It is often assumed that the Bible’s statements relating to natural phenomena can only reflect the inadequate scientific knowledge of the period when the relevant portion of it was written. This is often used to deflect from and ‘explain away’ the obvious conflict between Genesis and the current ‘scientific’ paradigm of origins and prehistory. However, as this article seeks to show, consideration of the hydrologic cycle indicates the divine inspiration of the text by revealing detailed knowledge of the physical world that was not understood by ‘science’ until many centuries, if not millennia, later.
The Bible contains many observations of the natural world. On the planetary side there are descriptions of landscapes, weather and storm conditions, and of rivers and oceans. On the biological side there are descriptions of species, habitats, and ecosystem functions. There are also statements of physical and biological processes and of changing environments. Whilst these statements may not seem unusual to a reader today, many of these statements may have seemed uncertain to readers when they were first recorded.
Perhaps the most common reference in the Bible to nature is to aspects of the hydrologic cycle, or the distribution and movement of water. Water is essential to life, a cleansing substance, and a necessary basis for any civilization. Water is also referred to in the Bible as a component of purification, festivals, and ceremonies. Not only are there many statements on the hydrologic cycle in the Bible, but when combined from the various books of the Bible they provide an accurate insight into most aspects of the movement of water and the processes associated with these movements.
As will be shown in this paper, through a focus primarily on the wisdom literature (especially the Books of Job, Ecclesiastes, and Psalms), an adequate scientific description of the hydrologic cycle evaded scholars till only a few hundred years ago, even though the major processes of the hydrologic cycle were recorded in the Bible.
The hydrologic cycle is simply the distribution and movement of water on our planet and it has a cyclic movement as suggested by the name (figure 1). Precipitation falls to the earth and may be temporarily held in freshwater surface storage, infiltrates into the ground where some of it is stored as soil water and groundwater, and some of it is immediately evaporated. That which cannot be stored or immediately returned to the atmosphere then finds its way into streams and rivers and eventually reaches lakes or the oceans. Waters retained temporarily in the soils or in depressions on the land are then transpired by plants (evapotranspiration) or eventually evaporated from soils and open water bodies back into the atmosphere, where they are blown around the globe to begin the cycle once again. Evaporation also occurs across the oceans. Obviously there is a lot more to it than this and we have skipped over many of the finer details (a more detailed description can be found in the introductory chapter of any hydrologic book) but the continuous and cyclic nature of this movement of water is quite apparent.
The hydrologic cycle is the planet’s cleansing system, removing dust from the atmosphere and flushing streams and rivers clean. It is also critical to all aspects of life as it is responsible for the breakdown and movement of nutrients and therefore the most important geologic process. A regular and consistent supply of clean water has been required by all civilizations and water has for most of civilized history been the major form of transport, particularly of goods and produce.
Before we examine the development of scientific thinking on the hydrologic cycle it is worthwhile noting that significant engineering and water supply systems were developed at the dawn of civilization before a clear understanding of certain aspects of the hydrologic cycle was developed. Andah1 observed that early civilizations were able to manipulate and manage surface water flows without a clear understanding of the hydrologic cycle per se, and that this was achieved through damming and irrigation. Shanan2 notes that rain-fed farming can be a risky venture, particularly if there is seasonal rainfall uncertainty, whereas irrigation reduces this uncertainty and allows farming in otherwise unproductive lands. Shanan quotes an inscription on the tomb of Queen Semiramis of Assyria (about 2000 BC): “I constrained the mighty river to flow according to my will and led its waters to fertilize lands that before had been barren and without inhabitants.”2
In Egypt, records of river heights (or stages) were collected from the Nile from the earliest days (as recorded on ancient manuscripts3) and a canal to transport potable water had been built between Cairo and the Suez.1 From other ancient civilizations Biswas4 provides an extensive list of major water infrastructures, including water supply works and flood control structures, well before 600 BC.
These irrigation and aqueduct systems were developed before a rudimentary knowledge of flow dynamics emerged with the pioneering fluid flow investigations of Hero of Alexandria sometime between 150 BC and AD 250.5 So it is important to understand this distinction between the simple use of water on the one hand and a thorough understanding of its movements and processes on the other. These early civilizations demonstrated that you did not need a full and thorough understanding of how natural processes worked before you could manipulate them (figure 2).
