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Continental Rationalism: Descartes (1596-1650)


Thomas Hobbes (1588-1679): Life
Thomas Hobbes (1588-1679)
: Principal Works: Principal Works
Thomas Hobbes (1588-1679):
Ciccarelli Life Story
René Descartes (1596-1650): Life
René Descartes (1596-1650): Works
René Descartes (1596-1650):
Ciccarelli Creation: Back to Basics
René Descartes (1596-1650): Key Ideas
René Descartes (1596-1650): Influence
Baruch Spinoza (1632-1677): Life and Works
Gottfried Wilhelm Leibniz (1646-1716): Life
Gottfried Wilhelm Leibniz (1646-1716): Works
Gottfried Wilhelm Leibniz (1646-1716): Ciccarelli Life Story
Gottfried Wilhelm Leibniz (1646-1716): Ideas

Thomas Hobbes (1588-1679): Life

Click here to see a picture of Hobbes.

1588: Born in Malmesbury, England

1608: Received BA from Oxford

1610-26: Tutor to Cavendish (earl of Devonshire) family. Traveled to Continent, introduced to political and scientific circles, enjoyed access to excellent library.

1629: Second trip to Continent. Developed interest in geometry, deductive method.

1634-7: Third trip to Continent. Met Descartes, Gassendi; also Galileo whose theories of motion greatly impressed Hobbes.

1640-1: Political events in England escalated. Fled to France because of pro-royalist views. Continued philosophical, scientific writing. Wrote objections to Descartes.

1646-9: Tutored future Charles II in Paris. Illness. Met other royalists abroad. Execution of Charles I.

1651: Leviathan published

1652-8: Returned to England, submission to Commonwealth. Controversy with Bramhall over free will.

1660 onwards: Restoration. Attacked for "heretical" views of church, suspected of atheism. Many of Hobbes' ideas influential with Continental thinkers, however, including Spinoza, Leibniz

1679: Died at Cavendish estate in Derbyshire, England

Thomas Hobbes (1588-1679): Principal Works

1640: Elements of Law, Natural and Politique circulated in manuscript form. Published without Hobbes' consent as Humane Nature and De Corpore Politico in 1650.

1641: Objections to Descartes'Meditations, with Descartes' replies

1642: De Cive. Part two of Elements, expanded.

1651: Leviathan. Argued for absolute, undivided sovereignty; used concept of social contract.

1655: De Corpore. First part of planned trilogy.

1656: Questions Concerning Liberty, Necessity and Chance

1657-8: De Homine. Fragmentary 2nd part of trilogy.

1668: Behemoth. History of English Civil War. Published posthumously in 1682.

Thomas Hobbes (1588-1679): Ciccarelli Life Story

Early Biographical Sources

A chapter in John Aubrey's Brief Lives. John Aubrey was a contemporary. Hobbes also wrote a couple of autobiographies, one in verse form.

Early Life

1588: Born in Malmesbury, Wiltshire, England. The story is frequently told about the birth being premature, when Hobbes' mother heard of the approach of the Spanish Armada. "Fear and I were born twins." Thomas’s father was curate of a neighboring parish. He fled the area after he was involved in some kind of a brawl. Hobbes was raised by an uncle, a prosperous glover, later Alderman of Malmesbury.


c.1602-1608: Magdalen Hall, Oxford. Hobbes studied scholastic logic and physics. Hobbes in his autobiographies dismisses his education as "useless." He preferred reading accounts of world exploration, and geographical and astronomical maps. Astronomy remained a lifelong interest.

Employment, First trip to Continent

1610-15: Toured Continent with Cavendish family. After receiving the BA, Hobbes became tutor to William Cavendish, son of William, earl of Devonshire. This employment gave him an opportunity to travel around the Continent, meet influential people, and have access to a fine library. He was also introduced to political life. On these travels, Hobbes met Francis Bacon, and then Ben Jonson upon returning to London.

At this time, Hobbes turned to study of classics. He translated Thucydides (c.1628), and was impressed by the idea of history as instruction. He began to think about an application of this idea: making people aware of the dangers surrounding contemporary events in (Stuart) England, particularly of democracy and civil war.

The death of the first and second earls of Devonshire caused Hobbes to seek similar employment elsewhere briefly.

