Yasuhito Nakanishi: The Gregorian Calendar and Yukichi Fukuzawa

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 to aim for calendar reform. The Julian calendar of the time had an error in the length of a year that was too significant for even Protestants, let alone the Roman Catholic Church, 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 similarly been gathered in the Vatican aiming for calendar reform, and among them was the German Regiomontanus. This astronomer, who observed the movements of the heavens at an observatory established in Nuremberg and even manufactured observation instruments, was also a printer who performed printing and publishing himself. Around 1473, shortly after the birth of movable type printing in the West, Regiomontanus opened a printing office. He published everything from the books of ancient mathematicians and astronomers such as Ptolemy, Euclid, and Archimedes to contemporary astronomical texts.

Scholars like Regiomontanus, who personally edited, printed, and published books, are called "scholar-printers." Not only astronomers but also humanists of the Renaissance period 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 behind by Regiomontanus crossed time and space to reach the hands of Nicolaus Copernicus, where it would serve the publication of the heliocentric theory.

Even after the Gregorian calendar reform, the close cooperation between astronomy and printing/publishing continued. Tycho Brahe, known for his comet observations, established a printing plant alongside 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 punches and the casting of type. And, as one might expect, he also seems to have opened his own printing office. While being 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 far too 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 conducted agriculture according to the old calendar engaged in "anti-new calendar riots," and there were opposing factions within the government as well, leading to a growing momentum to abandon the calendar reform altogether. At such a time, Yukichi Fukuzawa addressed the public in his book "Kaireki-ben" (Explanation 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 sternly declares, "Anyone who says they don't need the solar calendar is a complete fool." It was so easy to understand and helpful that even pirated versions appeared. This shows how much Fukuzawa's opinions 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 around scholar-printers to perform editing and proofreading while engaging in active discussions. The Keio University Press of the time when Fukuzawa was present may have been in a similar environment. Fukuzawa, who held the trade name "Fukuzawaya Yukichi," was an unmistakable publisher.

Based on the conviction that he should take responsibility for selling 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 criticism in the early Meiji era. I am likely not the only one who feels tempted to call Fukuzawa, chatting with everyone near the printing press, a scholar-printer in Japan.