The ancient Greeks had various ideas on the hydrologic cycle. According to Thales of Miletus (late 6th–early 5th century BC) streams and rivers emerged from underground. There was believed to be a vast subterranean freshwater lake, connected to the surface of the world by chasms and through surface springs water then flowed out into the rivers of the world. Variations on this theme were expressed by numerous other Greek philosophers such as Plato and Anaxagoras of Clazomenae (500–428 BC) who believed the earth to be full of watery caverns that provided springs for rivers as well as rainfall.
Figure 2. The Aqueduct of Segovia in central Spain dates from around the 2nd century, and is an excellent example of the Roman Empire aqueducts that are still found across Europe, the Middle East, and North Africa. Its purpose was to transport water from nearby mountains, some 17 km away. Although the Roman engineers did not have a good understanding of the global water cycle, they nonetheless undertook significant water projects.
Aristotle’s (mid-3rd century BC) view was somewhat more accurate. He argued in his work Meteorologica:
Aristotle nonetheless remained convinced that subterranean water was the main source of stream flow. He believed it was ‘absurd’ “if one were to suppose that rivers drew all their water from the sources we see (for most rivers do flow from springs)”.6 Referring to Thales, Plato, and Aristotle, Dooge5 writes: “A common error in all their thinking was the firm conviction that rainfall was not sufficient to provide the flow of springs and rivers.”
Vitruvius, a 1st century BC Roman architect, provided a reasonable description of the water cycle for his time. He described precipitation processes and the relationships between precipitation and surface flow, and on the basis of these observations recognized that rivers were primarily derived from precipitation, not from springs. Nonetheless, Vitruvius’s concept was rejected by subsequent scholars.
With the emergence of modern science there remained uncertainty on why water continued to flow in rivers long after rainfall. Dooge5 notes that even Leonardo da Vinci postulated on the underground lifting mechanisms of water into the mountains in his writings (sometime between 1504 and 1506 AD) and that Galileo (around 1600 AD) was frustrated by stream flow.
It was not until the first quantitative measurement of the hydrologic cycle was made by Pierre Perrault in the 16th century that the argument was finally laid to rest. Perrault measured both precipitation and streamflow in the Seine basin in France and determined that the amount of water precipitated was six times that flowing in the river. In short, there was more than enough rainfall to keep the rivers flowing long after the last rain had ceased. In determining this, a more complete understanding of the hydrologic cycle finally emerged.
How old are the books of the Bible?
Before we compare what the Bible records about the hydrologic cycle with what the philosophers and scientists determined, we need to ensure that the two accounts are independent. To do so we need to understand when these books were written, to ensure that the Bible authors were not simply recording current world views of the hydrologic cycle.
The Book of Job, though written primarily as poetic dialogue on the theology of suffering from a Hebrew perspective, provides a rich source of commentary on the hydrologic cycle, and as such is a great place to start. But its author and age have been subject to considerable debate. Habel7 notes that “Scholars have proposed dates from the 10th century to the 4th century BC” and suggests this is because there are no historical events mentioned in Job. What we do know is that fragments of the Book of Job were found amongst the Dead Sea Scrolls,8 dated at around 200 BC, and that they were written in ‘paleo-Hebrew’ script. “The many rare words and textural disturbances make the Hebrew text of Job one of the most obscure in the OT.”9 Moreover:
Habel7 argues “the cumulative evidence may tend to suggest a postexilic era” (late 5th to 4th centuries BC). Numerous experts note that no Levitical institutions are mentioned and Job personally offers sacrifices typical of pre-Tabernacle days (Patriarch tradition). Harris8 states that “in view of patriarchal milieu, it seems possible to hold to a Mosaic or slightly pre-Mosaic date in accord with much older Jewish and Christian sentiment”. Hartley9 believes “the interplay between this book and other OT books, especially Isaiah, can best be accounted for by placing this work in the 7th century BC”. Regardless of these divergences, most experts propose a date for the Book of Job no later than the 4th century BC, and most likely much earlier, possibly pre-Mosaic.
Other references to the hydrologic cycle can be drawn from Genesis, Deuteronomy, Psalms, Ecclesiastes, and Isaiah. Whilst the earliest fragments of these are also to be found in the Dead Sea Scrolls (around 200 BC) there is little argument amongst scholars that they were in fact written much earlier (and placed with the Ark of the Covenant).
The balance of evidence strongly suggests these books of the Bible pre-date the Greek philosopher Thales. As we shall see in the following sections, there are also significant differences in these accounts and there is no evidence to suggest the reflections of Thales or of the author of Job were in any manner connected.
