Yokoi Shōnan and Yangming Philosophy: A Clarification of Misunderstandings

Abstract

In modern Japanese academia, the view has been proposed that Yokoi Shōnan “gained insights from Wang Yangming’s teachings and promoted practical learning 有得于王学而兴实学”, suggesting that his ideas on practical learning were influenced by Yangmingism. However, proponents of this theory have not provided strong evidence to prove a connection between Yokoi Shōnan’s practical thought and Yangmingism. From Yokoi Shōnan’s writings, his attitude toward Yangmingism was largely critical. In fact, the formation of Yokoi Shōnan’s ideas on practical thought underwent a rather complex process, shaped by his experiences with domain school reforms, interactions with various Japanese intellectuals during his period of study abroad, his understanding of Western culture, and discussions in practical learning study groups. Therefore, attributing his inclination toward practical thought solely to the influence of a single ideology would be overly simplistic.

1. Introduction

Yokoi Shōnan (1809–1869) was a thinker and reformer during Japan’s late Edo period. He advocated for a pragmatic academic style and, along with several like-minded individuals, formed the Practical Learning Party. Following the arrival of the black ships, he argued for the “opening of the country”, making him a pioneer of Japan’s modern transformation. With the implementation of the Meiji government’s westernization policies, Yokoi Shōnan, as one of the early proponents of introducing Western material civilization to Japan, saw his theories and achievements promoted within Japanese political and academic circles. Importantly, at the onset of modern Japanese research on Yokoi Shōnan, the academic community was experiencing a fervor for the study of Yangmingism, with views like “Yangmingism is the spiritual driving force behind the Meiji Restoration” gaining widespread popularity (Takase 1898, p. 264). Thus, when tracing the origins of Yokoi Shōnan’s practical learning thoughts, modern Japanese thinkers linked him to Yangmingism, proposing the notion that Yokoi Shōnan “derived his practical learning from Wang Yangming’s teachings”. Some even characterized him as a Yangming scholar (Inoue 1900, pp. 552–58). However, the issue lies in the fact that there are few references to Yangmingism in the writings left by Yokoi Shōnan, and there is no evidence to suggest that he systematically studied Yangmingism.

So, how did modern Japanese academia arrive at the conclusion that Yokoi Shōnan “derived his practical learning from Wang Yangming”? Is this assertion reasonable? What was Yokoi Shōnan’s actual attitude toward Yangmingism? If Yokoi Shōnan’s practical learning ideas do not originate from Yangmingism, what factors determined the direction of his thoughts?

Regarding Yokoi Shōnan’s practical learning thought, both Chinese and Japanese academia have produced some research findings (Wen 2023). However, the issue of the relationship between Yokoi Shōnan and Yangmingism mentioned above has not received widespread attention in academic circles. Therefore, this article will approach the popular notion in modern Japan that Yokoi Shōnan “derived his practical learning from Wang Yangming’s teachings” from the perspective of intellectual history, revealing the fallacies within this assertion. Based on this analysis, it will clarify Yokoi Shōnan’s true attitude toward Yangmingism and explore the ideological and practical background that led him to shift toward practical learning, with the aim of contributing to relevant academic research.

2. The Classification of Yokoi Shōnan’s School in Modern Japan and Its Fallacies

The claim that “Yokoi Shōnan gained practical learning from Wang Yangming’s teachings” was first proposed by the Japanese scholar Takase Takejirō in his book Yangming Studies in Japan. Later, Inoue Tetsujirō included Yokoi Shōnan in the lineage of Japanese Yangming studies in his book The Philosophy of the Japanese Yangming School. However, upon analyzing the relevant arguments of both Takase and Inoue, one finds clear logical flaws, and the influence of Yangming studies on Yokoi Shōnan is not as profound as they analyzed. Takase Takejirō wrote in Yangming Studies in Japan: “Figures like Yokoi Shōnan and Hashimoto Keigaku, although not Yangming scholars, gained practical learning from Yangming studies and loved reading the posthumous works of Banzan (Takase 1898, p. 264)”.

It is evident that although Takase Takejirō recognized that Yokoi Shōnan could not be classified as a Yangming scholar, he still believed that Shōnan was inspired by Yangming studies to pursue practical learning, with the evidence being that Yokoi Shōnan read the works of Kumazawa Banzan. However, Takase provided no other evidence to demonstrate the influence of Yangming studies on Yokoi Shōnan. While Kumazawa Banzan was indeed a member of the Japanese Yangming school, his thoughts and life had multiple facets, and his works contained more than just Yangming studies. Therefore, the mere fact that Yokoi Shōnan “loved reading Banzan’s posthumous works” only proves that he had a deep understanding of Kumazawa Banzan; it does not allow one to infer his attitude toward any specific idea of Banzan, nor can it be concluded that Yokoi Shōnan had a favorable view of Yangming studies.