Further Travel, Encounter with Geometric Method

1629: Hobbes made a second trip to the Continent about this time and has a "philosophical awakening." In particular, he developed a great interest in geometry. Aubrey and Hobbes refer to Geneva, April-June 1630: Hobbes read Euclid's Elements in "a gentleman's library" and was hugely impressed with the deductive method of demonstration. (Malcolm notes that, although this seems to have been an important intellectual event, it was probably not his first encounter with geometry.) Thus Hobbes began to develop his method of analysis and his ideas of scientific method.

Resumes employment with Cavendish family, further travel, meets Descartes, Galileo

Hobbes continued to study mathematics and science (especially optics – cf. Spinoza, Descartes ) throughout the 30's, and began to outline his political philosophy. He was introduced to mathematicians and scientists in England and on the Continent through friends of the earl of Newcastle, especially Sir Charles Cavendish.

1634-37: Hobbes went on a third trip to the Continent as tutor to William, succeeding earl of Devonshire. He became a member of the intellectual circle around Marin Mersenne that included Descartes and Gassendi (who became Hobbes' good friend).

1636: Hobbes visited Galileo and was greatly excited by his theories of motion. Hobbes believed this could become the basis of an entire system, applicable even to civil and social matters, as well as to sensation, will, and emotion.

1637: Hobbes returned to England, which was in political turmoil.

Elements of Law

1640: Elements of Law, Natural and Political circulated in manuscript form. This was Hobbes’s first attempt to apply the deductive method and the "mechanistic psychology" to contemporary issues. He argued for undivided sovereignty.

1642: Hobbes expanded the second part and published it as De Cive.

1650: The entire work was published without Hobbes' consent in 2 parts: Human Nature and De Corpore Politico.

Flight to France, Exchange with Descartes

1640: Events in England escalate. Hobbbes fled to France, fearing for his own life given the distinctly pro-royalist views of Elements. Here he was again part of the circle around Mersenne. He there planned and began work on a trilogy that would examine the nature of physical bodies, of human behavior, and of citizenship.

Hobbes wrotes series of objections to Descartes' Meditations. Descartes' work on "mechanistic physics," perception (Discours de la MTthode, 1637), and optics was similar enough to that of Hobbes that he feels "preempted." They entered into a dispute about the priority of their discoveries. He also attacks Descartes' dualism and "lingering scholasticism."

1641: The objections and replies were published.

1642-46: Hobbes published a work on optics; he considered this one of his most important works.

1646: He briefly tutored the future Charles II in Paris, but fell seriously ill in 1647. After that he was drawn more into politics; many royalists had, like Hobbes, fled abroad.

At this time, Hobbes planned to write Leviathan. During this period he became known as one antagonistic to the Roman Catholic church (cf. the last section of Leviathan: "Kingdom of Darkness"), and was also suspected of atheism, as he will be throughout rest of life.

1649: Execution of Charles I.

Publication of Leviathan (1651) , Return to England (1652)

Leviathan: Hobbes wrote in favor of absolute, undivided sovereignty, and used the concept of social contract. Hobbes offended ecclesiastics (Catholic, Anglican, and Presbyterian) and universities. He was generally "vilified" in print, though some admired Hobbes' work, including members of his circle in Paris.

Return to England

1652: Hobbes returned to England. This was possible because his submission to the Commonwealth had been accepted. He would remain in London for most of the rest of his life.

Controversy with Bramhall, De Corpore, De Homine

1654-58: Hobbes engaged in controversy with Bramhall, Bishop of Derry over free will: Hobbes' psychological determinism vs. Bramhall's defense of free will.

1656: Hobbes published Questions Concerning Liberty, Necessity and Chance.

1655: De Corpore was published.

1657-8: De Homine (fragmentary).

These are basically the 1st and 2nd parts of the planned trilogy. There is no formal 3rd part except for earlier works like De Cive and Leviathan.

