Uniformitarianism

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.[1][2] It refers to invariance in the metaphysical principles underpinning science, such as the constancy of cause and effect throughout space-time,[3] but has also been used to describe spatiotemporal invariance of physical laws.[4] Though an unprovable postulate that cannot be verified using the scientific method, uniformitarianism has been a key first principle of virtually all fields of science.[5]

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.[6] Coined by William Whewell, it was originally proposed in contrast to catastrophism[7] 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.[8] Hutton's work was later refined by scientist John Playfair and popularised by geologist Charles Lyell's Principles of Geology in 1830.[9] Today, Earth's history is considered to have been a slow, gradual process, punctuated by occasional natural catastrophic events.

Hutton Unconformity, Jedburgh
Hutton's Unconformity at Jedburgh.
Above: John Clerk of Eldin's 1787 illustration.
Below: 2003 photograph.

History

18th century

Siccar point SE cliff
Cliff at the east of Siccar Point in Berwickshire, showing the near-horizontal red sandstone layers above vertically tilted greywacke rocks.

The earlier conceptions likely 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.[10][11]

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.[12]

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.[13][14] 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.[15] 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.[16] Playfair later recalled that "the mind seemed to grow giddy by looking so far into the abyss of time",[17] 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".[18]

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.[19]

19th century

Lyell 1840
Charles Lyell at the British Association meeting in Glasgow 1840

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,[20] 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.

Systems of inorganic earth history

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.[21] 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.[22]

Methodological
assumption concerning
kind of process
Substantive claim
concerning state
Substantive claim
Concerning rate
System of Inorganic
Earth history
Promoters[23]
Same Kind of processes
that exist today
Actualism
Steady State
Non-directionalism
Constant Rate
Gradualism
Actualistic
Non-directional
Gradualism
Most of Hutton, Playfair, Lyell
Changing Rate
Catastrophism
Actualistic
Non-directional
Catastrophism
Hall
Changing State
Directionalism
Constant Rate
Gradualism
Actualistic
Directional
Gradualism
Small part of Hutton, Cotta, Darwin
Changing Rate
Catastrophism
Actualistic
Directional
Catastrophism
Hooke, Steno, Lehmann, Pallas,
de Saussure, Werner and geognosists,
Elis de Beaumont and followers
Different Kind of processes
than exist today
Non-Actualism
Steady State
Non-directionalism
Constant Rate
Gradualism
Non-Actualistic
Non-directional
Gradualism
Carpenter
Changing Rate
Catastrophism
Non-Actualistic
Non-directional
Catastrophism
Bonnet, Cuvier
Changing State
Directionalism
Constant Rate
Gradualism
Non-Actualistic
directional
Gradualism
De Mallet, Buffon
Changing Rate
Catastrophism
Non-Actualistic
Directional
Catastrophism
Restoration cosmogonists,
English diluvialists,
Scriptural geologists

Lyell's uniformitarianism

According to Reijer Hooykaas (1963), Lyell's uniformitarianism is a family of four related propositions, not a single idea:[24]

  • Uniformity of law – the laws of nature are constant across time and space.
  • Uniformity of methodology – the appropriate hypotheses for explaining the geological past are those with analogy today.
  • Uniformity of kind – past and present causes are all of the same kind, have the same energy, and produce the same effects.
  • Uniformity of degree – geological circumstances have remained the same over time.

None of these connotations requires another, and they are not all equally inferred by uniformitarians.[25]

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.[26]

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."[27]

  • Uniformity of law across time and space: Natural laws are constant across space and time.[28]
The axiom of uniformity of law [2][5][28] is necessary in order for scientists to extrapolate (by inductive inference) into the unobservable past.[2][28] The constancy of natural laws must be assumed in the study of the past; else we cannot meaningfully study it.[2][5][28][29]
  • Uniformity of process across time and space: Natural processes are constant across time and space.
Though similar to uniformity of law, this second a priori assumption, shared by the vast majority of scientists, deals with geological causes, not physico-chemical laws.[30] The past is to be explained by processes acting currently in time and space rather than inventing extra esoteric or unknown processes without good reason,[31][32] otherwise known as parsimony or Occam's razor.

