17th Century Scientific Revolution in the Unfolding of the Age of Enlightenment

The Scientific Revolution inspired and “jumpstarted” the Enlightenment.  It could be argued that the Scientific Revolution itself started far earlier than the 17th Century.  Perhaps it started with Roger Bacon’s Opus Majus written in 1267, but not published for mass consumption until 1733, in which the good friar describes the scientific method of experimentation (1 )or perhaps it started with William of Ockham in the 14th Century, in that he helped “blaze a path . . . of logic and natural philosophy uninhibited by faith.”(2)  Regardless of when it started, the primary influence of the Scientific Revolution on the Enlightenment was: “. . . not a fixed set of beliefs but a way of thinking, a critical approach . . . for constructive thought and action.”(3)

Trailblazers of the Scientific Revolution were consumed not just with discovering the workings of nature through observation and experimentation but also with explaining them through describing general natural laws.  Take, for example, the science of astronomy that with the observations and discoveries of Tycho Brahe and Johannes Kepler finally managed to escape the dead hand of Aristotle and Ptolemy.  Kepler took Brahe’s observations and using careful mathematical calculations discovered and published his “Laws of Planetary Motion”.(4)

The ultimate expression of humanity discovering and then expressing newly found laws of nature during the Scientific Revolution was Sir Isaac Newton’s “Laws of Motion.”  Newton, it can be fairly said, created the science of Physics with the publication of his Principia Mathe-matica in 1687.(5)   He also made seminal contributions to the science of optics, including inventing the reflecting telescope and he, along with Gottfried Wilhelm Leibniz, invented Calculus.(6)

Some philosophers, seeing these and earlier discoveries, attempted to apply these kinds of natural and immutable laws to human behavior and human institutions.(7)  Perhaps the first of these was Thomas Hobbes.  Even though he died eight years before the publication of the Principia Mathematica, Hobbes believed that politics and government were subject to laws as clear, true and demonstrable as those of motion.  Hobbes laid out this concept in his great work; Leviathan published in 1651.(8)

Advancing from the ideas of Hobbes and Newton, as Peter Gay puts it; “the philosophes celebrated the Scientific Revolution, accepted its findings, and imitated its methods.” (9) The imitation of method consisted of applying, as Hobbes did, the paradigm that there were natural and uncontestable laws that were applicable to humans and their works.  That is to say that the social sciences such as political science, economics and history were subject to laws, just as the natural sciences, like physics and astronomy, were subject to such laws.  In short, the Enlightenment thinkers believed the scientific method could be used to “understand all life.” (10)

In the area of government and politics, John Locke followed Hobbes in an attempt to apply natural laws to those institutions. Locke’s primary idea is laid out in his An Essay Concerning the True Original, Extent and End of Civil Government, which is that all human are born with the natural rights to life, liberty and property.(11) Both Locke and Jean-Jacques Rousseau reached a social contract theory of government by extrapolating from these laws.  Of course, Locke, Rousseau and Hobbes each reached different conclusions regarding the natural rights of men and the social contract.(12)  Further, and perhaps most telling on the scientific veracity of the social contract theory was the vigorous historical criticism of the theory by David Hume.(13)

Adam Smith’s great work on economics, The Wealth of Nations, published in 1776, was not “self-consciously scientific”.  But still, The Wealth of Nations was Smith’s attempt to observe and theorize about economics as never before and to place economic activity in a context of fixed principles and to extrapolate economic laws from those principles.  In short, Smith’s work represented the “dawn of a science”, not its climax.  After all, it wasn’t until 1803 that the term “the science of political economy” was used in the English language, even though the term “economics” had entered French some ten years before Smith published his master work.(14)

History, as a philosophical and literary endeavor was also “becoming one of the sciences of man, less precise than the physical sciences, perhaps, but no less scientific for all that.”(15)  History, as a field of study, certainly was important to many of the philosophes.  For example, Hume was better known in his own day as a historian than as a philosopher(16) and his historical writings certainly paid better than his philosophical ones.(17)  Voltaire was a historian as well.(18) History was largely made into a science by the Enlightenment writers through their insistence on seeking accuracy, finding and using authentic sources and seeking “cause and effect” in history.(19)  This is just as the natural scientist seeks “cause and effect” in the natural world.  The best and most well known example of this is Gibbon’s masterwork, The Decline and Fall of the Roman Empire, which represents a very real attempt to rationalize historical inquiry and, as a true classic, escapes the bounds of its own time and is still read and cited today.(20)

Using Hume’s famous passages: “It is universally acknowledged that there is a great uniformity among the actions of men. . .” and that “the same motives always produce the same actions”(21) as a starting point, it may be fairly said that the philosphes created the science of psychology.(22) While not giving it the name, the Enlightenment writers invented the science of sociology as well, with Montesquieu as its first and greatest Enlightenment practitioner.  In these new social sciences the philosphes were trying to move from “statement of facts to general laws” and “imposes quantitative methods on qualitative experience”, all in an attempt to exchange “rational theory for guessing”.(23)