Following Takase Takejirō, Inoue Tetsujirō also attempted to establish a connection between Yokoi Shōnan and Yangming thought. In his The Philosophy of the Japanese Yangming School, he analyzed two poems by Yokoi Shōnan (Yokoi 1938d, p. 876):

Ten Poems of Sentiment, No. 2 

I admire the teachings of Zhu Xi, A profound and deep academic lineage. Penetrating the myriad principles, All converge in this foundation of benevolence. Advancing or retreating, I leave to fate, Calmly nurturing the heart of the Way. With a sigh for the ages long past, How few are those who have passed on these teachings.

Ten Poems of Sentiment, No. 3 

How varied the changes in the game of Go, No two faces ever the same. Human affairs are much like this, Endless transformations, boundless indeed. How to respond to the infinite? With agility and mindfulness within. Truly, the learning of a gentleman, Lies in the efforts of investigation and understanding.

         感懷十首·其二

吾慕紫陽學，學脈淵源深。洞通萬殊理，一本會此仁。 進退任天命，從容養道心。歎息千秋久，傳習有幾人。

         感懷十首·其三

圍棋何其變，顏面一不同。人事率如此，變態誠無窮。 何以應無窮，靈活方寸中。果知君子學，總在格知功。

Inoue Tetsujirō pointed out that, “In the opening line of the second poem, there is the phrase ‘I admire the teachings of Zhu Xi.’ Based on this line, it seems that Shōnan followed Zhu Xi’s (Neo-Confucian) philosophy. However, in the third poem, he writes ‘How to respond to the infinite? With agility and mindfulness within. Truly, the learning of a gentleman lies in the efforts of investigation and understanding.’ From this, we can see that in practice, he actually endorsed the cultivation style of Yangming studies”(Inoue 1900, p. 553).

In the above quotation, Inoue Tetsujirō does not explain why the lines he cites represent “the cultivation style of Yangming studies”. I speculate that Inoue may have interpreted the word “方寸” [within the square inch”] as carrying a connotation of the xin (heart–mind) in the context of Wang Yangming’s xin xue (School of the Heart–Mind). After all, in the writings of Lu-Wang’s School of the Heart–Mind, “方寸” was also used to refer to the heart, as exemplified by Lu Jiuyuan’s statement: “The myriad things stand in array within the square inch, filling the heart, which pervades the universe; all is governed by principle” (Lu 1980, p. 423).

However, Zhu Xi also used “方寸” to refer to the heart, and he similarly emphasized the adjustment of the heart. In his Preface to the Annotations on the Doctrine of the Mean, Zhu Xi wrote: “The two [Editor’s note: referring to the human heart and the mind of the Way] are mixed within the square inch… one must discern the distinction between the two without confusion, and keep to the correctness of the original mind without deviation. If one works at this continuously, ensuring that the mind of the Way always governs the self and that the human heart always follows its commands, then the dangerous will become secure, the obscure will become clear, and in movement and stillness, there will be no error of excess or deficiency” (Zhu 2012b, p. 14). Zhu Xi believed that the human heart and the mind of the Way coexist within the square inch, and he advocated adjusting the two to achieve a state where the mind of the Way governs the human heart, thereby ensuring that one’s speech and actions are appropriate.

Yokoi Shōnan, in the quoted lines of his third poem, advocates responding to the boundless changes in human affairs with agility and mindfulness within the “square inch”. This bears similarities to Zhu Xi’s views, and therefore, it cannot be definitively concluded that the intellectual stance of Shōnan’s poem aligns with Yangming studies rather than Zhu Xi’s philosophy.

Even if we concede that the intellectual inclination of the third poem aligns with Yangming studies, it does not necessarily negate the content of the second poem. In fact, the opposite conclusion to Inoue’s interpretation could also logically stand: While Shōnan’s third poem seems to lean toward the Yangming school’s philosophy with lines like “How to respond to the infinite? With agility and mindfulness within”, the opening line of the second poem, “I admire the teachings of Zhu Xi”, reveals that Shōnan in fact adhered to Zhu Xi’s teachings. Moreover, while the third poem expresses a slight inclination towards emphasizing the heart, the second poem clearly demonstrates a reverence for Zhu Xi’s philosophy. This shows that Inoue Tetsujirō’s interpretation of the two poems is somewhat biased.