The substantive hypotheses were controversial and, in some cases, accepted by few.[26] 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[27] that come before one can do science and so cannot be tested or falsified by science.

  • Uniformity of rate across time and space: Change is typically slow, steady, and gradual.[27]
Uniformity of rate (or gradualism) is what most people (including geologists) think of when they hear the word "uniformitarianism," confusing this hypothesis with the entire definition. As late as 1990, Lemon, in his textbook of stratigraphy, affirmed that "The uniformitarian view of earth history held that all geologic processes proceed continuously and at a very slow pace."[33]
Gould explained Hutton's view of uniformity of rate; mountain ranges or grand canyons are built by accumulation of nearly insensible changes added up through vast time. Some major events such as floods, earthquakes, and eruptions, do occur. But these catastrophes are strictly local. They neither occurred in the past, nor shall happen in the future, at any greater frequency or extent than they display at present. In particular, the whole earth is never convulsed at once.[34]
  • Uniformity of state across time and space: Change is evenly distributed throughout space and time.[35]
The uniformity of state hypothesis implies that throughout the history of our earth there is no progress in any inexorable direction. The planet has almost always looked and behaved as it does now. Change is continuous, but leads nowhere. The earth is in balance: a dynamic steady state.[35]

20th century

Stephen Jay Gould's first scientific paper, Is uniformitarianism necessary? (1965), reduced these four assumptions to two.[36] 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"[37] 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.[38] 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."[39]

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.[40] The present may not be a long enough key to penetrate the deep lock of the past.[41] 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."[42]

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.[43] 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.

