Yasuhito Nakanishi: The Gregorian Calendar and Yukichi Fukuzawa

2023/02/15

In Vatican City, there is a building called La Torre Gregoriana (commonly known as the Tower of the Winds). This tower, which stands between the museum and the library, is known as the facility where the first observatory in the Vatican was established. In the 1570s, Pope Gregory XIII gathered astronomers in this newly built tower with the aim of reforming the calendar. The Julian calendar of the time had an error in the length of a year that was too significant for not only the Roman Catholic Church but also Protestants to ignore. In 1582, by bringing together the superior expertise of astronomers, the Pope finally succeeded in dramatically reducing that error. The new calendar bearing the Pope's name has far better accuracy than the Julian calendar, even just in terms of the number of leap years. The Tower of the Winds can truly be called the birthplace of the modern calendar, the "Gregorian calendar."

In fact, about a century earlier, astronomers had been gathered at the Vatican for the same purpose of calendar reform, and among them was the German Regiomontanus. This astronomer, who observed the movements of the heavens at an observatory he established in Nuremberg and even manufactured observation instruments, was also a printer who performed his own printing and publishing. Around 1473, shortly after the birth of movable type printing in the West, Regiomontanus opened a printing office. He published everything from the works of ancient mathematicians and astronomers such as Ptolemy, Euclid, and Archimedes to contemporary astronomical books.

Scholars like Regiomontanus, who edited, printed, and published books themselves, are called "scholar-printers." Not only astronomers but also Renaissance humanists strove to master movable type printing in order to deliver Greek and Roman classics and their own writings to people across time and space. The collection of materials actually left by Regiomontanus crossed time and space to reach the hands of Nicolaus Copernicus, where it was used for the announcement of the heliocentric theory.

The close cooperation between astronomy and printing/publishing continued after the Gregorian calendar reform. Tycho Brahe, known for his comet observations, built a printing house adjacent to his observatory to publish his research results. Johannes Kepler, who served as Tycho's assistant and inherited his observation data, not only performed proofreading and editing for the publication of his own books but also handled everything from fundraising and paper procurement to supervising the engraving of punch matrices and the casting of type. And, as one might expect, he also seems to have opened his own printing office. While deeply involved in movable type printing, Kepler developed Copernicus's heliocentric theory and established the three laws of planetary motion. Among the European astronomers who constructed the modern view of the universe and led the spread of the Gregorian calendar, there were a significant number of scholar-printers.

On the other hand, how was this Gregorian calendar received in Japan? It was adopted in 1872 (Meiji 5). It was an attempt to accelerate the civilization and enlightenment of the country by resetting the previous calendar (luni-solar calendar) that was influenced by the movement of the moon.

This was a year of intense upheaval toward modernization, including the proclamation of the school system and the opening of the railway. Among these, the transition to the Gregorian calendar (solar calendar) likely caused the most confusion. The calendar reform by the Meiji government was incredibly sudden. The reform was announced on November 9 and implemented on December 3; in other words, the preparation period from announcement to implementation was less than one month. Farmers who operated their agriculture according to the old calendar engaged in "anti-new calendar riots," and there were opposing factions within the government, leading to a growing momentum to scrap the calendar reform altogether. At such a time, Yukichi Fukuzawa addressed the public in his book "Kaireki-ben" (Discussion of the Calendar Reform), explaining the mindset needed for the introduction of the solar calendar. Published in conjunction with the calendar reform, it is also one of the earliest publications for Keio University.

Setting aside the government's methods, Fukuzawa explained to the public why the solar calendar was necessary using his characteristic easy-to-understand language. While describing the background of why the new calendar was needed, there is a passage where he harshly concludes, "Anyone who says they don't need the solar calendar is a complete fool." It was so clear and helpful that even pirated versions appeared. This shows how much Fukuzawa's opinion gained the support of the public. While touching upon the error with the Julian calendar mentioned earlier, he even explains how to read a clock face at the end of the book. Clocks, which are commonplace today, were rare to Japanese people at that time.

In Europe, it is thought that educated people gathered at the offices of scholar-printers to engage in active discussions while performing editing and proofreading work. The Keio University Press during Fukuzawa's time likely had a similar environment. Fukuzawa, who used the trade name "Fukuzawaya Yukichi," was an unmistakable publisher.

Based on his conviction to responsibly sell the books he wrote, Fukuzawa established the Keio University Press with an attached printing office on the Mita campus. From the publishing office, where intellectuals gathered from government offices and other universities in addition to those related to the Juku, enlightenment books such as "Gakumon no susume (An Encouragement of Learning)" were published, leading the world of opinion in the early Meiji period. Am I the only one who feels like calling Fukuzawa, who talked with everyone near the printing presses, a scholar-printer of Japan?