From German: Aviad Shtir, Philosophy and Science series edited by Yehuda Meltzer, Attic Books and Yediot Books
Chapter 1
Paris, October 29, 1675
Optimistic belief in progress, and restless journeys
It is not good to be absorbed all day in contemplation.
Thinking is harmful to health, metaphysician.
You better watch what's sizzling and gurgling down there in the muddy bottom.
Durs Greenbein, on the snow, or Descartes in Germany,
Frankfurt, 2003
the fly
From the ceiling, the housefly makes its way around the apartment, and by the way, it changes its flight path again and again, with sharp movements. His movements have not been very fast for a long time, the days have shortened, and the fly lands lazily on the windowsill. The cold paralyzes him, but when the stove starts to warm, he flies again in the small room, lit by torches and candles. There is another heat source near the window. On the table next to him are strewn the remains of food, a cup with coffee and sugar. The sweet food entices the fly to fly to the table. There the source of the dark heat begins to move. A hand raised to strike casts a shadow, and the insect flees with lightning speed. While the man with the hand processes approximately twenty frames per second, the fly notices two hundred images in the same period of time. In his eyes, the hand was moving very slowly - like in slow motion - but the disturbing insect had long since blossomed towards the stove. From there the tiny creature observes the warm and large shadow, which looks as if it is always glued to its chair, and from there it flies again from time to time to the sided sugar...
Coffee, some wine and plenty of sugar
At the table sits a very bent figure, tirelessly reading and writing, and occasionally swats away a pesky fly with her hand, which loves sugar just like her. Thus we can compare in our mind's eye Gottfried Wilhelm Leibniz, as he sat and worked, most likely, in the same place from noon without respite. In any case, it would not have been difficult for him to describe what was happening from the point of view of a fly, because according to his perception, the entire world is made of a multitude of perceptions of different actors, each of whom has his own point of view. The summer evenings, which were particularly dry in Paris that year, had already gradually passed, and the weather was getting colder. Without a musk oven, it was impossible to endure a whole day, most of which is spent sitting. Still, this is the preferred way of life for the scholar who comes from Saxony, a region that is today in the eastern part of Germany.
Leibniz is twenty-nine years old, of average height, he is a little thin and has brown hair. He describes himself as a fairly level-headed person, who is neither prone to impulsiveness nor to bitterness, his mind is quick to the extent that his senses are alert. But most of all he fears that the constant sitting for the purpose of studying and the lack of sufficient movement may one day bring him an untimely death. During the day he drinks coffee with sugar in it, but in the evening only a little wine, which he also likes to sweeten a little, to the delight of the flies. In France, where the Gregorian calendar applies, today is Tuesday, October 29, 1675. Leibniz lived in the Faubourg Saint-Germain, on the 220-meter straight Rue Grencier - in those days the street was still outside the city center.
On that dreary Tuesday at the end of October in Paris, Leibniz put on paper for the first time a sign that was going to fundamentally change mathematics. What today is considered an advanced study material in mathematics, and which in that day arose from his quill, is a simple sign that spectacularly encapsulates the knowledge of the best mathematicians of the 17th century, and will be developed by its inventor and become the key sign of a new mathematical method. The meaning is the sign ʃ, an elongated version of the letter s, a sign known today as an integral - a method with which you can calculate elegantly and present in a meaningful way and with the help of which you will calculate both the slope of curves and the area under the curve. October 29 of that year marks one of the peaks in Leibniz's many years of work in the field of infinitesimal mathematics. As will become clear in the coming weeks and months, the sign ʃ that he introduced will make a decisive contribution to the development of a new computational method, which operates through infinite tiny sizes and within the framework of an easy-to-understand formula mechanism. But let's not be too late.
The evening before that Tuesday, Leibniz apparently went to bed late again. as often happened. "Stays up late at night and gets up late," is how he reported himself. To work tirelessly into the depths of the night, while others are already asleep - that's what he's used to. For about a year now, he has been diligently working here at night, on the narrow and dim Parisian street, not far from the Luxembourg Gardens. But how did Leibniz end up in Paris?
The road from remote Saxony to here could not have been richer in adventures. He was born in Leipzig in 1646 in a family of academics - his mother was the daughter of a famous lawyer, his father a notary and university professor - and grew up in a period of intellectual and political upheaval. Large parts of central Europe were then cities of ruins. The Thirty Years' War (1618-1648), which sowed destruction everywhere, has already ended, but left behind a crumbling continent and a split Christianity, with almost no conciliatory current. Likewise, the unity of faith and reason threatened to tear apart the emerging new sciences, born of rationalism and empiricism. At the age of eight, in the home library, without help - his father had died two years earlier - the brilliant boy taught himself Greek, Latin and Hebrew, devouring book after book, and even learning some of them by heart.