See also

Notes

  1. ^ Gordon, 2013: 79
  2. ^ a b c d Gould 1965, pp. 223–228, "The assumption of spatial and temporal invariance of natural laws is by no means unique to geology since it amounts to a warrant for inductive inference which, as Bacon showed nearly four hundred years ago, is the basic mode of reasoning in empirical science. Without assuming this spatial and temporal invariance, we have no basis for extrapolating from the known to the unknown and, therefore, no way of reaching general conclusions from a finite number of observations."
  3. ^ Gordon, 2013: 82; "The uniformitarian principle assumes that the behavior of nature is regular and indicative of an objective causal structure in which presently operative causes may be projected into the past to explain the historical development of the physical world and projected into the future for the purposes of prediction and control. In short, it involves the process of inferring past causes from presently observable effects under the assumption that the fundamental causal regularities of the world have not changed over time."
  4. ^ Strahler, A.N. 1987. Science and Earth History- The Evolution/Creation Controversy, Prometheus Books, Amherst, New York, USA. p. 194: “Under the updated statement of a useful principle of uniformitarianism it boils down essentially to affirmation of the validity of universal scientific laws through time and space, coupled with a rejection of supernatural causes.” p. 62: “In cosmology, the study of the structure and evolution of the universe, it is assumed that the laws of physics are similar throughout the entire universe.”
  5. ^ a b c Simpson 1963, pp. 24–48, "Uniformity is an unprovable postulate justified, or indeed required, on two grounds. First, nothing in our incomplete but extensive knowledge of history disagrees with it. Second, only with this postulate is a rational interpretation of history possible, and we are justified in seeking—as scientists we must seek—such a rational interpretation."
  6. ^ FARIA, Felipe. Actualismo,Catastrofismo y Uniformitarismo. In: Pérez, María Luisa Bacarlett & Caponi, Gustavo. Pensar la vida: Filosofía, naturaleza y evolución. Toluca: Universidad Autónoma del Estado de México, p. 55-80, 2015.[1]
  7. ^ Pidwirny & Scott 1999, "the idea that Earth was shaped by a series of sudden, short-lived, violent events."
  8. ^ James, Hutton (1785). Theory of the Earth. CreateSpace Independent Publishing.
  9. ^ "Uniformitarianism: World of Earth Science".
  10. ^ Bowler 2003, pp. 57–62
  11. ^ Hutton, J. (1785). "Abstract, The System of the Earth, Its Duration and Stability". Archived from the original on 2008-09-07. 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.
  12. ^ Concerning the System of the Earth Archived 2008-09-07 at the Wayback Machine abstract, as read by James Hutton at a meeting of the Royal Society of Edinburgh on 4 July 1785, printed and circulated privately.
  13. ^ Robert Macfarlane (13 September 2003). "Glimpses into the abyss of time". The Spectator. Review of Repcheck's The Man Who Found Time. Archived from the original on 1 November 2007. 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.
  14. ^ "Scottish Geology – Glen Tilt". Archived from the original on 2006-06-16.
  15. ^ "Jedburgh: Hutton's Unconformity". Jedburgh online. Archived from the original on 2009-07-29. 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.
  16. ^ "Hutton's Unconformity". Archived from the original on 2015-09-24
  17. ^ John Playfair (1999). "Hutton's Unconformity". Transactions of the Royal Society of Edinburgh, vol. V, pt. III, 1805, quoted in Natural History, June 1999. Archived from the original on 2005-01-07.
  18. ^ Keith Stewart Thomson (May–June 2001). "Vestiges of James Hutton". American Scientist online. p. 212. doi:10.1511/2001.3.212. Archived from the original on 2011-06-11. 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.
  19. ^ Bowler 2003, pp. 111–117
  20. ^ Wilson, Leonard G. "Charles Lyell" Dictionary of Scientific Biography. Ed. Charles Coulston Gillispie. Vol. VIII. Pennsylvania, Charles Scribner's Sons, 1973
  21. ^ Huggett, Richard (1990). Catastophism: Systems of Earth History. London: Edward Arnold. p. 34.
  22. ^ Huggett, Richard (1990). Catastophism: Systems of Earth History. London: Edward Arnold. p. 33.
  23. ^ Huggett, Richard (1990). Catastophism: Systems of Earth History. London: Edward Arnold. p. 35.
  24. ^ Reijer Hooykaas, Natural Law and Divine Miracle: The Principle of Uniformity in Geology, Biology, and Theology, Leiden: EJ Brill, 1963.
  25. ^ David Cahan, 2003, From Natural Philosophy to the Sciences, p 95 ISBN 978-0-226-08928-7.
  26. ^ a b Gould, Stephen J (1987). Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time. Cambridge, MA: Harvard University Press. p. 118.
  27. ^ a b c Gould, Stephen J (1987). Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time. Cambridge, MA: Harvard University Press. p. 120. ISBN 0674891996.
  28. ^ a b c d Gould 1987, p. 119, "Making inferences about the past is wrapped up in the difference between studying the observable and the unobservable. In the observable, erroneous beliefs can be proven wrong and be inductively corrected by other observations. This is Popper's principle of falsifiability. However, past processes are not observable by their very nature. Therefore, 'the invariance of nature's laws must be assumed to come to conclusions about the past."
  29. ^ Hutton 1795, p. 297, "If the stone, for example, which fell today, were to rise again tomorrow, there would be an end of natural philosophy [i.e., science], our principles would fail, and we would no longer investigate the rules of nature from our observations."
  30. ^ Gould 1984, p. 11, "As such, it is another a priori methodological assumption shared by most scientists and not a statement about the empirical world."
  31. ^ Gould 1987, p. 120,"We should try to explain the past by causes now in operation without inventing extra, fancy, or unknown causes, however plausible in logic, if available processes suffice."
  32. ^ Hooykaas 1963, p. 38, ="Strict uniformitarianism may often be a guarantee against pseudo-scientific phantasies and loose conjectures, but it makes one easily forget that the principle of uniformity is not a law, not a rule established after comparison of facts, but a methodological principle, preceding the observation of facts . . . It is the logical principle of parsimony of causes and of economy of scientific notions. By explaining past changes by analogy with present phenomena, a limit is set to conjecture, for there is only one way in which two things are equal, but there are an infinity of ways in which they could be supposed different."
  33. ^ Lemon, R. R. 1990. Principles of stratigraphy. Columbus, Ohio: Merrill Publishing Company. p. 30
  34. ^ Gould, Stephen J (1987). Time _s Arrow, Time _s Cycle: Myth and Metaphor in the Discovery of Geological Time. Cambridge, MA: Harvard University Press. pp. 120–121.
  35. ^ a b Gould, Stephen J (1987). Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time. Cambridge, MA: Harvard University Press. p. 123.
  36. ^ Gould, S. J. (1965). "Is uniformitarianism necessary?". American Journal of Science. 263: 223–228. Bibcode:1965AmJS..263..223G. doi:10.2475/ajs.263.3.223.
  37. ^ William J. Whewell, Principles of Geology, Charles Leyell, vol. II, London, 1832: Quart. Rev., v. 47, p. 103-123.
  38. ^ Allen, E. A., et al., 1986, Cataclysms on the Columbia, Timber Press, Portland, OR. ISBN 978-0-88192-067-3
    • "Bretz knew that the very idea of catastrophic flooding would threaten and anger the geological community. And here's why: among geologists in the 1920s, catastrophic explanations for geological events (other than volcanos or earthquakes) were considered wrong minded to the point of heresy." p. 42.
    • "Consider, then, what Bretz was up against. The very word 'Catastrophism' was heinous in the ears of geologists. ... It was a step backwards, a betrayal of all that geological science had fought to gain. It was heresy of the worst order." p. 44
    • "It was inevitable that sooner or later the geological community would rise up and attempt to defeat Bretz's 'outrageous hypothesis.'" p 49
    • "Nearly 50 years had passed since Bretz first proposed the idea of catastorphic flooding, and now in 1971 his arguments had become a standard of geological thinking." p. 71
  39. ^ Ager, Derek V. (1993). The Nature of the Stratigraphical Record (3rd ed.). Chichester, New York, Brisbane, Toronto, Singapore: John Wiley & Sons. pp. 83–84. ISBN 0-471-93808-4.
  40. ^ Smith, Gary A; Aurora Pun (2006). How Does Earth Work: Physical geology and the Process of Science (textbook). New Jersey: Pearson/Prentice Hall. p. 12. ISBN 0-13-034129-0.
  41. ^ Ager, Derek V. (1993). The Nature of the Stratigraphical Record (3rd ed.). Chichester, New York, Brisbane, Toronto, Singapore: John Wiley & Sons. p. 81. ISBN 0-471-93808-4.
  42. ^ Gould, Stephen J (1987). Time _s Arrow, Time _s Cycle: Myth and Metaphor in the Discovery of Geological Time. Cambridge, MA: Harvard University Press. p. 174.
  43. ^ The Columbia Encyclopedia Sixth Edition, uniformitarianism Archived 2006-06-24 at the Wayback Machine © 2007 Columbia University Press.

References

  • Bowler, Peter J. (2003). Evolution: The History of an Idea (3rd ed.). University of California Press. ISBN 0-520-23693-9.
  • Gordon, B. L. (2013). "In Defense of Uniformitarianism". Perspectives on Science and Christian Faith. 65: 79–86.
  • Gould, S. J. (1965). "Is uniformitarianism necessary?". American Journal of Science. 263: 223–228. Bibcode:1965AmJS..263..223G. doi:10.2475/ajs.263.3.223.
  • Gould, S. J. (1984). "Toward the vindication of punctuational change in catastrophes and earth history". In Berggren, W. A.; Van Couvering, J. A. (eds.). In Catastrophes and Earth History. Princeton, New Jersey: Princeton University Press. p. 11.
  • Gould, Stephen J (1987). Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time. Cambridge, MA: Harvard University Press. p. 119.
  • Hooykaas, R. (1963). The principle of uniformity in geology, biology, and theology. London: E.J. Brill. p. 38.
  • Hutton, J (1795). Theory of the Earth with Proofs and Illustrations. p. 297.
  • Simpson, G. G. (1963). "Historical science". In Albritton, Jr., C. C. (ed.). Fabric of geology. Stanford, California: Freeman, Cooper, and Company. pp. 24–48.
Web

External links

Antediluvian

The Antediluvian (alternatively Pre-Diluvian or Pre-Flood period) is the time period referred to in the Bible between the fall of humans and the Genesis flood narrative in the biblical cosmology. The narrative takes up chapters 1–6 (excluding the flood narrative) of the Book of Genesis. The term found its way into early geology and science until the late Victorian era. Colloquially, the term is used to refer to any ancient and murky period.

Catastrophism

Catastrophism was the theory that the Earth had largely been shaped by sudden, short-lived, violent events, possibly worldwide in scope. This was in contrast to uniformitarianism (sometimes described as gradualism), 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 (such as erosion) 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.

Catastrophism held that geological epochs had ended with violent and sudden natural catastrophes such as great floods and the rapid formation of major mountain chains. Plants and animals living in the parts of the world where such events occurred were made extinct, being replaced abruptly by the new forms whose fossils defined the geological strata. Some catastrophists attempted to relate at least one such change to the Biblical account of Noah's flood.

The concept was first popularised by the early 19th-century French scientist Georges Cuvier, who proposed that new life forms had moved in from other areas after local floods, and avoided religious or metaphysical speculation in his scientific writings.

Charles Lyell

Sir Charles Lyell, 1st Baronet, (14 November 1797 – 22 February 1875) was a Scottish geologist who popularised the revolutionary work of James Hutton. He is best known as the author of Principles of Geology, which presented uniformitarianism–the idea that the Earth was shaped by the same scientific processes still in operation today–to the broad general public. Principles of Geology also challenged theories popularised by Georges Cuvier, which were the most accepted and circulated ideas about geology in Europe at the time.His scientific contributions included an explanation of earthquakes, the theory of gradual "backed up-building" of volcanoes, and in stratigraphy the division of the Tertiary period into the Pliocene, Miocene, and Eocene. He also coined the currently-used names for geological eras, Palaeozoic, Mesozoic and Cenozoic. He incorrectly conjectured that icebergs may be the emphasis behind the transport of glacial erratics, and that silty loess deposits might have settled out of flood waters.

Lyell, following deistic traditions, favoured an indefinitely long age for the earth, despite geological evidence suggesting an old but finite age. He was a close friend of Charles Darwin, and contributed significantly to Darwin's thinking on the processes involved in evolution. He helped to arrange the simultaneous publication in 1858 of papers by Darwin and Alfred Russel Wallace on natural selection, despite his personal religious qualms about the theory. He later published evidence from geology of the time man had existed on Earth.

Charles Lyell (disambiguation)

Sir Charles Lyell (1797–1875) was a geologist and populariser of uniformitarianism.

Charles Lyell may also refer to:

Charles Henry Lyell (1875–1918), Liberal MP

Charles Lyell, 2nd Baron Lyell (1913–1943), Victoria Cross recipient, son of the Liberal MP

Charles Lyell, 3rd Baron Lyell (1939–2017), Conservative member of the House of Lords, son of the 2nd Baron

Charles Lyell (botanist) (1767–1849), English botanist and translator of Dante

Geologist

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.

Geologists work in the energy and mining sectors searching for natural resources such as petroleum, natural gas, precious and base metals. They are also in the forefront of preventing and mitigating damage from natural hazards and disasters such as earthquakes, volcanoes, tsunamis and landslides. Their studies are used to warn the general public of the occurrence of these events. Geologists are also important contributors to climate change discussions.

Gradualism

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.

Hierarchical epistemology

Hierarchical epistemology is a theory of knowledge which posits that beings have different access to reality depending on their ontological rank.

Historical geology

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.

Economic geology, the search for and extraction of fuel and raw materials, is heavily dependent on an understanding of the geological history of an area. Environmental geology, including most importantly the geologic hazards of earthquakes and volcanism, must also include a detailed knowledge of geologic history.

Hutton's Unconformity

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.

An unconformity is any break in the normal progression of sedimentary deposits, which are laid the newer on top of the older.

In his search, Hutton and colleagues examined sea cliffs and found several locations where two adjoining rock types had been laid bare, the most noted being at Siccar Point.

James Hutton

James Hutton ( ; 3 June 1726 – 26 March 1797) 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".Through observation and carefully reasoned geological arguments, Hutton came to believe that the Earth was perpetually being formed; he recognised that the history of Earth could be determined by understanding how processes such as erosion and sedimentation work in the present day. His theories of geology and geologic time, also called deep time, came to be included in theories which were called plutonism and uniformitarianism. Some of his writings anticipated the Gaia hypothesis.

John Playfair

John Playfair FRSE, FRS (10 March 1748 – 20 July 1819) was a Church of Scotland minister, remembered as a scientist and mathematician, and a professor of natural philosophy at the University of Edinburgh. He is best known for his book Illustrations of the Huttonian Theory of the Earth (1802), which summarised the work of James Hutton. It was through this book that Hutton's principle of uniformitarianism, later taken up by Charles Lyell, first reached a wide audience. Playfair's textbook Elements of Geometry made a brief expression of Euclid's parallel postulate known now as Playfair's axiom.

In 1783 he was a co-founder of the Royal Society of Edinburgh. He served as General Secretary to the society 1798–1819.

List of epistemologists

This is a list of epistemologists, that is, people who theorize about the nature of knowledge, belief formation and the nature of justification.

Neptunism

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 theory took its name from Neptune, the ancient Roman god of the sea. There was considerable debate between its proponents (neptunists) and those favouring a rival theory known as plutonism which gave a significant role to volcanic origins, and which in modified form replaced neptunism in the early 19th century as the principle of uniformitarianism was shown to fit better with the geological facts as they became better known.

Modern geology acknowledges many different forms of rock formation, and explains the formation of sedimentary rock through processes very similar to those described by neptunism.

Paleoecology

Paleoecology (also spelled palaeoecology) is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs a variety of fields including paleontology, ecology, climatology and biology.

Paleoecology emerged out of the field of paleontology in the 1950s, though paleontologists have conducted paleoecological studies since the creation of paleontology in the 1700s and 1800s. Combining the investigative approach of searching for fossils with the theoretical approach of Charles Darwin and Alexander von Humboldt, paleoecology began as paleontologists began examining both the ancient organisms they discovered and the reconstructed environments in which they lived. Visual depictions of past marine and terrestrial communities has been considered an early form of paleoecology.

Plutonism

Plutonism (or volcanism) 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.Abbé Anton Moro, who had studied volcanic islands, first proposed the theory before 1750, and James Hutton subsequently developed it as part of his Theory of the Earth,

published in 1788. The idea contested Abraham Werner's neptunist theory which proposed that the Earth had formed from a mass of water and suspended material which had formed rocks as layers of deposited sediment which became the continents when the water retreated, further layers being deposited by floods and some volcanic activity.

Plutonists strongly disputed the neptunist view that rocks had formed by processes that no longer operated, instead supporting Hutton's uniformitarianism. A key issue of the debate revolved around the neptunist belief that basalt was sedimentary, and some fossils had been found in it. Against this, Hutton's friend John Playfair (1748-1819) argued that this rock contained no fossils as it had formed from molten magma, and it had been found cutting through other rocks in volcanic dykes. The arguments continued into the early 19th century, and eventually the plutonist views on the origin of rocks prevailed in the wake of the work of Charles Lyell in the 1830s. However, geologists regard sedimentary rocks such as limestone as having resulted from processes like those described by the neptunists, and so modern petrological theory can be seen as a synthesis of the two approaches.

Principles of Geology

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.

Relative dating

Relative dating is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age (i.e. estimated 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.

Time's Arrow, Time's Cycle

Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time is a 1987 history of geology by Stephen Jay Gould offering a historical account of the conceptualization of Deep Time and uniformitarianism using the works of Thomas Burnet, James Hutton, and Charles Lyell.

William Whewell

Rev Dr William Whewell DD HFRSE ( HEW-əl; 24 May 1794 – 6 March 1866) 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.

What is most often remarked about Whewell is the breadth of his endeavours. In a time of increasing specialisation, Whewell appears as a vestige of an earlier era when natural philosophers dabbled in a bit of everything. He researched ocean tides (for which he won the Royal Medal), published work in the disciplines of mechanics, physics, geology, astronomy, and economics, while also finding the time to compose poetry, author a Bridgewater Treatise, translate the works of Goethe, and write sermons and theological tracts. In mathematics, Whewell introduced what is now called the Whewell equation, an equation defining the shape of a curve without reference to an arbitrarily chosen coordinate system.

One of Whewell's greatest gifts to science was his wordsmithing. He often corresponded with many in his field and helped them come up with new terms for their discoveries. Whewell contributed the terms scientist, physicist, linguistics, consilience, catastrophism, uniformitarianism, and astigmatism amongst others; Whewell suggested the terms electrode, ion, dielectric, anode, and cathode to Michael Faraday.Whewell died in Cambridge in 1866 as a result of a fall from his horse.

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