reason (1986) and The God who is there (1986) have drawn attention to Aquinas' legacy to succeeding generations in philosophy and many other disciplines of knowledge. He refers to "the teaching of a man who changed the world in a very real way". The basic arguments of this paper relating to the compartmentalisation of knowledge were stimulated by Schaeffer's analysis of the history of ideas.
The double revelation theory was brought into action when Copernican astronomy became the focus of attention. The problem was not simply that the Bible appeared to teach geocentrism; the more fundamental conflict was that the academic world was wedded to Aristotelian philosophy which was committed to geocentrism as a matter of logical necessity. Those who employed the "two books" argument to defend Copernicanism were keen to emphasise the autonomy of science and quick to complain about people meddling in matters where they had no expertise. Thus Galileo wrote:
"Our opinion is that the Scriptures accord perfectly with demonstrated physical
truth. But let those theologians who are not astronomers guard against rendering
the Scriptures false by trying to interpret against it propositions which
might be true and might be proved so" (quoted in Westman, 1986, p.101).
"I think that in discussing natural problems we should not begin from the
authority of scriptural passages, but from sensory experiences and necessary
demonstrations; for Holy Scripture and nature proceed alike from the divine
Word, the former at the dictate of the Holy Spirit and the latter as the
faithful executrix of God's commands. Furthermore, Scripture, adapting itself
to the understanding of the common man, is wont to say many things that
appear to differ from absolute truth as far as the bare meaning of the words
is concerned. Nature, on the contrary, is inexorable and immutable; she
never transcends the limits of the laws imposed upon her, and she is indifferent
whether her secret reasons and ways of operating are understood by men.
It would seem, therefore, that nothing physical that sense experience sets
before our eyes, or that necessary demonstrations prove to us, should be
called in question, not to say condemned, because of biblical passages that
have an apparently different meaning. Scriptural statements are not bound
by rules as strict as natural events, and God is not less excellently revealed
in these events than in the sacred propositions of the Bible" (quoted in
Shea, 1986, p.126).
It took the Reformation to break down man's pride in his own abilities, to promote a spirit of seeking after truth as an expression of worship; and to motivate men in the use of this knowledge to "subdue the earth" in obedience to God's command. The relationship between spiritual and natural knowledge was a secondary issue during the Reformation, and there are indications that traditional Christian thinking in this area was inadequately reformed. The idea that God has revealed himself in the Book of Nature and the Book of Scripture was popularly held by Protestants.
The influential Francis Bacon incorporated the "two books" into his philosophy: which is widely regarded as having supported and stimulated the rise of genuine science. Certainly, it provided inspiration for the founders of the Royal Society in England and gave a boost to scientific work in many European countries. However, the cautionary words of Prior (1954) are much needed.
"There is an obvious similarity between Bacon's notions about the deadly
sin and cardinal virtue in science and the moral ideals of man in the Christian
tradition. But the distinction between the ethical virtues and vices of
a scientist is not insisted upon in Bacon because it is essentially religious
and Christian. Christianity may be the source, but it is not the sanction.
The grounds of Bacon's analysis are naturalistic and humanistic, and he
derives them out of the aims of true learning and the demands of good method.
It is a question of success and failure in the discovery of useful knowledge."
"Bacon separated completely the realms of religion and of natural knowledge
in the interest of establishing a science free of superstition and presumably
a religion free of sophistry. The basis of religion was for him the knowledge
of God's will and law, matters which lay beyond man and hence were knowable
only through divine revelation. Bacon urged therefore "that we do not presume
by the contemplation of nature to attain to the mysteries of God", that
the pursuit of natural knowledge be kept clear of religion, and that men
"do not unwisely mingle or confound these learnings together".
The same basic approach supported the development of Natural Theology in the 17th and 18th Centuries. Schaeffer sees this trend as a legacy from Aquinas: a consequence of his dividing knowledge into two autonomous realms. Writing in Escape from reason (1986), he says:
"One result . . . was the development of natural theology. In this view,
natural theology is a theology that could be pursued independently from
the Scriptures." (page 11)
The Baconian influence was significant for geology. The testimony of Humphrey Davy in 1805 is worthy of note. (Davy not only made important discoveries in chemistry, he also was a popular lecturer on many themes - including geology).
"Many scientific persons before Bacon had pursued the method of experiment
in all its precision: many had dared to despise the logic and forms of the
ancients. But he was the first philosopher who laid down plans for extending
knowledge of universal application.... The pursuit of the new method of
investigation in a very short time wholly altered the face of every department
of natural knowledge; but this influence was in no case more distinct than
in the advances of geology and chemistry ..." (Ospovat, 1978, p.28).
"One could hardly exaggerate the standing and influence of Bacon, both on
Western science and on the thinking of Bible-believing Christians in their
attitude to it ... Other early members of the Royal Society tended to see
themselves as Baconians, and his approach was standard to scientist Christians
in the seventeenth and eighteenth centuries. In fact, mainstream scientist
Christians in Western Europe for well into the nineteenth century (if not
later) saw themselves as following the traditions of Bacon, Descartes or
This general interpretation of intellectual trends can now be applied specifically to the development of geological thought. Two strands of understanding need to be identified: the recognition that the rocks forming the Earth's crust contain a geological history, and the association of geologic processes with certain timescales.
The science of geology did not progress under the Greeks, although considerable expertise developed in pre-scientific times related to the mining of useful materials such as metallic ores. Early geological thinking was stimulated and heavily influenced by biblical history. Humphrey Davy was a very popular lecturer in matters of science at the beginning of the nineteenth century, and the text of his 1805 lectures in geology (Ospovat, 1978) provide a useful outline of the various "systems" of geology that had been proposed up to that time. In what follows, Davy is not followed in every detail, but he does provide the framework for analysis.
Thomas Burnet's Sacred History of the Earth appeared in 1681. In this work, biblical history provides the context for the key events of geological history. Although Davy considered the book to be of low quality and "wholly unworthy of attention", Rudwick (1986) sees more substance in Burnet's writings and states that the book was "the prototype of a new kind of writing that became known as the "theory of the Earth"" (p.305). Contrast this with Davy, who said that it was Leibnitz who first "attempted a general system of geology". Leibnitz published his ideas in Protogea (1693) and discussed "the primary creation, the deluge, the changes that have been since produced and that will be produced in future ages. He assumes as the foundation of his reasoning the account of the creation given in the sacred writings ..." (Davy, p.30). Whiston is mentioned as someone who worked through in much more detail an idea that was considered in Protogea(that the Deluge was initiated by cometary impact). Whiston's A new theory of the Earth was published in 1696. Not discussed by Davy, but worthy of inclusion in this summary of theorists, is John Woodward who published his Essay towards a natural history of the Earth in 1695. His thesis was that the whole series of rock strata had its origins in the Noahic Flood, where the sequence of rock types and their enclosed fossils was determined by the specific gravity of the various solids. His posthumous publications on fossils have been regarded generally as an important contribution to early palaeontological science.
Summarising this period, most of the pioneering work in geology was set in a Flood Geology context. Burnett's influential Sacred History of the Earth used the scenario of Creation/Fall/Flood to explain the features of the Earth observed today. Other studies of sedimentation and the significance of fossils were provided by writers who respected biblical history. Their various contributions did advance geological understanding - bearing in mind that these men must be assessed according to the state of knowledge at that time, and recognising that none of them had a coherent Christian methodology for their academic work. For these scholars, timescales were short because geologic processes associated with a global flood must be necessarily catastrophic.
The next key theorist was Buffon, who published Histoire et thèorie de la terre in 1749 and Èpoques de la nature in 1779. This man broke with short timescales completely and proposed that the Earth was produced initially by a comet impacting on the sun.
"And he imagines three different epochs in the history of the cooling of
the surface before marine animals existed, and five epochs before it was
fitted for the residence of land animals and of man" (Davy, p.32).
Finally, Davy turns to the plutonist/neptunist controversy which was a live issue in his own day. James Hutton championed the plutonist cause but, more importantly for this analysis, broke completely with referencing Scriptural history. This was because he was a philosophical empiricist (Tyler, 1989). He suggested that the geological processes operating today, together with the passing of sufficient time, provide adequate causes for all the geological features observable on Earth. Davy says: "Few works have ever excited more attention; few works have ever been more warmly admired, or more vehemently attacked ..." (p.47). The neptunist flag was held by Abraham Werner, who considered that "all the existing substances composing the globe were in a state of solution by the aqueous fluid... The rocks that are called primordial or primitive and that contain no organic remains, he supposes [to be] the first to have been deposited from the original aqueous solution... " (Davy, p.48). These materials were subsequently disaggregated and redeposited to for a sequence of transitional rocks, after which the earth was inhabited by plants and animals. During this period, the secondary strata were laid down, whereby solid particles came out of suspension in the oceans and covered the organic remains to preserve them as fossils. The details and outcome of this particular controversy has often been discussed (Hallam, 1983; Goodman and Russell, 1991) and will not be considered further here.
Summarising these developments in the eighteenth century, the "two books" approach was becoming dominant and geology became increasingly divorced from biblical revelation. According to Moore (1968) "... the Baconian compromise became a convention in English-speaking scholarship for more than two hundred years: the basis for congenial relations between naturalists and exegetes ..." (p.323). The Enlightenment brought the impact of empiricist philosophy to the scholarly world, together with a conscious rejection of revelation as a foundation for knowledge. James Hutton is spoken of as the "Father of Geology" primarily because he was the first to articulate systematically this new worldview.
However, it should be recognised that, for all the advocates of the various systems, it was not the data of geology that led to the acceptance of long timescales, but the philosophical presuppositions of the scholar which governed the interpretation placed on that data.
Some geologists still recognised catastrophic processes at work in the rock record and developed geological histories punctuated by catastrophes. However, Biblical history was rarely, if ever, mentioned in their writings. The 19th century "catastrophists" held to a multiple catastrophe model of Earth history, of which the Genesis Flood was the most recent (leaving relatively insignificant surficial deposits referred to as the "Diluvium"). These held their own against the new "Uniformitarians" represented by Hutton, until Charles Lyell captured the minds of the geologic community by insisting that Hutton's methodology was the only permissible scientific approach to the study of the Earth. The Lyellian paradigm has reigned over geological thinking for over 150 years, and is only now being dismantled.
Flood geologists have responded to these developments in different ways, but usually from positions of weakness because opportunities for Diluvialists to develop a career and participate in the academic world have been few. A deficiency apparent in their 19th and 20th century apologetic position has been a general neglect of the evidences for a geological history recorded in the rocks - something which a greater awareness of the geological debates in the 18th and 19th centuries would help to remedy. Evidences for catastrophism have been presented by contemporary diluvialists which have led to claims that the fossiliferous rocks as a whole were formed during the Flood year. Whilst this has convinced some, many others have felt that this scenario does not do justice to the evidences for a more sophisticated picture of successive geologic events.
From these historical perspectives, it is concluded:
(a) that Flood geology models must be sought which do justice to the evidences for a significant geologic history;
(b) that most of the arguments for long timescales are paradigm-driven rather than scientific;
(c) that a thoroughly Christian worldview is crucial to the development of a more reliable understanding of geologic evidences, and this will require the abandonment of the "double revelation" approach to knowledge.
It is suggested that whilst conclusions (a) and (b) are of direct relevance to Bible-believing students of geology, conclusion (c) is relevant to all Christians concerned about the scientific enterprise. What is to be made of statements like this from Marston and Forster (1989)?
"We would, then, defend the classical Baconian approach, which was rooted
in earlier Christian ideas and has shaped the whole of Christian and scientific
thinking on relationships of science and theology" (p.268).
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Hallam, A. 1983. Great geological controversies. Oxford: Oxford University Press.
Marston, P.V. and Forster, R. 1989. Reason and Faith. Eastbourne: Monarch.
Moore, J.R. 1986. Geologists and interpreters of Genesis in the nineteenth century. In: Lindberg, D.C. and Numbers, R.L. (eds). God and nature.Berkeley: University of California Press. 322- 350.
Ospovat, A.M. 1978. Four hitherto unpublished geological lectures given by Sir Humphrey Davy in 1805 from manuscripts belonging to the Royal Society of Cornwall with introduction and notes by Alexander M. Ospovat.Penzance: The Royal Geological Society of Cornwall.
Prior, M.E. 1954. Bacon's Man of Science. Journal of the History of Ideas. XV.
Rudwick, M.J.S. 1986. The shape and meaning of earth history. In: Lindberg, D.C. and Numbers, R.L. (eds). God and nature. Berkeley: University of California Press. 296-321.
Schaeffer, F.A. 1968. Escape from Reason. London: Inter- varsity Fellowship.
Schaeffer, F.A. 1968. The God who is there. London: Hodder & Stoughton Ltd.
Shea, W.R. 1986. Galileo and the church. In: Lindberg, D.C. and Numbers, R.L. (eds). God and nature. Berkeley: University of California Press. 114-135.
Tyler, D.J. 1989. Religious presuppositions in historical geology. Origins.3(7), 13-16.
Westman, R.S. 1986. The Copernicans and the churches. In: Lindberg, D.C. and Numbers, R.L. (eds). God and nature. Berkeley: University of California Press. 76-113.
This paper was first presented to the 6th European Creationist Congress, Amersfoort, The Netherlands, in August 1995)
It is the intention to develop sections of this paper in more detailed
Tyler, D.J. 1996. The impact of the Copernican Revolution on biblical interpretation. Origins, (21), 2-8.
Tyler, D.J. 1997. The "double revelation" approach to knowledge: Aquinas, Galileo and Descartes. Origins, (23), in press.