This is the second installment in my two-part series on philosophers. For this week, I chose a philosopher who better fits the description of a ‘historical character’.

Diogenes the Cynic was a Greek philosopher who lived in the fourth century BC. When he was a young man, he and his father were exiled from their home of Sinope for defacing currency. Diogenes traveled from there to Athens, where he took up a life of asceticism and became a notorious contrarian. He supposedly badgered Antisthenes, an ascetic student of Socrates and the founder of Cynicism, to be his mentor (though Antisthenes may have beaten him away with a staff the first time he asked).

Detail from Giulio Bonasone’s Diogenes and Antisthenes

According to Cynicism, the purpose of life was to achieve happiness by living simply, naturally, and virtuously, without pursuing wealth, power, or fame. In practice (as we will see with Diogenes), this often led to criticizing other people’s ways of life. That has resulted in the modern understanding that someone who is “cynical” is jaded and skeptical of others’ motivations.

Diogenes’s written works have been lost to history, but fortunately he believed in teaching through action, and tales of his philosophical stunts survive. Whether or not he learned from Antisthenes directly, Diogenes’s illustration of Cynicism through his ascetic lifestyle and shameless stunts ultimately made him the more famous of the two.

In Athens, Diogenes lived in a tub (basically a large ceramic jar, turned on its side). By putting his simple lifestyle on display, he hoped to demonstrate that the physical and social structures of the city were unnecessary; he found social etiquette and taboos just as unnatural and restrictive as attachment to superfluous possessions. As such, he lived without shame, flouting cultural conventions and begging for food on the street. He is also reputed to have destroyed his only wooden bowl upon seeing a boy drinking from the hollow of his hands, remarking “Fool that I am, to have been carrying superfluous luggage all this time!”

Diogenes at home

Diogenes also performed stunts that conveyed his criticisms more bluntly. He frequently strolled through the streets with a lantern, in broad daylight. When asked what he was doing, he would patiently explain that he was searching for an honest man. Unfortunately, his search was in vain.

Statue of Diogenes searching for an honest man

Many of his stunts directly targeted Plato. When Plato was applauded for defining man as a featherless biped, Diogenes plucked a chicken and brought it into Plato’s Academy, declaring “Behold! I’ve brought you a man.” Plato was thus forced to add something about “broad flat nails” to his definition. Diogenes also occasionally attended Plato’s lectures to distract those in attendance. At the root of all these antics was his unwillingness to accept Plato’s interpretations of Socrates; Socrates had also taught Antisthenes, whose ideas inspired Diogenes. So Diogenes and Plato can both attribute their ideas to Socrates (but Plato’s claim is more realistic).

Socrates and Plato in Raphael’s School of Athens

After many years, Diogenes ended up in Corinth. As the story goes, he was kidnapped by pirates while on a voyage to Aegina and sold as a slave to a Corinthian man. When the man, Xeniades, asked Diogenes what skills he had, Diogenes replied that he knew no trade but that of governing men (which apparently in ancient Greek sounded similar to “teaching values to people”) and that he wished to be sold to a man in need of a master. Xeniades was impressed and hired him to tutor his two children. Thus, even as a beggar-become-slave, Diogenes was the master.

Diogenes spent the rest of his life in Corinth, either continuing to work for Xeniades or as a free man (there are conflicting stories). He did not appear to resent his forced relocation from Athens; indeed, he was among the first to declare himself a “cosmopolitan”, a man not tethered to his country (or in the case of ancient Greece, a city-state), but rather a citizen of the world.

During his time in Corinth, Diogenes is said to have met with Alexander the Great. As the story goes,  Alexander sought him out in his tub (possibly he was freed and found a new “home” in Corinth) and offered him any gift he desired. Diogenes responded, “You cannot give me that which you are taking.” Then, as explanation, “You are standing in my sun.” Fortunately for Diogenes, Alexander seemed to retain his respect for the old Cynic, recognizing that Diogenes was expressing his contentment with the simplest and most natural life available (that’s my interpretation, anyway). Alexander reputedly said he would rather switch places with Diogenes than with anyone else.

Alexander the Great speaking with Diogenes

Diogenes retained his logic and wit to the very end. On the subject of his own burial, he suggested that his body be thrown over the city wall so wild beasts could feast on it – provided that he be given a stick with which to defend himself. When asked how he could use the stick if he lacked awareness, he responded: “If I lack awareness, why should I care what happens to me when I am dead?”