Anecdote about Hobbes and a beggar in the Strand

Aubrey tells the following story: One day, Hobbes while walking in the Strand, came upon an old, sick man begging. Hobbes, "beholding him with eyes of pity and compassion" gives him 6 pence. A "Divine" standing by, asks Hobbes if he would have done this if it hadn't been Christ's command. Hobbes says "Yes." The Divine asks why, and Hobbes replies: "Because I was in pain to consider the miserable condition of the old man; and now my alms, giving him some relief, doth also ease me." (Dick, ed., 157) [This seems telling, considering both his alleged atheism and his theories of motion and psychological determinism. All inclination, determination, including will, is ultimately based, for Hobbes, on aversion/appetite, which are motions.]

Restoration (1660), Condemnation of Leviathan, Heresy threat

Hobbes was pensioned by Charles II.

1666: House of Commons condemned Leviathan, but this was defeated in the House of Lords.

About this time it was rumored that some Anglican ecclesiastics want to have Hobbes tried for heresy. Hobbes takes this seriously enough that he writes a treatise on heresy, demonstrating why people should not be burned for it; he also destroys some of his manuscripts.

From 1665 on, Hobbes was also engaged in drawn-out controversy with two professors—of astronomy and geometry—at Oxford.

Dissemination of Hobbes' work on the Continent

1668: Hobbes' Latin works were published in Holland. De Cive was frequently reprinted on the Continent. Thus Hobbes' ideas became available to men like Spinoza and Leibniz. The latter was especially influenced by Hobbes in the late 1660's and early 1670's, and at one point writes to Hobbes: "I shall, God willing, always publicly declare that I know of no other writer who has philosophized as precisely, as clearly, and as eloquently as you have—no, not excepting Descartes with his superhuman intellect."

1668: Hobbes completed Behemoth (history of the Civil War); published posthumously, in 1682.

1672-6: Hobbes completed verse and prose autobiographies, translations of Odyssey and Iliad.

1679: Hobbes died at Hardwick, Derbyshire, at the estate of the Cavendish family.

1683: Hobbes' works were burned publicly at Oxford.

Sources for this Report

1) Sorell, Thomas, ed. Cambridge Companion to Hobbes . Cambridge: Cambridge University Press, 1996 (includes a biography by Noel Malcolm that checks primary sources against Aubrey, makes corrections).

2) Dick, Oliver Lawson, ed. Aubrey's Brief Lives. Edited from Original Manuscripts and with a Life of John Aubrey by Oliver Lawson Dick. With a foreward by Edmund Wilson. Ann Arbor: University of Michigan Press, 1949; Ann Arbor Paperback, 1962.

3) Encyclopedia Americana, International Edition. Volume 14. Grolier, Inc., 1982.

René Descartes (1596-1650): Life

Click here to see a picture of Descartes.

1596: Born in the town of La Haye, France; educated with Jesuits at the College of La Flèche

1616: Law degree from University of Poitiers (considerable family fortune made practicing law unnecessary for his survival)

1618: Joined army in Holland and traveled widely

1619 (Nov. 10): Dream of unified science of nature based on Mathematics; devoted life to philosophy; continued to travel widely

1629: Settled in Holland, where he was determined to write down his philosophical system

1649: Became a tutor in philosophy to Queen Christina of Sweden

1650: Caught pneumonia (apparently a result of overwork and the Stockholm climate—thank you Queen Christina!) and died. Click here to see a picture of Queen Christina.

René Descartes (1596-1650): Works

1628: Rules for the Direction of the Mind (unfinished; pub. in 1701)

1634: Le Monde (on universal causal mechanism, Copernican solar system; pub. delayed after Galileo crisis; eventually pub. in 1664)

1637: Discourse on Method (as a methodological preface to three treatises on scientific subjects: Geometry, Dioptric, Meteors)

1641: Meditations on First Philosophy (epistemology, metaphysics)

1644: Principles of Philosophy (philosophy and cosmology)

1649: The Passions of the Soul (the relation between mind and body)

Wrote very little on ethics or political philosophy

René Descartes (1596-1650): Ciccarelli Creation: Back to Basics

Mildred had her head stuck in the closet and was tossing items of clothing out into the room in a reckless fashion. Renée was struck in the face by a maroon and white striped cardigan as she came in.

"What on earth are you doing?"

"Rethinking my wardrobe," Mildred replied with a muffled voice, and then pulled her head out of the closet. "I have nothing to wear," she continued. "I hate my clothes. Nothing matches, nothing fits, nothing is ever appropriate."

Renée peered into the closet. "Where’d you get all this stuff, anyway?"

"I dunno. A lot of it I get on sale. But some of it has been there forever. I’ve just always had it," Mildred concluded vaguely.

"So what are you going to do?"

"Give it all to the thrift shop and start again." Mildred ripped several dresses off their hangars.

Renée stopped her friend. "Now don’t do that," she said. "Some of it may be useful. What you need to do is get back to basics."

"Basics?" Mildred emerged partially from the closet.

"Sure. The classics. Things that never go out of style. I bet you already have some right in here." Renée started to rummage through the closet.

"How do you know?" Mildred sounded doubtful.

"The point is, how will you know. You just will. You will recognize a classic article of clothing right away. Clear as clear."

"Well, I will if I can ever find it in this mess. I’ll have to pull it all out just to begin." And Mildred began to throw more things out into the room, adding to the general confusion.

"STOP!" Renée shouted.

This was so unlike her friend’s normal behavior that Mildred did just that.

"You need a plan. A method." Renée spoke again in her normal, quiet voice. "Let me make a suggestion."

"Well, I wish you would." Mildred pushed a strand of hair away from her eyes.

"First, don’t settle for anything but the basics. Don’t be tempted by a fabulous velvet-trimmed jacket that might be great if you only had the right slacks to go with it and the right occasion to wear it. Ask yourself if it is unquestionably a classic. If it isn’t. . ."

"I know!" Mildred cried. "Throw it out."

"NO!" Renée said. "Of course not. It may come in useful, or I might want it. Just put it over here, on the bed."

"And you say I will know, for sure?"

"No question about it."

"Well, I better get started right away, then," Mildred moved toward the closet again, quite excited about the new plan.


"What now?"

"That was only part of the plan," Renée explained. "The second part of the plan is to sort everything out in an organized way so you can see what you actually have and discover your classic items. Right now this place is such a mess, you’ll never find anything, and you’ll be discouraged before you start."

"Is that the whole plan?" Mildred asked humbly.

"No. Later on, maybe tomorrow, after you come up with your basic items--and there won’t be very many, believe me, just a few key pieces--then you can begin to put together a decent wardrobe again, perhaps using some of the stuff you put on the bed, and maybe purchasing some new things. Only this time you’ll start from your basics and go from there. That’s the reasonable way. No more buying things on impulse." She gave Mildred a severe look.

"Oh, it will be such a relief," Mildred sighed. "I’ve been so muddled about what to wear."

"Follow this plan," Renée said grandly, "and you’ll never be confused again. But you have to follow it exactly. No getting lazy, no deviations, no sentimental favorites. Be ruthless. "

When Renée returned several hours later, Mildred had made great progress. She had organized her clothing and accessories by season, style and type, and was now contemplating a corduroy jumper. She looked up at Renée excitedly.

"I did just what you said. So far, though, I haven’t discovered anything classic." And she nodded over at the bed where she had placed rejected candidates in various piles. Renée gave her an approving smile.

"I can’t wait until I do," Mildred continued. "I mean, this will really be a breakthrough!"

The minutes passed, until, finally, Mildred held up a navy wool blazer. The two women, who had been chatting animatedly, fell silent. Mildred looked over at Renée, a strange gleam in her eyes.

"This is it. I’ve found it. There’s just no question about it! This is a classic piece of clothing." Mildred was triumphant.

Renée congratulated Mildred. She was very positive about Mildred’s accomplishment. "This will be your key to a whole new world of fashion. The modern woman, well-dressed for any occasion. It will mean a whole new you."

Mildred looked happily at her blazer, but then voiced a new concern. "A whole new me. I hope you’re right. I just hope that when I come up with these three or four "classics," it’ll all hang together in a total look, an ensemble. I don’t want to represent Ms. mix and match. You know what I mean--the kind of person who never gets beyond separates."

But Renée never heard her. She had already left the room.

René Descartes (1596-1650): Key Ideas

1. Philosophic Goal: Certain Knowledge

Context: philosophical interest in skepticism stimulated by Protestant Reformation (via Montaigne) and scientific controversy

Goal: knowledge demands a foundation of absolute certainty; this premise is accepted throughout most of modern philosophy

Strategy: use Descartes’ rationalistic philosophical method

2. Procedure: Method of Doubt (cf. Discourse, Part II)

Descartes outlined a four-step procedure for achieving his philosophic goal.

