Uniformitarianism, also known as the Doctrine of Uniformity, is the assumption that the same natural laws and processes that operate in our present-day scientific observations have always operated in the universe in the past and apply everywhere in the universe.It refers to invariance in the metaphysical principles underpinning science, such as the constancy of cause and effect throughout space-time, but has also been used to describe spatiotemporal invariance of physical laws. Though an unprovable postulate that cannot be verified using the scientific method, some consider that uniformitarianism should be a required first principle in scientific research. Other scientists disagree and consider that nature is not absolutely uniform, even though it does exhibit certain regularities.
Metaphysics is the branch of philosophy that examines the fundamental nature of reality, including the relationship between mind and matter, between substance and attribute, and between potentiality and actuality. The word "metaphysics" comes from two Greek words that, together, literally mean "after or behind or among [the study of] the natural". It has been suggested that the term might have been coined by a first century CE editor who assembled various small selections of Aristotle’s works into the treatise we now know by the name Metaphysics.
Causality is efficacy, by which one process or state, a cause, contributes to the production of another process or state, an effect, where the cause is partly responsible for the effect, and the effect is partly dependent on the cause. In general, a process has many causes, which are also said to be causal factors for it, and all lie in its past. An effect can in turn be a cause of, or causal factor for, many other effects, which all lie in its future. Multiple philosophers have believed that causality is metaphysically prior to notions of time and space.
A first principle is a basic, foundational, self-evident proposition or assumption that cannot be deduced from any other proposition or assumption. In philosophy, first principles are taught by Aristotelians, and nuanced versions of first principles are referred to as postulates by Kantians. In mathematics, first principles are referred to as axioms or postulates. In physics and other sciences, theoretical work is said to be from first principles, or ab initio, if it starts directly at the level of established science and does not make assumptions such as empirical model and parameter fitting.
In geology, uniformitarianism has included the gradualistic concept that "the present is the key to the past" and that geological events occur at the same rate now as they have always done, though many modern geologists no longer hold to a strict gradualism.Coined by William Whewell, it was originally proposed in contrast to catastrophism by British naturalists in the late 18th century, starting with the work of the geologist James Hutton in his many books including Theory of the Earth . Hutton's work was later refined by scientist John Playfair and popularised by geologist Charles Lyell's Principles of Geology in 1830. Today, Earth's history is considered to have been a slow, gradual process, punctuated by occasional natural catastrophic events.
Geology is an earth science concerned with the solid Earth, the rocks of which it is composed, and the processes by which they change over time. Geology can also include the study of the solid features of any terrestrial planet or natural satellite such as Mars or the Moon. Modern geology significantly overlaps all other earth sciences, including hydrology and the atmospheric sciences, and so is treated as one major aspect of integrated earth system science and planetary science.
Gradualism, from the Latin gradus ("step"), is a hypothesis, a theory or a tenet assuming that change comes about gradually or that variation is gradual in nature and happens over time as opposed to in large steps. Uniformitarianism, incrementalism, and reformism are similar concepts.
Rev Dr William Whewell DD HFRSE was an English polymath, scientist, Anglican priest, philosopher, theologian, and historian of science. He was Master of Trinity College, Cambridge. In his time as a student there, he achieved distinction in both poetry and mathematics.
The earlier conceptions[ which? ] likely[ original research? ] had little influence on 18th-century European geological explanations for the formation of Earth. Abraham Gottlob Werner (1749–1817) proposed Neptunism, where strata represented deposits from shrinking seas precipitated onto primordial rocks such as granite. In 1785 James Hutton proposed an opposing, self-maintaining infinite cycle based on natural history and not on the Biblical account.
Abraham Gottlob Werner was a German geologist who set out an early theory about the stratification of the Earth's crust and propounded a history of the Earth that came to be known as Neptunism. While most tenets of Neptunism were eventually set aside, Werner is remembered for his demonstration of chronological succession in rocks; for the zeal with which he infused his pupils; and for the impulse he thereby gave to the study of geology. He has been called the "father of German geology".
Neptunism is a superseded scientific theory of geology proposed by Abraham Gottlob Werner (1749–1817) in the late 18th century, proposing that rocks formed from the crystallisation of minerals in the early Earth's oceans.