In conclusion, the primary issue that the Enlightenment, as a movement, had in the goal of finding and applying some kinds of immutable laws to human nature is demonstrated by the fact that the philosphes reached many different conclusions regarding government, history and the other social sciences.  If there were a set of absolute laws of human nature, as there are a set of absolute laws of the physical world, then no different conclusions could be possibly.  There would be one clear and correct answer.  However, these disagreements did not stop the Enlightenment philosophers from trying.  Perhaps the last word on how Scientific Revolution inspired the Enlightenment may be left to David Hume: “Even, Mathematics, Natural Philosophy, and Natural Religion, are in some measure dependent on the science of MAN; since the lie under the cognizance of men, and are judged of by their powers and faculties.”(24)

1 Robert Belle Burke, Introduction to The Opus Majus of Roger Bacon, Volume 1 by Roger Bacon, (Whitefish, MT: Kessinger Publishing, LLC, 2002), xiii.

2 Judith M Bennett and C Warren Hollister Medieval Europe: A Short History 10th ed. (New York: McGraw Hill co., 2006), 380.

3 Thomas Hankins, Science and the Enlightenment, Cambridge: Cambridge University Press, 1985), 2.

4 James R. Jacob, The Scientific Revolution: Aspirations and Achievements, 1500-1700 (Amherst, NY: Humanity Books, 1999), 41-45.

5 J. G. Crowther, The Social Relations of Science, (New York: The Macmillan Company, 1941), 433.

6 Jacob, The Scientific Revolution, 127.

7 Abraham S. Luchins and Edith H. Luchins, Revisiting Wertheimer’s Seminars, Volume 1: Values, Social Influence and Power, (Canbury, NJ: Associated University Press, Inc., 1978), 33-34.

8 Jacob, The Scientific Revolution, 97.

9 Peter Gay, The Enlightenment: The Science of Freedom, (New York: W.W. Norton & Co., 1969), 126.

10 Jackson J. Spielvogel, Western Civilization: Since 1500, 7th ed. (Belmont, CA: Thomas Wadsworth, 2009), 510.

11 John Locke, An Essay Concerning the True Original, Extent and End of Civil Government , sec. 87 (1696),  http://www.lonang.com/exlibris/locke/loc-207.htm (accessed 24 June, 2010)

12 Christopher W. Morris, Introduction to The Social Contract Theorists: Critical Essays on Hobbes, Locke, and Rousseau, (Lanham, MD: Rowman &Littlefield Publishers, Inc, 1999), ix-x.

13 David Hume, Of The Original Contract, (1748), www.constitution.org/dh/ origcont.htm  (accessed 24 June, 2010)

14 Jacob H. Hollander, “Adam Smith, 1776-1926”, The Journal of Political Economy, vol. 35(2) (April 1927): 61-62, http://www.jstor.org/stable/1823420 (accessed 24 June, 2010)

15 Gay, The Enlightenment, 378.

16 John A. Taylor, British Monarchy, English Church Establishment and Civil Liberty, (Westport, CT: Greenwood Press, 1996), 48.

17 Peter Burke, A Social History of Knowledge: from Gutenberg to Diderot, (Malden, MA: Blackwell Publishers, Inc., 2002), 166.

18 Gay, The Enlightenment, 374.

19 Ibid., 375 – 386

20 Ibid., 317

21 David Hume, An Enquiry Concerning Human Understanding, section VIII,  (1740)  http://faculty.uml.edu/whitley_kaufman/Introduction%20to%20Philosophy/hume.freewill.htm (accessed 24 June, 2010)

22 Gay, The Enlightenment, 167.

23 Ibid., 323.

24 David Hume, A Treatise of Human Nature, Introduction, (1740) http://www.gutenberg. org/files/4705/4705-h/4705-h.htm#2H_INTR (accessed 24 June, 2010)


David Hume and Skepticism

David Hume, according to the Stanford Encyclopedia of Philosophy, is the most important philosopher to ever write in the English language.  He was also deeply influenced by thinkers from Emmanuel Kant to Jeremy Bentham, Charles Darwin and Thomas Henry Huxley. (1)   Hume was one of the big three of British empiricism, the other two being John Locke and George Berkeley.   Hume was much better known and better paid as a historian than as a philosopher in his own time.(2)  But it is his philosophical writings that continue to influence thinkers even today.  Recently, Hume’s “Of Miracles” was quoted and cited on a skeptical podcast.(3)

Without a doubt, Hume followed Locke’s thoughts as to the nature of human knowledge.  In short, humans are born as “white paper,” and that paper is written on by experience. (4)  For Hume, there are only two kinds of ideas: ontological ones, such as one plus one equal two, or “matters of fact,” such as the sun will rise.  For Hume, the ontological ideas are self-evident since we can’t conceive of them any other way, but “matters of fact” are less sure since they may be falsified either through misperception of our senses or simply not be true.  However, he still believed that our sensory experience was much more valuable than the second-hand experiences of reading or hearing about a phenomenon. In short, seeing the sun rise is a more important and truer experience than just hearing a description of it.