  • Doubt all that can be doubted, including customary ways of thinking; then discover certain truth in "clear and distinct ideas"; uses "dream" argument and "tricky, evil demon" argument
  • Analyze every problem into its component parts
  • Synthesize reflection on various parts into a solution to problem
  • Systematize the procedure to achieve completeness and rigor

The supposed benefits of Descartes’ Method are:

  • Universal: applicable to every kind of rational inquiry
  • Produces discoveries: since it uncovers clear and distinct ideas
  • Practical: oriented to solving real problems by breaking them down into component pieces (analytic procedure) rather than to presenting solutions by building up a case (synthetic procedure—well illustrated by the synthetic procedure of Spinoza’s Ethics)

3. The Foundations of Knowledge

When the method of doubt is employed in search of certain foundations for knowledge (Meditations I), several key discoveries are made:

Cogito, ergo sum (Meditations II): "I think (even as I doubt), therefore I am"—and I also know my essence as a being lies in my ability to think.

Mind-Body Dualism: I can be certain that I (a thinking being) exist even while I am in doubt about everything else, including the reality of the physical world and my own body, so there must be a real distinction between my thinking essence and my body.

Types of Ideas: innate, invented, and learned.

Existence of God (Meditations III): My idea of "God" as an infinitely perfect being is clear and distinct, and so God must exist. But why is this idea clear and distinct when all the rest of my ideas of possible things are dubious? What stops me from doubting this idea of God?

Causes are always at least as real and perfect as their effects.

In particular, the cause of "idea of X" is at least as perfect as both "idea of X" (formally) and "X" itself (objectively).

But in my universal doubt, the thinking-I can cause "idea of X" for every possible X except X = "infinitely perfect being."

My idea of God is thus caused by something else, which would have to have much perfection as "God" has in my idea of God.

Therefore, God—the cause of "idea of God" in me—exists.

Existence of an External World: Descartes establishes the reality of the external world as a consequence of God’s reality and goodness. If our ideas about an external world were mistaken, the mistake could only be explained by supposing that God were misleading us. But this is impossible. Therefore, an external world exists.

René Descartes (1596-1650): Influence

1. Defines the modern philosophical-theological agenda

If Duns Scotus marks the turn from via antiqua to via moderna, then Descartes sets the modern philosophical agenda in several ways:

  • demand for certainty: only indubitable knowledge counts
  • rejection of external authority: they are irrelevant to knowledge
  • affirmation of reason: attain certainty by speculative reasoning (rationalism) or by reason analyzing experience (empiricism)
  • emphasis on the knowing subject: limits and value of knowledge have to be assessed with reference to the act of knowing

2. Natural Science

If Francis Bacon envisages knowledge of nature unfettered by authority, then Descartes finally cuts the ties with Aristotelian explanation. Matter is positive stuff rather than Aristotelian potential awaiting form, and can be studied for what it is. Aristotle’s soul and natural purposes are not needed to explain life and function. The human body is not enlivened by soul but only controlled by it as a machine operator controls a machine. Mathematics, for Descartes, is the language of nature (cf. Pythagoras).

Substance: that with a natural propensity to exist.

Living beings: complex natural machines.

Human being: an animal-machine controlled by a conscious soul.

3. Direct Theological Impact

  • View of God and nature sponsored deism ("watchmaker" God)
  • Sharpened question of how we know (or can know!) religiously
  • Began "turn to subject" that characterizes much modern theology

Baruch Spinoza (1632-1677): Life and Works

Click here to see a picture of Spinoza and here for a picture of his workroom.

All of Spinoza’s works were written in Latin. Only two were published during lifetime, one anonymously. There is a picture of his Tractatus manuscript here.

1662: Completes Short Treatise on God, Man, and His Well Being, Tractatus de Intellectus Emendatione

1663: Publishes an exposition on Descartes

1670: Tractatus Theologico-Politicus (published anonymously). Defends republican government, religious tolerance/liberty

1675: Completes Ethics, his best-known work (published in 1677)

Gottfried Wilhelm Leibniz (1646-1716): Life

Click here to see a picture of Leibniz.

1646: Born in Leipzig, Germany

1661: Studies law at University of Leipzig. Takes degree at University of Altdorf 1667.

1667-72: Employed as legal consultant by von Boineburg.

1672-76: Employed by Elector of Mainz; legal, diplomatic work, travel. Contacts with other scholars. Ongoing work in mathematics (developing calculus), physics, theology, invents mechanical calculator.

1676 onwards: Employed by Dukes of Brunswick-Lnneburg, in Hanover, for remainder of life, as librarian, historian, political, technical, diplomatic advisor. Continues own work in many areas: mathematics, science, mechanics, social reform, theology, philosophy, jurisprudence, organization of knowledge and research.

Travels widely, finds further employment at other German and Russian courts. Helps found several scientific academies, none immediately successful. Elected to Royal Society (1673), Academy of Sciences in Paris (1700). Wide reputation for philosophic, scientific work.

1698: Out of favor in Hanoverian Court, but continues in their employ. This Duke becomes King George I of England, 1714, but Leibniz left in Hanover. Illness, neglect; his political connections and religious ideas now found suspect by many.

1716: Dies in Hanover.

Gottfried Wilhelm Leibniz (1646-1716): Works

Click here to see Leibniz's Monadology manuscript.

Various essays in law, mathematics by 1672

1671: Hypothesis Physica Nova (theories of motion)

1675-6: philosophical notes: include ideas of harmony, perfection of God's creation. Pub. as Leibnitiana Elementa Philosophiae Arcanae de Summa Rerum (1913)

1684: Nova Methodus pro Maximis et Minimis (differential calculus)

c.1684: Meditationes de Cognitione, Veritate et Ideis (theory of knowledge)

1686: Discourse on Metaphysics; Brevis Demonstratio Erroris Memorabilis Cartesii et Aliorum Circa Legem Naturae (dynamics); Generales Inquisitiones (on propositions)

1694-5: Various articles dealing with scientific and philosophical problems: substance, force, mind/body relation, "pre-established harmony" and God's creation

1697: De Rerum Originatione (God as origin of things)

1698: De Ipsa Natura (Nature and theory of dynamics)

1710: ThTodicTe (theodicy)

1714: 2 articles that give overview of his philosophy: Principes de la Nature et de la GrGce FondTs en Raison and Monadologia

Gottfried Wilhelm Leibniz (1646-1716): Ciccarelli Life Story

Major sources for biographical information (not consulted for this report):

Guhrauer, G.E. Gottfried Wilhelm, Freiherr von Leibniz: Eine Biographie, 2 vols. Breslau, 1842. (Partially translated into English by J. Milton Mackie as Life of Godfrey William von Leibniz, 1845.)

Mnller, K. and Kr÷nert, G. Leben und Werk von G. W. Leibniz: Eine Chronik. Frankfurt am Main, 1969.

Totok, W., and Haase, C. Leibniz: Sein Leben, sein Wirken, seine Welt. 1966. (This "completes and corrects" Guhrauer, according to Encyclopedia Brittanica.)

Early Life, Education

1646: Born Leipzig.

His father was Friedrich Leibnntz (d. 1652), professor of moral philosophy, University of Leipzig. (Leibniz changed the spelling of name in his 20's.) His mother was Catherina Schmuck (d. 1664), Friedrich’s 3rd wife. They were Lutherans.

Started Nicolai School at age 7, but also self-taught in father's library. German literature, history, Latin, Greek, theology, logic. Showed interest in this last.

1661: to Leipzig University to study law. Also studies philosophy, rhetoric, mathematics, Latin, Greek, Hebrew. Encounters thought of Galileo, Bacon, Hobbes, Descartes.

Completes dissertation there but degree not granted because of his age. Finally submits at University of Altdorf, awarded law degree there (1667). Is offered professorship, but refuses, deciding on public career.

Political connections, research interests (1667-72):

First employed (legal work) by Baron von Boineburg (statesman), who introduces him to von Sch÷nborn, Elector (and Archbishop) of Mainz

Also involved in alchemical research (remains an interest throughout life), and other studies. Leibniz has various "projects":

- systematizing German law such that it can be deduced from a few basic principles

- the coordination and centralization of information and research: creating a master subject catalog, abstracting publications and registering new discoveries, founding new learned societies.

- Leibniz remained interested in this throughout his life, but except for subject catalog he was allowed to create for Boineburg, he was never allowed to pursue it at the various libraries in which he worked.

- Ultimately, he came to believe that all knowledge could be coordinated via a scientia universalis. His "thought alphabet" or universal characteristic and the calculus ratiocinator , the principle elements of this scheme, were ideas ignored in Leibniz' day and for the next 200 yrs, but are now recognized as noteworthy in the development of modern symbolic logic.

Carried on a massive correspondence with other intellectuals throughout his life (over 15,000 letters survive). He comments that "anyone who know me only by my publications does not know me at all" (Aiton, 9).

During this time, Leibniz, Boineburg, Archbishop involved in an attempt to "distract" Louis XIV's attention away from the H.R. Empire by proposing an expedition into/conquest of Egypt that would also be, ostensibly, an effort to reunify the Church (something else in which Leibniz was very interested). Boineburg sends Leibniz to Paris to present the scheme but he never gets a chance.

Paris 1672-76:

At death of Boineburg, enters service of Elector of Mainz

Meets with Arnauld, Malebranche, Huygens, et al. Access to unpublished works of Pascal and Descartes.

His main interest in this period was mathematics. He studied geometry under Huygens, made many important discoveries at this time; invented integral/differential calculus. Also developed his ideas on dynamics, contra Cartesian mechanics. Later there was a bitter dispute with Newton about priority in discovery of calculus.

1673: to London (diplomatic work for Elector). Scientific contacts there among members of Royal Society (elected to membership). Presented his mechanical calculator. [see attached picture]

Hanoverian court: 1676-86

Took position at court of John Frederick Duke of Brunswick-Lnneburg. Will remain in employ of this family till death.

- travels there via London and Amsterdam, visits Leeuwenhock and Spinoza.

- Ross (14) notes that he served in various capacities: librarian, political advisor, technological advisor, international correspondent. John Frederick is enthusiastic about some of his scholarly interests, as well as political/practical concerns.

Various intellectual pursuits during this time:

- Technological projects: from clocks to hydraulics and windmills (cf the Harz mines).

- Social/economic ideas: proposes educational reforms and foundation of new academies, tax reforms, and what Ross notes is a "primitive insurance scheme." Proposes a scheme for improvement of agriculture: notes the importance of "incentives" and so promotes rural music, dancing, and the introduction of "good beer into the country" (!) (Aiton, 86)

- Mathematics/Science: binary system, general topology, dynamics

- also continues philosophical writing, opposing many Cartesian ideas.

1679: Death of John Frederick, succession of Ernest Augustus I. The latter's dynastic ambitions cause him to set Leibniz to research/write a family history of the Guelfs. But Leibniz doesn't focus on this until after his mine project.

The Harz Mine Project (c. 1680-85)

- Assists as engineer. Has various ideas for water drainage but none fully successful.

- Meanwhile, procures urine from the latrines of the mines for the alchemical researches of an acquaintance who had produced phosphorous from urine. Experiments with phosphorous.

- important geological observations made during this work; Leibniz considered one of founders of geological science.

Philosophical Writings

- Publishes work on his theory of knowledge, writes the Discours de MTtaphysique (1686), writes logical treatise, publishes article outlining his theory of dynamics (1686).

Historical, Archival Research (1687-97)

- 1687-90: Leibniz travels widely for research, makes more scholarly contacts, is involved in diplomatic missions for the family, and continues discussions around the question of church unity.

- Always concerned to improve his position, he seeks part-time positions at other Brunswick family courts:

- 1691: Directs library at Wolfenbnttel (also uses for genealogical research)

- For rest of life spends fair amount of time travelling between work at Hanover, Brunswick, Wolfenbnttel, Celle.

- In the process of his genealogical research, Leibniz becomes interested in the idea of constructing a history of the earth from the earliest (prehistoric) times; he conceives of the study of languages as complementary to the study of history. He does write a geological history of the earth, Protogaea (pub. posthumously).

- In the course of all this work, he also collects and publishes materials connected with his interest in codification in jurisprudence.

- He is slow, however, to start the family history itself, causing ongoing irritation to his employers. Aiton comments that the family really wanted "a readable but authoritative little book that would impress" and help them with their dynastic schemes, not the massive historical projects Leibniz had in mind.