Biblical descriptions of the hydrologic cycle
Because water is a necessary component of life it is not surprising that the Bible has something to say on the distribution and movement of water. The Bible does not raise these matters in a scientific or explanatory manner. Rather, God speaks to His people using common language and common concepts. Water is a common topic.
The Book of Job makes a number of points on what we today call the hydrologic cycle. But unlike the reflections of Thales, Job provides a clear description of the concepts that underpin the hydrologic cycle:
As noted earlier, these verses were not primarily provided as explanations of a hydrologic cycle. Rather they were used as commonly understood images to illustrate God’s Kingdom, and in the scripture listed above of God’s authority over mankind. In Job 26:28 God uses the water cycle to demonstrate that He does not deal with His people by chance but that just as nature is bound by a set of decrees so too is God’s Kingdom bound by laws. Job 38:33–34 reiterates His dominion over the earth and these laws, challenging humanity to comprehend His authority. Having illustrated Job’s ignorance of these matters, Job 38:37 further highlights mankind’s weakness by focusing on their inability to comprehend the most visible works of nature.
Though the purpose of these verses was to illustrate God’s Kingdom, nonetheless they contain some powerful hydrologic concepts that were well beyond the thinking of natural philosophers and scholars of the day.
Firstly there is the concept of ‘laws’ or ‘decrees’. God is a rational being and here He exhibits this rationality by creating laws or decrees for what we now know to be the pathways of the hydrologic cycle.
This is perhaps a more important point than people today might realize. At the time of writing the Book of Job, other major civilizations were polytheistic (worshipped many gods). In polytheistic cultures explanations for the human spirit and the mysteries of the natural world were sought from many gods. Indeed the uncertainties in life were so common that virtually all city states would have their own resident god. For example, the patron goddess of Athens was Athena, whose statue was housed in the Parthenon. In polytheistic societies the concept that there were laws or decrees for natural phenomena was bordering on blasphemy. The irregularities of nature (flooding and droughts for example) were attributed to the gods who were unpredictable and potentially in conflict with each other. The idea that nature could be systematic and predictable, provided we understood the laws or decree of a creator God, was revolutionary.
Secondly, the concept of a cycle is established in Job—the drops of waters are drawn up from the ground (evaporation), distilled (cleansed), stored (water jars or clouds that do not burst), moved (pathways), converted to rain (condensation and precipitation) and returned to the ground ‘abundantly’ and blessedly for mankind. Though this cycle was later described by Aristotle and Seneca, neither believed that it could account for the observed streamflow. It was not until the 1st century BC that Vitruvius believed it to be sufficient and it was not until the 16th century AD that measurements were able to record that there was more than enough rainfall to keep streams flowing. Yet the Book of Job says that the rainfall is ‘abundant’ for man to use.
Ecclesiastes 1 provides a statement of important concepts underpinning the hydrologic cycle as we know it today.
Embedded in these verses are the concepts of a cycle and of a water balance (conservation of matter). Ecclesiastes was written hundreds of years before Vitruvius first echoed similar concepts.
Elsewhere in the Bible, various hydrologic processes are further described. Evaporation is recorded in a number of other books:
Figure 3. Dew is an essential source of moisture in Israel during the summer, being blown in from the Mediterranean Sea. God likens Himself to dew (Hosea 14:5) in that the Israelites needed Him to survive.
as is precipitation:
as well as the source of dew (atmospheric [figure 3]) and the storage of groundwaters:
the process of infiltration (soaking into the ground) as well as precipitation once again:
and the release of groundwaters through springs:
There are even insights into groundwater hydrology. Isaiah 4:3–5 refers to a ‘yaval’ or ‘yuval’ which is a “sudden flood that appears in a dry wash after a storm”10 and replenishes the water table in semi-arid areas, allowing willows with deep roots (but not grasses) to survive difficult years.
Again, these verses are not designed to ‘explain’ the hydrologic cycle, but to use visible works of nature as metaphors. Deuteronomy 33:13 for example, refers to Moses blessing Joseph prior to his death—that the Lord continue to provide precious dew during the long dry season throughout the summer months. According to Sansom11 this dew is critical to the economic viability of this region. Likewise Isaiah 55:10 is a promise that God’s divine truth (like precipitation) shall be fruitful and does not return to him void—the writer knows that water (an analogy for the living water) falls as rain and snow and returns as vapour from whence it came, and that before it does it provides moisture and nourishment for an eventual harvest (Pulpit Commentaries).