Another piece of evidence Inoue Tetsujirō uses to argue that Yokoi Shōnan was influenced by Yangming studies is the lecture notes Shōnan left behind when teaching the Analects, specifically the “Xue Er” chapter:

This chapter is the foundational teaching at the beginning of the text, making it a particularly important lecture. The term “cultivation of learning” can be found in the classics, and since ancient times, it has been the focus of sages and worthies from the earliest traditions. Regardless of what doctrine or lecture is taught, it must be understood from one’s own heart. Although Zhu Xi’s commentaries are detailed and thorough, if one only understands learning through his annotations, one becomes a slave to Zhu Xi and fails to grasp the true meaning of learning.

When mentioning later scholars, this refers to those who merely read and write essays. If we examine antiquity, this should never be the case. Since the time of Yao and Shun, or even during Confucius’ era, when were there as many books as today? And when have we ever heard of sages and worthies of the past encouraging people to merely focus on reading books? So, what did the ancients mean by learning? It all lies in the cultivation of our own hearts and minds. Expanding one’s innate sense of conscience, applying effort to the daily tasks and affairs of life—this is nothing other than learning.

In relationships between father and son, brothers, husband and wife, in serving one’s ruler or associating with friends, from loving one’s kin and caring for others to engaging with craftsmen, farmers, and merchants, as well as the mountains, rivers, plants, trees, birds, and beasts—understanding the principles of these things, reflecting on them in one’s reading, and studying the deeds and established methods of the ancients—this is how one learns the boundlessness of moral principles. By tirelessly pursuing this, the heart becomes more agile each day, and this is the cultivation of learning and practice. Yao and Shun also spent their lives cultivating themselves in this way. What else is there to the learning of the sages and worthies of old?

Later scholars, unaware of the practical efforts needed in daily life, only seek to understand principles through books. This is not the learning of the ancients but rather becoming a slave to the ancients. If you wish to learn Zhu Xi’s philosophy, you should reflect on what Zhu Xi himself learned. If you approach it only through Zhu Xi’s writings, you will become a slave to Zhu Xi.

Take poetry as an example: if you want to learn from Du Fu, you should examine what Du Fu learned, and trace it back to the Han, Wei, and Six Dynasties. Additionally, it is common for ordinary people to hear a sound argument, agree with it, and then treat it as merely a topic of conversation. Without putting it into practice, it remains no more than superficial knowledge, confined to mere words and hearing—this is a common failing among learners. Therefore, those with the will to study must strive to reach the ultimate principles, advancing a foot without retreating an inch—this is true cultivation. Do not forget this. And so on.

(Yokoi 1938b, pp. 931–32)

Inoue Tetsujirō, when analyzing the above lecture notes, argues that Shōnan’s discussion of cultivation within the “square inch” employs the heart–mind method of the Yaojiang 姚江 school (School of Heart–Mind) (Inoue 1900, pp. 553–54). Indeed, if we focus solely on the phrase “regardless of what doctrine or lecture, it must be understood from one’s own heart”, it is easy to read this as a rejection of external authority and the elevation of the individual heart–mind as the sole standard for judging right and wrong. This inevitably brings to mind Wang Yangming’s famous saying: “The key to learning lies in acquiring it through the heart. If something sought from the heart turns out to be wrong, even if Confucius himself said it, I would not dare to accept it as right—let alone something from those less than Confucius” (Wang 2015a, pp. 93–94). Similarly, the phrase “expand one’s conscience and apply effort to daily affairs” also bears a striking resemblance to Wang’s statement: “Extend the innate knowledge of my heart to all things” (Wang 2015b, pp. 55–56).

However, if we examine these phrases in the broader context of the entire lecture, we find that Shōnan is not discussing the “cultivation within the square inch”, as Inoue suggests, but rather addressing the method of learning. His recommended approach to learning does not stray from Zhu Xi’s broader framework of “investigating things to comprehend principles” (gewu qiongli 格物穷理). First, within the full context, Shōnan’s suggestion to “understand from one’s own heart” is not an emphasis on opposing external authority or denying any particular doctrine. Rather, it suggests that reading should not be limited to rote memorization or superficial recitation, but must be accompanied by genuine introspection and contemplation—this is precisely the reading method Zhu Xi advocated. Shōnan’s views align with Zhu Xi’s idea that “when reading, one must place the heart close to the text” and that “many learners fail to see the principles because their hearts are not engaged in their studies” (Zhu 1986, p. 177).

Furthermore, while it is undeniable that Shōnan’s phrase “expand one’s conscience and apply effort to daily affairs” echoes Wang Yangming’s “extend the innate knowledge of the heart to all things” in its wording, we must not forget that Zhu Xi also expressed similar views on the relationship between the heart and external things. Zhu Xi wrote: “The heart is the divine spirit of man; it holds all principles and responds to all matters” (Zhu 2012a, p. 349). This means that to determine whether Shōnan’s ideas are closer to Yangming studies or Zhu Xi’s philosophy, we cannot rely solely on superficial similarities in wording but must delve into the theoretical foundations behind these expressions.

Wang Yangming’s idea of “extending the innate knowledge of the heart to all things” is based on the premise of “the heart is principle”, that is, the unity of heart and principle. Wang stated that “The innate knowledge of my heart is what we call the heavenly principle. Extending the heavenly principle of the innate knowledge of my heart to all things, all things will thereby achieve their principle. Extending the innate knowledge of my heart is extending knowledge; ensuring all things achieve their principle is investigating things. This unites heart and principle as one” (Wang 2015b, p. 56). From Wang’s perspective, investigating things to extend knowledge involves a process where heavenly principle is inherently present in the human heart, and through investigating things, one brings the heavenly principle within the heart into all things.

In contrast, the process of studying and investigating principles described by Shōnan in the above lecture is the exact opposite. Shōnan emphasizes that one must “understand the principles of things and reflect on them in reading, study the deeds of the ancients, understand the boundlessness of moral principles, and pursue this tirelessly, so that the heart becomes increasingly agile—this is learning and cultivation”. He believes that principles must be internalized through learning, treating principle and heart as separate entities, which aligns closely with Zhu Xi’s approach of treating heart and principle as two distinct things. In other words, while Shōnan may use some Yangming terminology in his lecture, his overall views on the nature of principle and the method of study align much more with Zhu Xi’s philosophy.

Additionally, although Yokoi Shōnan criticized those scholars who were “slaves to Zhu Xi”, this does not mean he opposed Zhu Xi’s philosophy. The reason he criticized those scholars who “merely study books and seek principles” is precisely because they deviated from Zhu Xi’s teachings. Zhu Xi once said: “When a learner hears something, they must immediately put it into practice to truly grasp it. If they obtain a book, they must immediately read, reflect, and act upon it” (Zhu 1986, p. 183). He also said: “When reading, one must deeply experience it oneself; it should not merely be seen as words on a page… One cannot seek principles solely from the text but must reflect and apply them to one’s own life” (Zhu 1986, p. 181). In his lecture, Yokoi Shōnan called on scholars not to rely solely on extensive reading and memorization, but to apply their efforts to daily affairs, which aligns with Zhu Xi’s advocacy for “personal experience”. Moreover, Shōnan’s statement that “we should consider how Zhu Xi learned” clearly expresses his approval of Zhu Xi’s approach to scholarship.

At this point, all three pieces of evidence presented by Takase Bujirō and Inoue Tetsujirō to establish a connection between Yokoi Shōnan and Yangming’s philosophy have been laid out. As the previous analysis has shown, the evidence provided by Takase and Inoue is insufficient to prove that Shōnan’s advocacy for shigaku (practical learning) originated from Yangming’s thought, and the link that Takase Bujirō attempted to draw between Shōnan’s “pragmatic approach” and Yangming’s philosophy does not hold up. However, certain phrases with Yangming-like characteristics do occasionally appear in Shōnan’s poetry and writings, indicating that he had some understanding of Yangming’s ideas. So, what exactly was Yokoi Shōnan’s attitude toward Yangming’s philosophy, and how did his ideas on practical learning develop?

3. A Re-Examination of Yokoi Shōnan’s View on Yangming’s Philosophy

Yokoi Shōnan (1809–1869), originally named Yokoi Tokihiro, with the courtesy name Shisō and the pen name Shōnan, was a samurai from the Kumamoto Domain, a Confucian scholar, and a political thinker during the Meiji Restoration period. He was dedicated to advocating practical learning and improving social and political systems.

Born in the Kumamoto Castle town of the Higo Province (present-day Kumamoto Prefecture) into a middle-ranking samurai family, Yokoi Shōnan was intelligent from a young age. At the age of eight, he entered the domain’s school, the Jishūkan, for his education. Initially trained in Zhu Xi’s Neo-Confucianism, he gradually shifted towards practical learning in the early 1830s. In 1839, he traveled to Edo (modern Tokyo) for further study, where he met influential intellectuals of the time and engaged in extensive academic exchanges. However, due to conflicts with certain retainers within his domain, he was punished and sent back to Kumamoto, where he was placed under house arrest for a period.

In 1843, Yokoi returned to Kumamoto and established his private school, “Shōnan-dō”, which attracted many disciples. In 1849, his teachings reached the Fukui Domain, where they garnered the attention of the local nobility. He was invited to become a political advisor to the Fukui Domain, participating in local political reforms and cultural education initiatives. However, Yokoi Shōnan’s political career was far from smooth. He became embroiled in the political struggles between the Fukui and Kumamoto domains and had intense conflicts with conservatives due to his reformist views. In 1861, he was temporarily dismissed by the Kumamoto Domain due to an incident known as the “loss of samurai spirit”, and became a ronin (masterless samurai).

Afterward, Yokoi continued to engage in political activities, strongly advocating for national reforms and supporting the reformist faction. He called for the restructuring of the shogunate and the overthrow of the corrupt political system. In January 1869, Yokoi Shōnan was assassinated in Kyoto by a group of conservative samurai. Due to his support for the opening of Japan and establishing diplomatic relations with the West, some radical opponents accused him of trying to spread Christianity and saw him as a traitor who had deviated from traditional Japanese values.

Based on academic research on Yokoi Shōnan’s life, there is no evidence of him specifically studying under scholars of the Yangming School, nor was there a transmission of the Yangming School in his home domain of Higo during the 19th century. The most well-known Yangming scholar in the history of Higo Domain was Kitajima Setsuzan (1636–1697), who, as a retainer with a stipend of 400 koku, was forced into exile along with more than 20 others in 1669, when the domain banned the study of Yangming philosophy. This incident, known as the “Exile of the Heart Study Faction”, marked the decline of the Yangming School in Higo, preventing Shōnan from receiving an education in this school of thought within the domain (Mutō 1911, p. 292). Yokoi Shōnan entered the Higo Domain School, Jishūkan, at the age of 8 and became the dormitory head at 29. At the age of 31, he was ordered by the domain lord to study in Edo, so his formative years were largely shaped by the education provided at Jishūkan (Yamasaki 2006, pp. 9–27). Jishūkan was established in 1754, and its first professor, Akiyama Gyokuzan (1702–1763), was deeply influenced by the Sorai School. According to modern Japanese intellectual history, Sorai’s school split into two branches—one focusing on literature and the other on Confucian classics. Akiyama Gyokuzan followed the literary tradition, and Yokoi Shōnan regarded Akiyama as a scholar primarily devoted to literary studies (Motoda 1969, p. 21).

The second proJishūkan, Yabu Kōzan (1735–1802), was a follower of the Cheng–Zhu school (Neo-Confucianism), which opposed Sorai’s literary approach and emphasized the study of Confucian classics. Shōnan criticized Yabu Kōzan, stating that he “lacked talent for governance” (Mutō 1911, p. 179). The third professor, Takamoto Shimei (1738–1813), was a disciple of Yabu and had knowledge of kokugaku (National Learning) and Shinto, but Shōnan dismissed him and later professors as merely repeating their predecessors’ teachings without innovation (Motoda 1969, p. 21). Modern Japanese scholars also believe that Takamoto’s scholarship reflected the tendency of the Higo Domain during the Kansei era to flatter the official learning of the bakufu (Imanaka 1969).

The fourth professor, Karashima Shioi, became an assistant professor in 1804, and later served as the main professor from 1821 to 1839. Yokoi Shōnan entered Jishūkan in 1816, so Karashima’s influence on him was significant. However, Karashima’s academic style differed greatly from Shōnan’s. Karashima was known for his ability to memorize texts, which clashed with Shōnan’s opposition to rote learning (Mutō 1911, p. 291). Furthermore, Karashima disapproved of the practical thought Shōnan later advocated, criticizing those who adorned themselves with “practical learning” and engaged in superficial debates to gain short-term satisfaction (Karashima 1911, p. 288).

Through this review of Jishūkan’s history, two pieces of information can be obtained. First, the professors of the Jishūkan in successive generations either belonged to the Sorai school or the Zhu Xi school, and Yangming philosophy was never the mainstream in the educational curriculum of the domain school; second, although Shōnan was a standout student and was appointed dormitory head, he was critical of the academic styles of the Jishūkan professors, particularly Karashima Shioi. This academic divergence was a crucial factor in Shōnan’s eventual turn towards practical studies.

In March of Tenpō 10 (1839), Yokoi Shōnan embarked on his study trip to Edo. During this journey, Shōnan visited Zhu Xi scholars from the Hayashi school, such as Satō Issai and Matsuzaki Kyōdō, and he also became acquainted with Fujita Tōko of the Mito school. Shōnan and Tōko resonated with each other on the point of “focusing on practical matters” (Yokoi 1938g, pp. 899–900). In December of the same year, Yokoi Shōnan, who had been in Edo for less than a year, was invited by Fujita Tōko to attend a banquet. After the banquet, Shōnan composed a long seven-character poem on governing the country while intoxicated. News of this incident reached the Higo Domain’s Edo residence, where officials believed that Shōnan’s drunken behavior was inappropriate and could potentially reveal domain secrets. As a result, he was ordered to immediately return to his domain.

In December of the following year, senior officials in Higo discussed the matter and officially decided to impose a 70-day confinement as punishment for Shōnan (Yamasaki 1938, pp. 62–90). According to Motoda Nagafuku, during this 70-day period, Shōnan devoted himself to the study of Yangming philosophy, and it was during this time that his attitude toward Yangming’s teachings was solidified. Motoda wrote, “At that time, after Yokoi returned from Edo and was punished for his drunken mistake, he was confined for 70 days, during which he shut himself away to read. At first, he read Yangming’s books and immediately saw through the flaws in that philosophy. Then he read the works of Cheng and Zhu and came to believe that the pure and true Way of the sages was indeed found there” (Motoda 1969, p. 26).

This indicatenan’s focused study of Yangming philosophy lasted no more than 70 days, and from the very beginning of his engagement with it, he held a negative view of this school of thought. After the 70-day confinement ended, Shōnan, together with his associates Nagaoka Mononobe, Motoda Nagafuku, Ogi Masakuni, and Shimotsu Yasuka, formed a reading group advocating practical studies. According to Motoda, Yokoi Shōnan was the main proponent of the group. When the group was first formed, Shōnan proposed to his peers, “Our study of the classics is insufficient. Why not meet with the senior scholars to discuss the classics together?” Thus, they invited a senior scholar to read The Reflections on Things at Hand, and this marked the beginning of the gatherings between Nagaoka, Shimotsu, Ogi, and myself, which gave rise to practical studies (Motoda 1969, p. 27).

If we consider the establishment of this practical studies reading group as a symbol of Shōnan’s formulation of his practical thought, we will also notice two other intellectual events that occurred around the same time: first, Shōnan’s realization of the flaws in Yangming philosophy, and second, his proposal to make The Reflections on Things at Hand the first classic that the reading group would study. Since The Reflections on Things at Hand is a collection of scholarly discourses by Zhou Dunyi, Zhang Zai, and the Cheng brothers, compiled by Zhu Xi, its publication marked the completion of Zhu Xi’s construction of the Daoxue (Neo-Confucian) system. The book was later regarded as a cornerstone text by scholars of Cheng–Zhu Neo-Confucianism.

Shōnan’s negative assessment of Yangming philosophy and his choice of The Reflections on Things at Hand as the reading material for the practical studies group both indicate that he sought to find support for his practical thought within the orthodox Cheng–Zhu school. Yangming philosophy was not the driving force behind the formation of his practical ideas.

From the surviving manuscripts, it is evident that after the establishment of the practical studies reading group, Yokoi Shōnan never explicitly expressed admiration for Yangming philosophy, but he did criticize Yangming and his teachings. On 10 August 1849, Shōnan wrote in a letter to Honjo Ichirō: “Since Zhu Xi’s time, while the scholars of the Song and Yuan dynasties may lack grand aspirations, they generally adhere to the teachings of their masters and do not suffer from the maladies of fragmentation. However, the scholars of the Ming and Qing dynasties are muddle-headed, misunderstanding the teachings of investigation and extension. They merely read their books and discuss their meanings, thinking this is the essence of learning, which is a shallow habit stemming from the Yongle Dadian [a reference to the Encyclopedia], leading to the useless scholarship of common Confucians. Wang Yangming recognized the futility of these common Confucians and believed he understood Zhu Xi’s teachings on investigation and extension. He advocated the theory of innate knowledge, setting up the banner of a distinct and quiet Chan heresy… Yangming’s views are not even worthy of discussion” (Yokoi 1938c, p. 129).

From this, it is clear that Shōnan opposed the misunderstanding of Zhu Xi’s original intent by later common Confucians, and he also did not agree with Yangming philosophy, which had fallen into quietism as a correction to later Confucians’ biases. As some scholars have noted, what Shōnan sought to master was neither Yangming philosophy nor Sorai philosophy, nor the degenerate form of Zhu Xi’s teachings that had been criticized by Yangming and Sorai, but rather the authentic teachings of Zhu Xi before their degeneration (Matsuura 2000, p. 66). This interpretation aligns with the conclusions drawn from the earlier analysis of the lecture notes on the Xue Er chapter.

At this point, we can basically conclude that the background for Yokoi Shōnan’s proposal of practical studies is not as Takase Takesaburō suggested, that it was “derived from Wang Yangming’s teachings leading to the rise of practical studies”. So why did scholars like Takase Takesaburō and Inoue Tetsujiro misunderstand Shōnan’s affiliation? Inoue Tetsujirō’s incorrect classification of Yokoi Shōnan’s school may have been due to Inoue’s eagerness to use Western philosophical principles to construct a philosophical system for Japan. Because of time constraints, he did not carefully organize many aspects. Inoue’s trilogy began to take shape after his studies in Germany, where he sought to use Western philosophical principles to analyze Japan’s traditional philosophy and then build a philosophical lineage capable of standing alongside the West. At the same time, Inoue believed that moral decay had taken place in Japan, and he was eager to use ancient traditional philosophy to rebuild national morality, which was a lifelong endeavor. Overall, the main reason for Inoue’s misclassification of Yokoi Shōnan is that he was too hasty and did not carefully examine the details. Of course, if the Yangming school had fewer adherents, he might have forcibly included Yokoi Shōnan in it.

4. The Practical Incentives Behind Yokoi Shōnan’s Philosophy of Practical Studies

Through the analysis above, we have clarified Yokoi Shōnan’s attitude toward Yangming philosophy and demonstrated that the formation of his philosophy of practical studies has no direct connection to it. So, what were the incentives behind Yokoi Shōnan’s philosophy of practical studies? Aside from the notion that it arose from “gaining from Wang studies”, post-World War II research has largely focused on the “Practical Studies Reading Group” organized by Yokoi Shōnan, examining the books discussed in the group, and consequently noting the influence of Japanese Confucian scholar Ōtsuka Taira and Korean Confucian scholar Yi Toi-kyu on him (Hiraishi 2009; Imanaka 1969). Since the establishment of the “Practical Studies Reading Group” marks a crucial event in the formation of Yokoi Shōnan’s philosophy, it is certainly reasonable for scholars to analyze the origins of his philosophy through this event. However, looking at his life, it becomes clear that the formation of Yokoi Shōnan’s philosophy of practical studies was not an overnight process, and its sources were not limited to the content discussed in the reading group; instead, they were closely related to his experiences of the times and his understanding of the outside world.

The first factor determining Yokoi Shōnan’s orientation towards practical studies was his learning experience at the domain school, Jishūkan. From his early years, Yokoi Shōnan studied at Jishūkan, so the educational content and situation at Jishūkan formed the initial source of his philosophy of practical studies. Historical records indicate that at the beginning of Jishūkan’s establishment, the number of students exceeded a thousand, but the actual teaching results were unsatisfactory. Nakayama Mokuzai, who served as the head of Jishūkan, wrote in 1784 about the problems of the domain school education being detached from the practical needs of state governance in his work “Examination of Education Policy”: “School education of children is to nurture talents for the service of the state… Although the school has been established for more than thirty years and some talents have emerged, they cannot serve the state. There are not many who are proficient in economic techniques or knowledgeable about the national system. There are thousands of people who can write poetry and essays, and read extensively about foreign and domestic affairs. However, there are none who discuss the principles of governance, understand the political system, or are familiar with contemporary affairs” (Kumamoto-ken Kyōikukai 1931, pp. 115–16). The issues mentioned above remained unresolved during Yokoi Shōnan’s time at Jishūkan and became even more serious. According to Gen Yōbu, who entered Jishūkan in August of the eighth year of the Tenpō era (1836), students were admitted based on personal application without assessing their qualifications; most were impoverished individuals who could not support themselves, and the number was only a little over ten. To improve the academic atmosphere of the domain school, the Kumamoto Domain lord, Hosokawa Zaiho, appointed Nagaoka Monitor as the “Minister of Civil and Military Arts” in July of the seventh year of the Tenpō era (1836) to initiate the first reform of Jishūkan. Just six months later, Yokoi Shōnan was appointed as the “Dormitory Chief” of Jishūkan, becoming a key figure in coordinating and promoting this reform.