First uses term "monad" in letter of 1695, but most of concepts of this philosophy in place about 10 years earlier. Develops these in accordance with his other ideas on substance, space/time, harmony, etc. in series of notes, letters, articles during the period c. 1695-1706.

Diplomatic work, the academies (1698-1714)

Leibniz, helpful because of his connections with various courts, his legal training, and historical research, is involved in various diplomatic efforts, including establishing the electoral claims of the family. In 1698 Ernest Augustus dies. Georg Ludwig, who succeeds him, becomes elector of Hanover in 1692.

- relationship with Georg Ludwig is strained; he doesn't appreciate Leibniz' intellectual interests, and wants him to stay in Hanover and focus on his contracted work as historian and political advisor. Leibniz loses the position of relative privilege he enjoyed under preceding two Dukes. Spends as much time as possible away from the Hanoverian court, which is facilitated by the fact that he was employed, by 1712, at 5 different courts, each frequently complaining that he is not giving them their money's worth.

- Finds some solace in friendship with Princess Sophie (Ernest Augustus' wife) and her daughter Sophie Charlotte (Electress of Brandenburg).

Leibniz also involved in helping to establish Georg Louis' right of succession to the English throne.

1700: Elected to Academy of Sciences, Paris. Widely known by known for philosophic and scientific work. Much involved at this time with the role of the scientific academies. Helps to found several academies, none really successful during his lifetime; some became basis for successful institutions later.

1707-15: completes and publishes several volumes of the Guelf history. Last volume never completed.

1710: Publishes ThTodicTe. Results from discussions with Sophie Charlotte, and written to appeal to her, so less technical.

- Enc. Philos. article notes that this only "large book" by L published in his lifetime. Most of his work published in form of articles in journals.

1711-16: Several visits to Peter the Great of Russia, tries to found academy there. Given court appointment in science/mathematics.

Other Projects

  • promotion of silk production to assist German economy; eventually becomes important industry in Berlin.
  • proposes various civic projects for Berlin, Vienna (public health system, fire service, street lights, state bank)


One work that was incomplete at Leibniz death was his Discours sur la ThTologie Naturelle des Chinois.

- He had various relationships with Jesuit missionaries, especially Bouvet, and came to believe that the hexagrams of the I Ching were in agreement with his theory of binary arithmetic. Unfortunately he based his ideas on misinformation from Bouvet.

- Leibniz also promoted Protestant mission in China; he thought this would be productive both commercially, and through the exchange of knowledge.

Return to Hanover, death

1714: Writes Principes de la Nature et de la GrGce (pub. 1718) and La Monadologie (pub. 1720)

1714: Georg Ludwig becomes George I of England.

Leibniz returns to Hanover, works hard on the Guelf history, attempting to finish, but cannot complete before his death. These last years found him neglected at the court in Hanover while important courtiers had moved to England. Increasing illness. Also suspected of both political treachery because of his connections with non-Hanoverian states, and atheism or at least unorthodox ideas.

1716: Dies November 14.

No one attends funeral from the Hanoverian Court except the librarian (Eckhart) who took Leibniz' place, and the event is not noted by the academies in London or Berlin. One year later, a niece of Princess Sophie arranges to have an elegy read at the Paris Academy.


Ross comments that although Leibniz had some reputation for elegance during his earlier years at court, later he was at times ridiculed for his "old-fashioned, over-ornate clothes, his enormous black wig [see photo] and his half-baked schemes" (26-7).

He also portrays him as self-important and overly ambitious, obsessed by money, managing an "exceptionally high" salary by going back and forth between his appointments at various courts.

Sources for this Report

Aiton, E.J. Leibniz: A Biography. Bristol: Adam Hilger, Ltd., 1985. Aiton is a mathematician. Lots of mathematical details.

Ross, G. MacDonald. Leibniz. Oxford: Oxford University Press, 1984.

Encyclopedia Britannica, vol. 7, Micropedia, 1993.

Encyclopedia Americana, vol. 17, 1994.

Encyclopedia of Philosophy.

Gottfried Wilhelm Leibniz (1646-1716): Ideas

Monad: "a simple [without parts] substance which enters into composites" (Monadology 1)

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