Ultimately, Diogenes did a great deal to promote the philosophy of Cynicism through his various antics, as well as utilizing parody and satire to great effect. In turn, Cynicism inspired the philosophy of Stoicism, which would be founded by Zeno of Citium in about 300 BC (not to be confused with Zeno of Elea, who came up with several famous paradoxes). Stoicism would go on to become a major philosophical school in Rome, with Emperor Marcus Aurelius being its most famous practitioner.

Despite his accomplishments and entertaining exploits, I can’t say I agree with Diogenes on everything. Some of his fabled interactions demonstrate just why social conventions are needed: apparently, he once spat in a man’s face because the man told him not to spit in his house. I appreciate Diogenes’s role as a disruptive force in ancient Greece, but I wouldn’t be especially eager to interact with him or to see a society implement all of his ideas.

This week, I’ll start a brief series on philosophers. Last semester I ignored the subtitle “Intriguing personages from Immanuel Kant to Napoleon, comandante,” but it’s a new year and I’ve resolved to stick to my promises. So this week’s blog will be about my favorite philosopher, Immanuel Kant.

Immanuel Kant, looking dramatic

Immanuel Kant was born in 1724 in Königsberg, Prussia, and would remain there for most of his life. His parents were strictly religious and Kant was schooled accordingly, reading a great number of Latin classics and learning to take the Bible literally. He expanded his horizons at the University of Königsberg, developing interests in math and physics as well as philosophy. After working as a private tutor for several years following his father’s death, he returned to the university and earned a Ph.D. in philosophy in 1755.

Kant’s first major ideas were actually in the realm of astronomy. Though he had developed interests in math and physics, he definitely did not have the proper scientific background to propose astronomical theories. Nevertheless, Kant posited that the Milky Way was just one of many galaxies, which formed from vast nebulae (this departed from Newton’s assertion that our Solar System was shaped by God). This multi-galaxy hypothesis sparked a debate among astronomers, and Kant was ultimately proved correct by Edwin Hubble in the 1920s. He also won the Berlin Academy Prize in 1754 for a discovery about Earth’s rotation.

The Milky Way, our home galaxy

While teaching at Königsberg in the early 1760s, Kant wrote a number of approachable and fairly popular philosophical tracts. Shortly after becoming a full professor in 1770, he stopped publishing original work and pondered his philosophy. One of the issues he contemplated was the debate between rationalism and empiricism. Rationalists held that truth could only be arrived at through reason; empiricists claimed that truth was only held in experience and observations of the natural world.

In 1771, Kant thanked a prominent empiricist, David Hume, for waking him from his “dogmatic slumber” (I used that line last year in a European History discussion… we were impersonating philosophers and I addressed it to Mr. Hume). This informed his eventual philosophy of transcendental idealism, which held that humans use reason and experience simultaneously to observe and understand the world around them.

This was one of the topics that appeared in his 1881 book, Critique of Pure Reason, which was a sharp departure from his earlier, more approachable works. The Critique was over 800 pages in the original German, and even fellow philosophers criticized it as convoluted. However, it contained many important ideas that he would attempt to clarify in later works; those ideas would make him one of the most important Enlightenment philosophers.

As I mentioned, one of Kant’s major ideas was transcendental idealism. This held that people impose categories of understanding on the world around them and that all knowledge depends on perception (like how rhetoric is needed to convey ideas; it is not as simple as there being a single truth). This philosophy can be thought of as a golden middle between rationalism and empiricism, both of which are rather extreme positions. As Kant described it, “Experience without theory is blind, but theory without experience is mere intellectual play.”

Though the book itself was not well-received, it was made famous when an Austrian philosopher, Karl Reinhold, published a series of public letters framing Kant and his Critique as the supreme authority on reason. This strengthened the credibility of Kant’s 1784 work, What Is Enlightenment?, which sought to define the Enlightenment and proclaimed its motto to be Sapere aude, or “Dare to know.”

Kant proposed several other intriguing ideas. The most famous is his theory of a binding moral law, which he named the categorical imperative. He stated that morality was based on rationality and that each person creates their own philosophy of how people should act. For example, if someone believes that cars should give bicyclists plenty of room when he’s riding his bike, he’ll uphold that expectation when he’s the one in the car (the moral law applies to everyone). People’s ideas about what the best system is may differ, but everyone forms these views by their own reasoning. As Kant put it, “Act that your principle of action might safely be made a law for the whole world.”

He also pioneered the idea that democratic governments and international cooperation would eventually lead to “perpetual peace”. He believed that this was the course history would eventually take, though many fellow philosophers still preferred monarchical government. Currently, I would comment that he may be right, but there remains a great deal of work to be done.

Despite his fundamentalist religious upbringing, Kant’s ultimate conclusion about God was that it was impossible to know whether he existed or not (which would make him an agnostic). However, Kant preferred to believe in God and in an afterlife, because he believed that humanity’s shared morality was indicative of the existence of God and strengthened by the presupposition of God’s existence. By publishing Religion Within the Limits of Reason Alone against King Frederick William II’s wishes in 1792, he earned a famous reprimand from the king. When he published a second edition in 1794, Kant infuriated the censor to the point that he ordered Kant to never again discuss religion publicly.

Personally, Kant was a frugal man. He devoted himself to his work, remained unmarried, and maintained a daily routine that the people of Königsberg set their clocks by (or so it is said). Though his health was not the best, he lived to nearly 80 years of age; the life expectancy at the time was less than 40.

Immanuel Kant statue in Kaliningrad (formerly Königsberg)

Maybe these things explain my fascination with Immanuel Kant, or perhaps it’s simply inexplicable. I’ll probably do just one more blog about a philosopher; if you have any suggestions about that or about future topics, feel free leave them in the comments.

As a student currently surveying several subjects for further study, I can personally appreciate the life story of the German polymath Gottfried Wilhelm von Leibniz. Though Leibniz is best known for his calculus notation and optimistic philosophy, he also excelled in several other fields. Despite spending much of his life working at jobs unbefitting of his intellectual capacity, Leibniz took every opportunity to expand his knowledge further. When he was supposed to be collecting historical information or conducting diplomatic missions, Leibniz spent his time having mathematical and philosophical discussions with fellow Enlightenment thinkers. He corresponded with over 600 scholars in total during his lifetime and went on to set up academies throughout Europe to encourage interdisciplinary study.

Gottfried Wilhelm von Leibniz pronounced “LIBE-nitz”

Gottfried Leibniz was born in Leipzig (in modern-day Germany) in 1646, during the final years of the destructive Thirty Years’ War. His father, a moral philosophy professor at the University of Leipzig, died when Leibniz was just six years old. However, Leibniz managed to learn large amounts of information from his father’s books and even taught himself Latin and Greek. During that time, he questioned Aristotle’s system of logic and adopted his mother’s Lutheranism.

Leibniz attended the University of Leipzig at age fourteen, where he focused primarily on philosophy. He gained interest in interdisciplinary work when a math professor discussed the potential application of mathematical proofs to fields such as logic and philosophy. Coincidentally, when I expressed my interest in math at a recent Penn State event, someone told me that advanced mathematics and philosophy can merge together. In Leibniz’s case, this revelation led to his idea for a comprehensive scheme of human knowledge.

Though he had built a scholarly reputation and completed his legal studies, the University of Leipzig refused Leibniz a doctorate in law In 1666. Disgruntled, he went to Altdorf and received his doctorate immediately upon submitting his dissertation De Casibus Perplexis. However, he turned down a position at Altdorf and went to Frankfurt for a few years to work for the German statesman Baron Johann Christian von Boyneburg.

Leibniz was a very literary man during his time there, thinking like a Renaissance humanist (such as Desiderius Erasmus). He developed a desire to reconcile the Christian churches, and to that end he often discussed religion with Boyneburg, who was Catholic, and wrote papers about their ideas. Boyneburg also introduced Leibniz to the Archbishop (and prince elector) of Mainz.

The Archbishop conceived of a plan to divert Louis XIV’s attention from the German lands: encourage him to send a religiously motivated expedition into Egypt. Leibniz saw in this a potential for uniting the churches and ultimately traveled to Paris in 1672 to carry out this diplomatic mission. However, this idea prompted far more philosophical and theological thought on the part of Leibniz than practical diplomatic results.

Before travelling to Paris, Leibniz developed the principle of sufficient reason (I know this is important because it came up in quiz bowl yesterday); it essentially states that there is a reason for everything – a cause or justification for the existence of everything that exists and a reason for every event that occurs. He published this and many more ideas in Demonstrationes Catholicae and Hypothesis Physica Nova, both of which held the existence of God as essential to their conclusions.

In Paris, Leibniz similarly focused on developing his ideas; he discussed church reunification with the theologian Antoine Arnauld and studied math and physics under Christiaan Huygens, rapidly increasing his expertise on those subjects. Leibniz was also to go on a diplomatic mission to London, so he made contact with scientists and mathematicians there and became a fellow at the Royal Society of London in 1673. Both Boyneburg and the Archbishop died without Leibniz having made any progress with the diplomatic assignments, and he returned to Paris after the Archbishop’s death.

One of Leibniz’s lengthy correspondences

While in Paris, Leibniz began to develop his calculus. He worked from a geometric perspective, thinking of derivatives as infinitesimal changes; though this way of thinking about calculus is no longer the preferred method, his notation is still used for both derivatives and integrals, as it is far better suited for advanced calculus than Isaac Newton’s.

Leibniz notation for an indefinite integral

Leibniz would have been happy to stay in Paris, but the Paris Academy of Arts and Sciences did not extend an invitation to him; apparently the French decided there were already too many foreigners in the Academy. Leibniz was thus forced to leave Paris, moving back to “Germany” to accept a post under the Duke of Hanover. His work was mundane, but he took on a number of ambitious side-projects and used those to study a great many topics.

For example, when he was commissioned to write a history of the Brunswick family, he spent years gathering and publishing archival information about the family; this entailed traveling to Vienna and Florence and talking with fellow scholars, but he never wrote the work that had been commissioned.

He also attempted to engineer a means of draining water from a mine in the Harz mountains using pumps powered by hydroelectric and wind power. These attempts repeatedly failed, but he made interesting geological discoveries in the process and became the first to posit that the Earth was originally molten. However, his pioneering of wind-harnessing technology is disputed.

Design of Leibniz’s plan in the Harz Mountains

During this time, Leibniz also made advances in mathematics, physics, philosophy, and theology. He published his theory of calculus in the mid-1680s, eliciting plagiarism allegations from Newton. Since Newton was the head of the Royal Society of London, he heavily influenced the Society’s investigation; unsurprisingly, it concluded that Leibniz had stolen his theory of calculus from Newton. Later analysis indicates that they invented calculus independently, building on the previous work of mathematicians such as Rene Descartes and Pierre Fermat.

Leibniz vs. Newton once again

In physics, Leibniz criticized Descartes’s mechanics and studied what are now known as potential energy, kinetic energy, and momentum. However, his perspective was too broad to have an immediate impact in the field. His major work was Dynamica, which was published in 1689.

He also conceived of many essential logical operators, which have been discovered in his working drafts. Though they were not published, his ideas regarding logic were the most important between Aristotle’s in Ancient Greece and George Boole’s in the 1800s.

Leibniz also rediscovered the use of matrices and binary, which were originally invented by Ancient Chinese mathematicians. His use of matrices to solve linear systems of equations paved the way for further work in linear algebra by Carl Friedrich Gauss in the early 1800s. Leibniz’s perfection of the binary number system was also vastly influential. He used it in his calculating machine, which was an improvement over Pascal’s rudimentary adding machine, and binary has been essential to all programming advances since then.

Obligatory ones and zeroes

In philosophy, Leibniz’s published work represented a fraction of his thinking on the subject and was rosier than his actual views, which were more logical and precise. Much of his own thinking dealt with a comprehensive system of human knowledge. Perhaps the romantic tone of his published work is best reflected in Discourse on Metaphysics (1686), in which he argues that the world was created in pre-determined harmony by a benevolent deity, a “best of all possible worlds”.

In Theodicy (1710), Leibniz revisited the dilemma of how bad things can happen in a world created by a benevolent God. This goes back to his principle of sufficient reason, which holds that there is a reason or cause for everything. Personally, I think that this is a faulty premise and led to his more outlandish conclusions, such as the “best of all possible worlds” claim; Voltaire satirized this in his 1759 novel Candide, with the protagonist insisting all is for the best as terrible things happen all around him.

Ever the optimist

Near the end of his life, Leibniz worked to set up academies in Vienna, Dresden, Berlin, and St. Petersburg, cementing his legacy defending multidisciplinary progress. He had the rare distinction of being on the leading edge of the varied disciplines of math, logic, physics, geology, philosophy, history, and theology all at once. Though he is primarily remembered as the target of Voltaire’s satire and as second fiddle to Newton, Leibniz did make important advancements in multiple fields and his life remains a testament to scholarly pursuits.