In summary, the physical descriptions of the water cycle used throughout the Bible to illustrate authority, blessings, and salvation are accurate. Unlike the scholarly enquiries between 600 BC and AD 1600, the Bible does not present uncertainty, inaccuracy, or contradiction with its description of hydrologic processes. The hydrologic cycle is not described as subterranean waters sucked up into the mountains, to flow forth as springs that feed the rivers of the world. Instead the Bible paints a flawless picture of the dynamics and components of the water cycle more than a thousand years before the first ‘scientific’ measurement confirmed that this was so.
Before we conclude, however, we need to ask the question: ‘Does the Bible ever state that waters emerging from underground are the primary source of waters responsible for sustaining life?’ Surprisingly it does, but on only one occasion.
The Garden of Eden was described as paradise on Earth, a land of plenty deriving its life-giving water as a matter of course from underground. But we turned our back on that paradise.
Finally, there are also a number of occasions when water flowed out from the ground when there were no natural springs but these are all described in the Bible as miracles, not laws. One occurred when the three kings were challenged by Moab:
Another is an Exodus miracle when water flowed from rock after being struck by Moses:
To reiterate—these were both announced by God as His work, His miracle, and outside of the laws that He decreed.
To summarize, the Bible accurately describes the hydrologic cycle of our planet and did so well before an accurate modern scientific account emerged.
A correct scientific understanding of the hydrologic cycle was a long time coming, but a divine explanation of this most critical life support system was provided to us from the beginning. Over 2000 years of scientific debate, observation, and measurement have now confirmed what God revealed (albeit in passing comments and analogies) to His chosen people.
What lessons can we learn from this?
Firstly, God does not hide difficult concepts from us—He does not protect us in our ignorance from the truth of His creation. Was the hydrologic cycle difficult to fathom? Absolutely, and to give the ancient philosophers due recognition it would be arrogant to assume that we wouldn’t have made the same mistakes of interpretation regarding the global hydrologic cycle if we did not have access to, and a belief in, a creator God who ‘decreed’ the laws of nature.
In particular, it could be argued that observational data (that which scientists use to generate hypotheses and ideas) could have been misleading in this case. What is meant by this? Quite simply, what we perceive nature does and what nature actually does can be quite different. For example, many people would agree with the statement that a bubbling stream in the mountain headwaters flows faster than the apparently sluggish river on the plains but this is often a perception. Velocity measurements show that in the majority of cases this is not so. It is merely our perception that the splashing loud waters in the hills are flowing fast. Likewise, when people see a major river flowing months after the last rainfall many are unlikely to believe that the river flow did in fact originate as rainfall months earlier and that it simply took its time to get to the river (via soil and groundwater flow). To reiterate this point then—God did not simplify His revealed word because it would have been difficult for people of that era to fathom. So why do we think that He may have done so in other Books and in other accounts (such as Genesis)?
Secondly, this account illustrates quite clearly that when science and the Bible are at odds, science can be wrong. But all too often scientists seek alternative explanations. For example, when commenting on the stagnation of scientific enquiry into research on the hydrologic cycle during the Middle Ages (after the early achievements of Greek and Roman philosophers) Bulu3 makes a mistake common to scientists: “Understanding and investigating … nature had almost stopped because of the power of the Christian Church.” This stagnation instead stemmed from decentralized communities and governance following the collapse of the Roman Empire, increasing reliance on local technologies such as watermills rather than canals, and a reduction in slave labour for large infrastructural developments.5 Despite the incorrect beliefs of scientists like Bulu, scholarly thinking on nature was promoted by the church, as evidenced for example by Bartholoeus Anglicus (about AD 1250), a Franciscan professor at the University of Paris, who examined the lifting mechanism to get water into the mountains.
After 2,000 years of pondering, observing, and measuring, do we now fully understand how this global hydrologic system works? If we do, why then are rainfall predictions still estimates only? And why aren’t scientists able to predict the severity of the next flood or drought? We still need to ask the question—will we ever fully understand this cycle? Perhaps we have already been given the answer to that question in Job: “Indeed, can anyone understand the spreading of clouds, the thunder from His canopy?” (Job 36:29).
I would like to thank the two unknown reviewers for their insightful comments.