For the Enlightenment, perhaps Hume’s most important work is the Enquiry Concerning Human Understanding, in which he asserted:  “Even Mathematics, Natural Philosophy, and Natural Religion, are in some measure dependent on the science of MAN; since they lie under the cognizance of men, and are judged of by their powers and faculties.”(5)  What that means is that man is subject to the same laws of nature as any other part of the world and also that the laws of nature are only manifested through human understanding.

Further, a chapter in the essay “On Miracles” supports the general skepticism of religion and atheism of his fellow philosophers.  In its most telling phrase: “no human testimony can have such force as to prove a miracle and make it a just foundation for any such system of religion.”(6) Hume, at one swipe, destroyed the basis for all Western Religious belief.   In conclusion, Hume took to their logical conclusion skepticism and empiricism, resulting in atheism.


1William Edward Morris, “David Hume”, The Stanford Encyclopedia of Philosophy,  ed. Edward N. Zalta, (Fall 2010 Edition) at http://plato.stanford.edu/entries/hume/  (accessed 13 September 2010)

2 John A. Taylor, British Monarchy, English Church Establishment and Civil Liberty, (Westport, CT: Greenwood Press, 1996), 48.

3 The Skeptics’ Guide 5X5 Oct 8 2008 at http://www.theskepticsguide.org/archive/ podcast.aspx?mid=2 (accessed 14 September 2010).

4 John Locke, An Essay Concerning Human Understanding Book II Chapter 2 (1690) at  http://www.gutenberg. org/files/4705/4705-h/4705-h.htm#2H_INTR (accessed 14 September 2010)

6David Hume, An Enquiry Concerning Human Understanding (1748), Section 10 http://www.gutenberg.org/dirs/etext06/8echu10h.htm#section10 (accessed 14 September 2010)

The Philosophy of David Hume

David Hume, was and is one of the most influence writers and philosophers in the English speaking world.  His philosophy profoundly influenced other philosophers from Kant to Bentham and also scientists from Charles Darwin to Thomas Huxley.

In his own time Hume was far better known as an historian than a philosopher, producing a wildly successful multivolume   history of Britain. However it is his philosophical writing that continues to affect thought even into the 21st century.  For example, Hume’s essay “Of Miracles” was quoted on a recent scientific podcast.

Hume, along with John Locke and George Berkeley were the “founders” of the school of philosophy known as British Empiricism.   For both Locke and Hume people were born “Tabula rasa” or blank slate and that slate was written on by life’s experiences.  For Hume these experiences could be of two kinds: ontological or “matters of fact”.

Ontological ideals are self-evident since they can, in short, be only the way that they are.  Simple math is ontological; two plus two will always equal four. No amount of misperception may change that simple basic ontology.

“Matters of fact” however are not self-evident and maybe false through either human sensory error or maybe simply untrue. For example, a “matter of fact” is the sun will rise. That may and most likely will happen, but it may not. Also humans not be able to perceive it correctly. However, Hume still believed that human sensory experience while potentially faulty was far superior to second hand knowledge such as merely reading or hearing about an experience. In short, for Hume, seeing a sunrise while potentially misperceived was far superior to reading about or merely hearing about a sunrise.

Hume’s most significant work is without a doubt: “The Enquiry Concerning Human Understanding”.  In this in work, he declares that man is the measure of all knowledge:  “Even, Mathematics, Natural Philosophy, and Natural Religion, are in some measure dependent on the science of MAN; since the lie under the cognizance of men, and are judged of by their powers and faculties.”  In that humans are controlled by the same “laws of nature” that apply any other parts of the universe, but also that those natural laws are only discoverable through human understanding.

Further, a section of “The Enquiry Concerning Human Understanding” titled “Of Miracles” supported general skepticism of religion and could be read as a support for atheism.  The essay’s most significant phrase is: “no human testimony can have such force as to prove a miracle and make it a just foundation for any such system of religion.” Hume, in this one short sentence managed to throw into doubt the basis for all religious belief.


Hume,  David, A Treatise of Human Nature, Introduction, (1740) http://www.gutenberg.org/files/4705/4705-h/4705-h.htm#2H_INTR

Hume, David, An Enquiry Concerning Human Understanding (1748), Section 10 http://www.gutenberg.org/dirs/etext06/ 8echu10h. htm#section10.

Morris, William Edward. “David Hume”, The Stanford Encyclopedia of Philosophy,  ed. Edward N. Zalta, (Fall 2010 Edition) at http://plato.stanford.edu/entries/hume/

Skeptics’ Guide 5X5, The Oct 8 2008 at http://www.theskepticsguide.org/archive/podcast.aspx?mid=2