At first it seemed that the gifted young man would follow in his father's footsteps; He studied philosophy and law in his hometown and then in Baltdorf near Nuremberg. But after he finished his doctorate and habilitation (a stage that is somewhat similar to today's post-doctorate and is still practiced in several countries), he gave up the professorship that was offered to him, and instead - since he was constantly looking for new knowledge to absorb it - he went on a journey. Without any practical plan, but with an interest in everything and everyone, he traveled first towards Holland, only to get stuck in Frankfurt, and then, in 1668, in Mainz. There he was able to be accepted into the service of the Prince-Elector and Archbishop Johann Philipp von Schönborn and to participate in a larger project of legal reform.
Already in Mainz, his typical way of working was revealed: jumping here and there between many and varied political, religious and scientific questions. As a child of the Thirty Years' War and the period after it, he sought to find ways to bring about reconciliation in a politically unstable Europe, to reunite Christianity, and to encourage progress in all human affairs and in all fields of culture. worldwide spread of the Christian faith founded on the threshold of reason; promoting the general welfare; Improving life through science and technology - all his life Leibniz would be committed to these ideals.
But how do you achieve all this? Leibniz needed a universal scientific view and many allies: scholars close to him in their outlook, and especially powerful supporters. And all this, if possible, in one of the largest cities in Europe. Leibniz therefore did not hesitate when the opportunity arose, in the spring of 1672, to travel on a diplomatic mission to Paris, and participate there in the effort to distance the French government from a war against the Netherlands and Germany. He developed a plan for the conquest of Egypt in a military operation by Louis XIV - not only so that the power-hungry king would avoid an attack towards the east, but also to strategically place France in a position that would allow it to advance to the treasures of India and Southeast Asia. For this Leibnitz even suggested digging a canal between the Mediterranean Sea and the Red Sea. However, the "Egyptian plan", which preceded the idea of the Suez Canal by many years but never reached the ears of the King of France, finally became unnecessary a short time later, when France did invade the Low Countries.
Nothing, Leibniz thought to himself; The main thing is that it is in Paris, which - along with London - is the science and culture center of Europe. Almost half a million people lived in the French capital at the time, and Leibniz found himself living in the heart of a modern metropolis. Countless carriages and carriages moved through the streets and boulevards. Even after dark the traffic did not stop. The streets were lit by oil lamps, which were relit every evening: Paris was the first volume in the world to have street lighting on a large scale.
Leibniz was electrified, and dived enthusiastically into the vortex of urban modernity. He was full of desire for action, and sought the proximity of the social and scientific elite - first and foremost the Academy of Sciences, where the best scientific minds worked and studied. He forged connections with several members of the Academy, and met, among other things, with the royal librarian Pierre de Carcavy, with Giovanni Domenico Cassini, who worked at the Paris Observatory, and was also invited to the discussion circles at the home of the well-known theologian and philosopher Antoine Arnault. Arnold). Here he even managed to come into contact with the powerful Minister of Economy and Trade Jean-Baptiste Colbert.
In Paris at that time, the philosophy of René Descartes was on everyone's lips. The followers of Descartes divided the world, in strict dualism, into matter and spirit, and they considered the animals to be mechanical automatons. They argued that non-human living beings, despite their complexity, are fundamentally no different from the mechanism of a clock or a water pump. In general, cultural and scientific Paris was enthusiastic about automata and machines, and their presence in everyday life grew more and more - whether in the form of automatic toys in the children's rooms of aristocratic families, whether in the siege engines of the army, whether as clocks with moving figures in the royal courts, or as hydraulic organs in the church. Fine mechanics experts worked to build robots that could be used. Plays performed by moving machines were put on the stage, and on Leibniz's street lived Alexandre de Rieux, Marquis of Surdiac, who was one of the followers and founders of the Theater of Machines.
Even Leibniz, who was about to investigate the legacy of Descartes in Paris, was fascinated by this world of automata, but unlike the Cartesians (followers of Descartes) he did not see nature and life as complex mechanical mechanisms. In his eyes, consciousness and the mind were in no way the exclusive property of humans - they are present in all of nature, albeit at different levels. This is what Leibniz meant when he said that the whole world has a soul. Even tiny creatures like fleas or flies are not just dull automatons, but have awareness and perception - even if in a very simple and basic way, and different from ours.
Today's neurobiologists agree with Leibniz: experiments with implanting electrodes show that houseflies have basic cognitive abilities and a primitive form of consciousness. Of course, Leibniz also felt that the flies were oppressive creatures, competing with him for his favorite sugar, but unlike the Cartesian philosophers, he did not see them as flying machines and nothing else.
More of the topic in Hayadan:
