Descartes in Ulm

After the conclusion of the Treaty of Ulm, the French ambassadors went to the Danube on July 6 and arrived in Vienna on July 20.

The Duke of Bavaria withdrew his troops from Swabia to lead them into Upper Austria to serve the Emperor.

But Descartes wanted to remain in Ulm to study the country.

Some German authors did not know the history of their country when they wrote that Descartes was sent to winter quarters in Ulm, immediately after the conclusion of the treaty, which they wrongly qualify as a “peace.”

It is enough to note two things to dismiss this idea:

1. The Bavarian troops, among whom Descartes had enlisted, never entered the city of Ulm and left the extremities of Swabia immediately after the treaty

2. It was then the height of summer.

Far from giving winter quarters to the troops, the Duke of Bavaria marched his own with all diligence along the Danube against the Protestants of Austria who had allied themselves with the discontented from Bohemia against Emperor Ferdinand; and the Marquis of Anspach, by a completely opposite march, advanced his own by great stages along the Rhine, to defend the Palatinate against the Marquis of Spinola, sent from the Low Countries with Spanish troops to assist the Emperor.

Therefore, no troops, whether Catholic or Protestant, remained in Swabia, much less in the city of Ulm, where Descartes did not intend to lead a soldier’s life during his stay there.

He formed acquaintances suitable for a gentleman, and he particularly sought the acquaintance of people who had a reputation for skill in philosophy and mathematics.

The principal of those he visited was a certain Mr. Johann Faulhaber, who received him with great civility and whose kindness gave him reason to frequent his company.

Faulhaber, having noted in more than one conversation that he was not ignorant of mathematics and that he spoke pertinently about it when the subject came up, one day took it upon himself to ask him if he had heard of the analysis of geometers.

The deliberate tone with which Mr. Descartes answered “yes” made him doubt the matter. Taking him for a young presumptuous person based on his hasty answer, he asked him with the intention of embarrassing him if he believed himself capable of solving a problem.

Descartes said “yes” and promised him the solution to the most difficult problems without hesitation.

Faulhaber, who saw in him only a young soldier, began to laugh; and to mock him, he quoted some verses from Plautus to let him know that he was taking him for a Gascon as brave as the glorious braggart in question in the comedy. Mr. Descartes, stung by such a disproportionate comparison and sensitive to the insult this German was making to him, took up the challenge.

Faulhaber, who particularly excelled in arithmetic and algebra, having published a book on it in the vernacular shortly before, first proposed some fairly common questions. Seeing that he did not hesitate in his answers, he proposed more difficult ones, which did not embarrass the respondent any more than those of the first kind. Faulhaber began to change his demeanor; and after having apologized for the inconsiderate manner in which he had treated him, he very civilly asked him to enter his study with him, to confer together more calmly for a few hours.

He put in his hands the German book he had just composed on algebra. This book contained only bare questions, but of the most abstract kind, without explanations. The author had done so with the intention of exercising the genius of German mathematicians, to whom they were proposed to encourage them to provide whatever solutions they could. The promptness and ease with which Descartes gave the solutions to those that caught his eye while flipping through the pages caused great astonishment to Faulhaber.

But he was much more surprised to hear him add at the same time the general rules and theorems that were to serve as the true solution to these kinds of questions and all the others of the same nature. This novelty made him reconsider; he was ingenious enough to admit his ignorance of most of the things that Mr. Descartes was showing him, and he eagerly asked for his friendship.

It happened at the same time that a mathematician from Nuremberg named Peter Roten published the solutions he had found to the questions proposed in Faulhaber’s book. Roten, to return the favor, added at the end of his answers other new questions without explanation and invited Faulhaber to solve them.

The latter, finding that the difficulty of these questions was extraordinary, communicated the matter to Mr. Descartes and asked him to join him in his work. Mr. Descartes could not refuse him this kindness. The success with which he helped him out of the difficulty finished convincing him that there were no difficulties beyond the powerful genius of this young man.

It is claimed that it was at the same time that Mr. Descartes discovered by means of a parabola the art of constructing in a general way all sorts of solid problems, reduced to an equation of three or four dimensions. This is what he explained long after in the third book of his geometry.

He remained in Swabia until the month of September, at the end of which he took the road to Bavaria to cross into Austria. His apparent plan was to see the court of Vienna and to rejoin the entourage of the French ambassadors, who were to cross into Hungary to confer with Prince Betlen Gabor on the means of a settlement with the Emperor.

This opinion does not suffer great difficulty if we assume with some authors that Mr. Descartes entirely renounced the profession of arms during his stay in Ulm when he learned that the Duke of Bavaria, despite the treaty made with the corresponding princes, was nevertheless marching his troops against the Elector Palatine in Bohemia. But if it is true that he was at the famous Battle of Prague, as other authors assert, it is credible that instead of following the ambassadors, he returned from the city of Vienna straight to the camp of the Duke of Bavaria.

This prince had already reduced all the rebellious Protestants of Austria to the obedience of the Emperor.

He had since entered Bohemia; and having joined his army with that of Count De Bucquoy, he had already restored to duty a number of cities and places when Mr. Descartes arrived near him.

He was not the only one of the young French gentlemen who was curious to see the end of this tragic scene that the new king of Bohemia, the Elector Palatine, was to perform. Several went there to learn the military profession, particularly under Count De Bucquoy. But Mr. Descartes, who had other views and who only sought to know the human race in all its catastrophes, was content to be a spectator of others.

The affairs of the Bohemians were going from bad to worse, not only because of the junction of the two imperial and Bavarian armies which formed a body of 50,000 men towards the south, but also because of the descent that the Elector of Saxony had just made with 20,000 men from the north.

This Elector, who had refused the crown of Bohemia as well as the Duke of Bavaria before it was presented to the Elector Palatine, had been charged by the Emperor with the execution of the imperial ban published against the rebels. He was moreover dissatisfied with the Elector Palatine, who had not deferred to his advice, nor to that of the assembly of Mühlhausen, concerning the renunciation of this crown which they had advised him. In a word, he was the leader of the Lutherans of the Augsburg Confession, who, like the Catholics, could not tolerate the Calvinists making themselves masters of a kingdom and three large provinces by way of usurpation.

He had already reduced all of Lusatia when the Duke of Bavaria and Count De Bucquoy, after having taken fourteen or fifteen Bohemian cities, took the road to Prague, because the already advanced and very harsh season did not allow them to linger longer forming sieges. On Saturday, the 7th of November, they found themselves within cannon range near the Bohemian army which had accompanied them on their march; and they approached the city of Prague at a distance of half a league. The next day, Sunday, the octave of All Saints’ Day, the Bohemian army, which had advanced a small quarter of a league from Prague, camped on a fairly elevated position. The plan of the Elector Palatine was none other than to remain on the defensive, because his troops, increased by ten thousand Hungarians that Betlen Gabor had sent him, were still much inferior to those of the Imperials.

The Duke of Bavaria, and Count De Bucquoy in a litter from a wound he had received the previous Wednesday, seeing the enemy camped so advantageously and so well determined to fight, held a council to deliberate whether to present battle. The opinions were to risk nothing, when the barefoot Carmelite friar who had brought the blessed sword to the Duke of Bavaria from the pope, entered the council as a man inspired and promised victory in a tone as assured as if he had had a word from God himself. So, after having sent to reconnoiter the avenues and passages by which they could attack and disengage as needed, the army was arranged in such a way that the Duke of Bavaria held the right wing with Baron De Tilly, his general field marshal; and Count De Bucquoy, seated all armed in his litter, held the left with Tieffembach, general field marshal of his troops. The reserve corps after the rear-guard was composed of Croats and Italians. But the army was without cannons, whereas that of the Bohemians had ten.

The Carmelite Father had placed himself at the head of the vanguard with the crucifix in his hand to encourage the soldiers. But it was charged so roughly by the Bohemians that the battalions and squadrons were broken at first despite the foresight of Baron De Tilly. Count De Bucquoy, seeing the disorder that the enemy artillery was causing among the Bavarians, who were beginning to falter on the left wing, got out of his litter, wounded and ill as he was; mounted a horse; disengaged Baron De Tilly; restored the courage of the soldiers; changed the order of the battalions; joined all the squadrons into one body; placed himself at their head; and seconded by the Duke of Bavaria who had passed to the right wing, he completely defeated the enemy; took the ten cannons, 135 ensigns, without counting the entire camp with all the baggage. The Elector Palatine with several lords of his party saved himself in Old Prague, and the very next night he left with his wife and children to retreat to Silesia. There were 5,000 men killed on the spot, 2,000 drowned in the Moldau river, and several taken prisoner. The two Catholic generals, who had lost only 400 men, advanced their infantry against the walls of the city in the evening. The inhabitants of the three cities did not dare to risk a siege. So, the very next day they opened the gates to the Duke of Bavaria and Count De Bucquoy, who after a solemn entry went to the Capuchins to sing the Te Deum.

Descartes followed the victorious everywhere.

We do not know if he had contributed to this victory.

But he had a part in it, always maintaining his quality of a volunteer soldier under the Duke of Bavaria.

After the entry of the victors, the gates of the 3 cities were kept closed for 6 days, to search for the principal authors of the rebellion.

They were granted only their lives. The Lutherans of the Augsburg Confession were maintained there as well as the Catholics, but the Picards or Picardites, that is to say the Calvinists, were deprived of the free exercise of their religion, and they were worked to be humiliated all the more because they had appeared more zealous than the others in the election of the Palatine.

The remaining Bohemian cities, forty in number on the side of the rebels, came to eagerly bring their keys. Only those of Tábor and Plzeň, where the bastard of Mansfeld commanded with strong garrisons, remained. Baron De Tilly was established to command in Prague with six thousand men.

The generals, seeing that no more enemies presented themselves to fight, withdrew with their troops, after the principal lords of the crown of Bohemia had sworn an oath of fidelity and obedience to the Emperor, in the hands of the Duke of Bavaria, who left Prague on the eighteenth day of December, to come and spend the rest of the winter in Munich. He brought back a part of his troops to Bavaria and left the other in the southern part of Bohemia, to take up winter quarters there.

The space of six weeks during which the imperial army stayed in Prague was more than sufficient for Mr. Descartes to search for and visit the skilled people in this city. The time that the other soldiers and officers used to enrich themselves from the rebels abandoned to their pillage was for him an occasion for greater leisure and freedom, to attend to more honest pleasures, which he found in the conversation of the curious and learned people of the place.

The memory of the famous Tycho Brahe was always alive there, and his reputation had been maintained until then in as flourishing a state as it was at the time of his death, through the care of his heirs, and particularly of his illustrious disciple Johannes Kepler, the Emperor’s mathematician. Mr. Descartes found nothing more pleasant during this stay than the conversation of those who informed him of the particularities of the life of this great astronomer, who had formerly come from Denmark to live in Prague with his entire family. If we believe some authors, he took sensible pleasure in hearing about his beautiful inventions and in seeing his great machines that his heirs allowed him to examine at his leisure.

These two circumstances reported by Mr. Borel will seem quite plausible to those who will be content to judge the fact by the sole curiosity of Mr. Descartes. But they will be found to be more than doubtful when they are examined against the truth of history.

It is difficult for Mr. Descartes to have been able to procure learned and curious conferences with Tycho’s children or relatives, if it is true that none remained then who were in a position to answer his curiosity or who were actually living in Prague. Tycho had left six children at his death who all presented themselves as heirs.

They took care to publish some of his posthumous works and to dedicate them in their name to the Emperors Rudolph and Ferdinand in 1602 and 1626.

But we learn from a Saxon mathematician named Wilhelmus Johannis that as early as the year sixteen hundred fifteen, after having made all possible inquiries in the city of Prague about Tycho Brahe’s sons and daughters, he had found no one who could give him news of them.

Would Mr. Descartes have been more fortunate in his research? There was then a son of Tycho’s richly provided for in Bohemia; but he lived in the Province. So, only Baron De Tengnagel, Tycho’s son-in-law, could have remained in Prague for Mr. Descartes to see on the sciences. Tengnagel was also a man of letters and a mathematician; but I doubt that, having remained faithful to Emperor Ferdinand during the troubles, he would have remained in Prague among the rebels.

It is even less certain that Mr. Descartes had the satisfaction of seeing Tycho’s machines and instruments. The sad fate of these machines almost does not allow us to believe it.

Tycho had them transported from Denmark to Prague and from Prague to the castle of Benach. He had them brought back to Prague afterwards in the Emperor’s palace, from where they were passed to the hotel of Curtz. After Tycho’s death, Emperor Rudolph, fearing that they might be alienated or put to bad use, wanted to have ownership of them for the price of twenty-two thousand gold crowns, which he paid to Tycho’s heirs.

He committed a paid guard to them, who kept this great treasure so well locked up in the hotel of Curtz that it was no longer possible for anyone to see it, whatever quality, whatever merit, and whatever recommendation one could bring for that.

It is to say everything that even Kepler, as privileged as he was on the part of the Emperor, on the part of Tycho, and on the side of his profession, complained bitterly of not having been more favored than another in this matter. These machines remained buried in this way until the troubles in Bohemia.

The army of the Elector Palatine, believing it was laying hands on a property that belonged to the House of Austria, plundered them as enemy spoils; broke a part of them; and converted another to completely different uses. The rest was so distracted that it has not been possible to know since what became of so many precious monuments. This desolation had occurred as early as the year sixteen hundred nineteen, so that Mr. Descartes, who only entered Prague in sixteen hundred twenty, could have seen these machines only by a miraculous adventure, for which we would ask for a different guarantor than Mr. Borel.

It is true that they managed to save the great celestial globe, which was of brass; but it was only by removing it from Prague, from where it was immediately taken to Neisse in Silesia, where it was put in deposit with the Jesuits. It was removed thirteen years later by Ulrik, son of Christian, king of Denmark, conducted to Copenhagen, and placed in the royal academy. It was therefore necessary to better concert the fiction concerning Mr. Descartes’s curiosity in Prague, to make it more plausible.

But to say more certain things about him, we will return to what happened in his mind at the end of the previous year.