The solid parts of the present land appear in general, to have been composed of the productions of the sea, and of other materials similar to those now found upon the shores. Hence we find reason to conclude:
- 1st, That the land on which we rest is not simple and original, but that it is a composition, and had been formed by the operation of second causes.
- 2nd, That before the present land was made, there had subsisted a world composed of sea and land, in which were tides and currents, with such operations at the bottom of the sea as now take place. And,
- Lastly, That while the present land was forming at the bottom of the ocean, the former land maintained plants and animals; at least the sea was then inhabited by animals, in a similar manner as it is at present.
Hence we are led to conclude, that the greater part of our land, if not the whole had been produced by operations natural to this globe; but that in order to make this land a permanent body, resisting the operations of the waters, two things had been required;
- 1st, The consolidation of masses formed by collections of loose or incoherent materials;
- 2ndly, The elevation of those consolidated masses from the bottom of the sea, the place where they were collected, to the stations in which they now remain above the level of the ocean.
Hutton then sought evidence to support his idea that there must have been repeated cycles, each involving deposition on the seabed, uplift with tilting and erosion, and then moving undersea again for further layers to be deposited. At Glen Tilt in the Cairngorm mountains he found granite penetrating metamorphic schists, in a way which indicated to him that the presumed primordial rock had been molten after the strata had formed.He had read about angular unconformities as interpreted by Neptunists, and found an unconformity at Jedburgh where layers of greywacke in the lower layers of the cliff face have been tilted almost vertically before being eroded to form a level plane, under horizontal layers of Old Red Sandstone. In the spring of 1788 he took a boat trip along the Berwickshire coast with John Playfair and the geologist Sir James Hall, and found a dramatic unconformity showing the same sequence at Siccar Point. Playfair later recalled that "the mind seemed to grow giddy by looking so far into the abyss of time", and Hutton concluded a 1788 paper he presented at the Royal Society of Edinburgh, later rewritten as a book, with the phrase "we find no vestige of a beginning, no prospect of an end".
The seabed is the bottom of the ocean.
In earth science, erosion is the action of surface processes that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, air (wind), plants, animals, and humans. In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, wind (aeolic) erosion, zoogenic erosion, and anthropogenic erosion. The particulate breakdown of rock or soil into clastic sediment is referred to as physical or mechanical erosion; this contrasts with chemical erosion, where soil or rock material is removed from an area by its dissolving into a solvent, followed by the flow away of that solution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres.
Glen Tilt is a glen in the extreme north of Perthshire, Scotland. Beginning at the confines of Aberdeenshire, it follows a South-westerly direction excepting for the last 4 miles, when it runs due south to Blair Atholl. It is watered throughout by the Tilt, which enters the Garry after a course of 14 miles, and receives on its right the Tarf, which forms some beautiful falls just above the confluence, and on the left the Fender, which has some fine falls also. The attempt of George Murray, 6th Duke of Atholl to close the glen to the public was successfully contested by the Scottish Rights of Way Society. The massive mountain of Beinn a' Ghlò and its three Munros Càrn nan Gabhar, Bràigh Coire Chruinn-bhalgain and Càrn Liath (975) dominate the glen's eastern lower half.
Both Playfair and Hall wrote their own books on the theory, and for decades robust debate continued between Hutton's supporters and the Neptunists. Georges Cuvier's paleontological work in the 1790s, which established the reality of extinction, explained this by local catastrophes, after which other fixed species repopulated the affected areas. In Britain, geologists adapted this idea into "diluvial theory" which proposed repeated worldwide annihilation and creation of new fixed species adapted to a changed environment, initially identifying the most recent catastrophe as the biblical flood.
Jean Léopold Nicolas Frédéric, Baron Cuvier, known as Georges Cuvier, was a French naturalist and zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in natural sciences research in the early 19th century and was instrumental in establishing the fields of comparative anatomy and paleontology through his work in comparing living animals with fossils.
The history of paleontology traces the history of the effort to understand the history of life on Earth by studying the fossil record left behind by living organisms. Since it is concerned with understanding living organisms of the past, paleontology can be considered to be a field of biology, but its historical development has been closely tied to geology and the effort to understand the history of Earth itself.
In biology, extinction is the termination of an organism or of a group of organisms (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" after a period of apparent absence.
From 1830 to 1833 Charles Lyell's multi-volume Principles of Geology was published. The work's subtitle was "An attempt to explain the former changes of the Earth's surface by reference to causes now in operation". He drew his explanations from field studies conducted directly before he went to work on the founding geology text,and developed Hutton's idea that the earth was shaped entirely by slow-moving forces still in operation today, acting over a very long period of time. The terms uniformitarianism for this idea, and catastrophism for the opposing viewpoint, were coined by William Whewell in a review of Lyell's book. Principles of Geology was the most influential geological work in the middle of the 19th century.
Sir Charles Lyell, 1st Baronet, was a Scottish geologist who demonstrated the power of existing natural causes in explaining Earth history. He is best known as the author of Principles of Geology, which presented for a wide public audience the idea that the Earth was shaped by the same natural processes still in operation today, operating at similar intensities. The philosopher William Whewell termed this gradualistic view "uniformitarianism" and contrasted it with catastrophism, which had been championed by Georges Cuvier and was better accepted in Europe. The combination of evidence and eloquence in Principles convinced a wide range of readers of the significance of "deep time" for understanding the Earth and environment.
Principles of Geology: being an attempt to explain the former changes of the Earth's surface, by reference to causes now in operation is a book by the Scottish geologist Charles Lyell that was first published in 3 volumes from 1830–1833. Lyell used the theory of Uniformitarianism to describe how the Earth's surface was changing over time. This theory was in direct contrast to the geological theory of Catastrophism. Many individuals believed in catastrophism to allow room for religious beliefs. For example, Noah's Flood could be described thus as a real geological event as catastrophism describes the changing of the Earth surface as one-time, violent events. Lyell challenged the believers of the catastrophic theory by studying Mount Etna in Sicily and describing the changes from one stratum to another and the fossil records within the rocks to prove that slow, gradual changes were the cause of the ever-changing Earth's surface. Lyell used geological proof to determine that the Earth was older than 6,000 years, as had been previously contested. The book shows that the processes that are occurring in the present are the same processes that occurred in the past.
Catastrophism is the theory that the Earth had largely been shaped by sudden, short-lived, violent events, possibly worldwide in scope. This is in contrast to uniformitarianism, in which slow incremental changes, such as erosion, created all the Earth's geological features. Uniformitarianism held that the present was the key to the past, and that all geological processes throughout the past were like those that can be observed now. Since the early disputes, a more inclusive and integrated view of geologic events has developed, in which the scientific consensus accepts that there were some catastrophic events in the geologic past, but these were explicable as extreme examples of natural processes which can occur.
Geoscientists support diverse systems of Earth history, the nature of which rest on a certain mixture of views about process, control, rate, and state which are preferred. Because geologists and geomorphologists tend to adopt opposite views over process, rate and state in the inorganic world, there are eight different systems of beliefs in the development of the terrestrial sphere.All geoscientists stand by the principle of uniformity of law. Most, but not all, are directed by the principle of simplicity. All make definite assertions about the quality of rate and state in the inorganic realm.
kind of process
|System of Inorganic|
|Same Kind of processes|
that exist today
|Most of Hutton, Playfair, Lyell|
|Small part of Hutton, Cotta, Darwin|
|Hooke, Steno, Lehmann, Pallas,|
de Saussure, Werner and geognosists,
Elis de Beaumont and followers
|Different Kind of processes|
than exist today
|De Mallet, Buffon|
According to Reijer Hooykaas (1963), Lyell's uniformitarianism is a family of four related propositions, not a single idea:
None of these connotations requires another, and they are not all equally inferred by uniformitarians.
Gould explained Lyell's propositions in Time's Arrow, Time's Cycle (1987), stating that Lyell conflated two different types of propositions: a pair of methodological assumptions with a pair of substantive hypotheses. The four together make up Lyell's uniformitarianism.
The two methodological assumptions below are accepted to be true by the majority of scientists and geologists. Gould claims that these philosophical propositions must be assumed before you can proceed as a scientist doing science. "You cannot go to a rocky outcrop and observe either the constancy of nature's laws or the working of unknown processes. It works the other way around." You first assume these propositions and "then you go to the outcrop."
The substantive hypotheses were controversial and, in some cases, accepted by few.These hypotheses are judged true or false on empirical grounds through scientific observation and repeated experimental data. This is in contrast with the previous two philosophical assumptions that come before one can do science and so cannot be tested or falsified by science.
Stephen Jay Gould's first scientific paper, Is uniformitarianism necessary? (1965), reduced these four assumptions to two.He dismissed the first principle, which asserted spatial and temporal invariance of natural laws, as no longer an issue of debate. He rejected the third (uniformity of rate) as an unjustified limitation on scientific inquiry, as it constrains past geologic rates and conditions to those of the present. So, Lyellian uniformitarianism was unnecessary.
Uniformitarianism was proposed in contrast to catastrophism, which states that the distant past "consisted of epochs of paroxysmal and catastrophic action interposed between periods of comparative tranquility"Especially in the late 19th and early 20th centuries, most geologists took this interpretation to mean that catastrophic events are not important in geologic time; one example of this is the debate of the formation of the Channeled Scablands due to the catastrophic Missoula glacial outburst floods. An important result of this debate and others was the re-clarification that, while the same principles operate in geologic time, catastrophic events that are infrequent on human time-scales can have important consequences in geologic history. Derek Ager has noted that "geologists do not deny uniformitarianism in its true sense, that is to say, of interpreting the past by means of the processes that are seen going on at the present day, so long as we remember that the periodic catastrophe is one of those processes. Those periodic catastrophes make more showing in the stratigraphical record than we have hitherto assumed."
Even Charles Lyell thought that ordinary geological processes would cause Niagara Falls to move upstream to Lake Erie within 10,000 years, leading to catastrophic flooding of a large part of North America.
Modern geologists do not apply uniformitarianism in the same way as Lyell. They question if rates of processes were uniform through time and only those values measured during the history of geology are to be accepted.The present may not be a long enough key to penetrate the deep lock of the past. Geologic processes may have been active at different rates in the past that humans have not observed. "By force of popularity, uniformity of rate has persisted to our present day. For more than a century, Lyell's rhetoric conflating axiom with hypotheses has descended in unmodified form. Many geologists have been stifled by the belief that proper methodology includes an a priori commitment to gradual change, and by a preference for explaining large-scale phenomena as the concatenation of innumerable tiny changes."
The current consensus is that Earth's history is a slow, gradual process punctuated by occasional natural catastrophic events that have affected Earth and its inhabitants. [ citation needed ]In practice it is reduced from Lyell's conflation, or blending, to simply the two philosophical assumptions. This is also known as the principle of geological actualism, which states that all past geological action was like all present geological action. The principle of actualism is the cornerstone of paleoecology.
As it is not in human record, but in natural history, that we are to look for the means of ascertaining what has already been, it is here proposed to examine the appearances of the earth, in order to be informed of operations which have been transacted in time past. It is thus that, from principles of natural philosophy, we may arrive at some knowledge of order and system in the economy of this globe, and may form a rational opinion with regard to the course of nature, or to events which are in time to happen.
Hutton possessed an instinctive ability to reverse physical processes – to read landscapes backwards, as it were. Fingering the white quartz which seamed the grey granite boulders in a Scottish glen, for instance, he understood the confrontation that had once occurred between the two types of rock, and he perceived how, under fantastic pressure, the molten quartz had forced its way into the weaknesses in the mother granite.
Whilst visiting Allar's Mill on the Jed Water, Hutton was delighted to see horizontal bands of red sandstone lying 'unconformably' on top of near vertical and folded bands of rock.
It is ironic that Hutton, the man whose prose style is usually dismissed as unreadable, should have coined one of the most memorable, and indeed lyrical, sentences in all science: "(in geology) we find no vestige of a beginning,—no prospect of an end". In those simple words, Hutton framed a concept that no one had previously contemplated, that the rocks making up the earth today have not, after all, been here since Creation.
James Hutton was a Scottish geologist, physician, chemical manufacturer, naturalist, and experimental agriculturalist. He originated the theory of uniformitarianism—a fundamental principle of geology—that explains the features of the Earth's crust by means of natural processes over geologic time. Hutton's work established geology as a science, and as a result he is referred to as the "Father of Modern Geology".
Deep time is the concept of geologic time. The modern philosophical concept was developed in the 18th century by Scottish geologist James Hutton (1726–1797). The age of the Earth has been determined to be, after a long and complex history of developments, around 4.55 billion years.
Historical geology or paleogeology is a discipline that uses the principles and techniques of geology to reconstruct and understand the geological history of Earth. It focuses on geologic processes that change the Earth's surface and subsurface; and the use of stratigraphy, structural geology and paleontology to tell the sequence of these events. It also focuses on the evolution of plants and animals during different time periods in the geological timescale. The discovery of radioactivity and the development of several radiometric dating techniques in the first half of the 20th century provided a means of deriving absolute versus relative ages of geologic history.
Flood geology is the attempt to interpret and reconcile geological features of the Earth in accordance with a literal belief in the global flood described in Genesis 6–8. In the early 19th century, diluvial geologists hypothesized that specific surface features were evidence of a worldwide flood which had followed earlier geological eras; after further investigation they agreed that these features resulted from local floods or glaciers. In the 20th century, young Earth creationists revived flood geology as an overarching concept in their opposition to evolution, assuming a recent six-day Creation and cataclysmic geological changes during the Biblical Deluge, and incorporating creationist explanations of the sequence of rock strata.
Relative dating is the science of determining the relative order of past events, without necessarily determining their absolute age. In geology, rock or superficial deposits, fossils and lithologies can be used to correlate one stratigraphic column with another. Prior to the discovery of radiometric dating in the early 20th century, which provided a means of absolute dating, archaeologists and geologists used relative dating to determine ages of materials. Though relative dating can only determine the sequential order in which a series of events occurred, not when they occurred, it remains a useful technique. Relative dating by biostratigraphy is the preferred method in paleontology and is, in some respects, more accurate. The Law of Superposition, which states that older layers will be deeper in a site than more recent layers, was the summary outcome of 'relative dating' as observed in geology from the 17th century to the early 20th century.
Plutonism is the geologic theory that the igneous rocks forming the Earth originated from intrusive magmatic activity, with a continuing gradual process of weathering and erosion wearing away rocks, which were then deposited on the sea bed, re-formed into layers of sedimentary rock by heat and pressure, and raised again. It proposes that basalt is solidified molten magma. The name plutonism references Pluto, the classical ruler of the underworld, while "volcanism" echoes the name of Vulcan, the ancient Roman god of fire and volcanoes. The Oxford English Dictionary traces use of the word "plutonists" to 1799, and the appearance of the word plutonism to 1842.
Siccar Point is a rocky promontory in the county of Berwickshire on the east coast of Scotland. It is famous in the history of geology for Hutton's Unconformity found in 1788, which James Hutton regarded as conclusive proof of his uniformitarian theory of geological development.
Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time is a 1987 history of geology by the paleontologist Stephen Jay Gould, in which the author offers a historical account of the conceptualization of Deep Time and uniformitarianism using the works of Thomas Burnet, James Hutton, and Charles Lyell.
Metaphysical naturalism is a philosophical worldview which holds that there is nothing but natural elements, principles, and relations of the kind studied by the natural sciences. Methodological naturalism is a philosophical basis for science, for which metaphysical naturalism provides only one possible ontological foundation. Broadly, the corresponding theological perspective is religious naturalism or spiritual naturalism. More specifically, metaphysical naturalism rejects the supernatural concepts and explanations that are part of many religions.
The following outline is provided as an overview of and topical guide to geology:
Hutton's Unconformity is a name given to various notable geological sites in Scotland identified by the 18th-century Scottish geologist James Hutton as places where the junction between two types of rock formations can be seen. This geological phenomenon marks the location where rock formations created at different times and by different forces adjoin. For Hutton, such an unconformity provided evidence for his Plutonist theories of uniformitarianism and the age of the Earth.
A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes the Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, although backgrounds in physics, chemistry, biology, and other sciences are also useful. Field work is an important component of geology, although many subdisciplines incorporate laboratory work.
A stratigraphic column is a representation used in geology and its subfield of stratigraphy to describe the vertical location of rock units in a particular area. A typical stratigraphic column shows a sequence of sedimentary rocks, with the oldest rocks on the bottom and the youngest on top.
Karl Ernst Adolf von Hoff was a German natural historian and geologist.
Theory of the Earth was a publication by James Hutton which laid the foundations for geology. In it he showed that the Earth is the product of natural forces. What could be seen happening today, over long periods of time, could produce what we see in the rocks. This idea, uniformitarianism, was used by Charles Lyell in his work, and Lyell's textbook was an important influence on Charles Darwin. The work was first published in 1788 by the Royal Society of Edinburgh, and later in 1795 as two book volumes.
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