According to historical records of the Kumamoto Domain, Nagaoka Monitor was a proactive advocate and practitioner of the philosophy of practical studies. He “often worried about the declining national strength and unpredictable foreign threats, contemplating ways to uplift the morale of the people and revive customs, seeking to change the habits of empty rhetoric and superficiality. He vigorously took the lead in this effort, dedicated himself to practical studies, practicing military drills by day and earnestly seeking the way by night. During his free time, he would travel light, carrying supplies, trekking over mountains and rivers, enduring severe winters and scorching summers without a single day’s interruption” (Mutō 1911, p. 812).

In the collaborative process of reform, Nagaoka Monitor’s talents and character had a significant impact on Yokoi Shōnan, making him aware of the importance of talent selection. Against this backdrop, Yokoi Shōnan proposed three pertinent suggestions for the reform of the domain school, starting from the method of student selection: “Select domain samurai with ambition, virtue, and talent to become dormitory students; choose the offspring of the domain nobility who can endure hardship to eliminate the drawbacks of hereditary privilege and cultivate talents for national service; increase the number of students to twenty-five and enrich their provisions to facilitate their studies” (Motoda 1969, p. 20).

According to contemporary scholars, Yokoi Shōnan’s suggestions were adopted, and talent selection thus became an important aspect of the Jishūkan reform. After the reform began, the appearance of the students at the domain school changed significantly, as they vied to study hard and improve their knowledge (Tsutsumi 2011, p. 114). Moreover, in terms of content, Yokoi Shōnan placed great emphasis on knowledge directly related to national governance. He argued: “All studies should provide insight into the rise and fall of governance throughout history, contributing to one’s own wisdom and knowledge. One must extensively study the history of the Han and Wei dynasties and not limit oneself to recent trivialities. The Twenty-Two Histories should be read; otherwise, one will be insufficient for governance” (Motoda 1969, p. 21).

From this, we can see that during his tenure as Dormitory Chief, Yokoi Shōnan had already developed a practical orientation focused on national governance and put it into practice. The impetus for Yokoi Shōnan’s philosophy of practical studies during this period was not any existing doctrine but rather the necessity to address the real problems facing the Kumamoto Domain.

Although the reforms led by Nagaoka Monitor and Yokoi Shōnan achieved good results, they ultimately came to an end due to internal political struggles and personnel changes within the Kumamoto Domain. In February of the tenth year of the Tenpō era (1839), Shimotsu Kyūya, a supporter of the Jishūkan reforms, was dismissed from his position. In the same month, the Kumamoto Domain issued orders for Yokoi Shōnan to study in Edo, and the following month, Nagaoka Monitor resigned from his position as “Head of Martial and Literary Arts”. Consequently, the reforms were terminated. For the Kumamoto Domain, this signified a setback in administrative reform, but for Yokoi Shōnan, the journey to Edo provided an opportunity for a significant leap in his philosophy of practical studies (Yamasaki 2006, p. 36).

As mentioned earlier, during his time in Edo, Yokoi Shōnan encountered various scholars such as Fujita Tōko, Hayashi Shūzai, Satō Issai, and Matsuzaki Kōdō, exposing him to a range of ideas. More importantly, during this journey, he read On National Isolation by the German physician Engelbert Kämpfer, associated with the Dutch East India Company, which shifted his focus toward a broader world beyond Japan. On National Isolation is a section of Kämpfer’s History of Japan, which was translated into Japanese by the Dutch scholar Shizuki Tadao in 1801. Through this book, Yokoi Shōnan developed two perspectives on the external world: First, that the common Japanese perception of Edo as the largest city in the world was mistaken; although major European cities like Rome, Paris, and London were smaller than Edo, there were larger cities such as Cairo, Mexico City, and Moscow beyond the centers of Western Europe. Second, he learned that the Portuguese spread Catholicism to create confusion among the populace, causing Japan’s wealth to flow abroad and ultimately aiming to conquer Japan (Yokoi 1938g, pp. 809–12).

Additionally, the book made Yokoi Shōnan realize that the Western world had already begun to investigate Japan: “The state of the world can be known not just by those with eyes among us; the Westerners have already understood it. As stated by Kämpfer in On National Isolation, they see the formidable mountains and seas that separate us, recognize our strong spirit, and know that our land is self-sufficient in many resources” (Yokoi 1938a, p. 692). Although Yokoi Shōnan had not yet formed his later ideas on “opening the country”, On National Isolation had already made him aware of the importance of understanding the external world, laying the groundwork for his later development of international awareness.

Subsequently, in the second year of the Ansei era (1855), Yokoi Shōnan read the Illustrated Account of Maritime Nations by Wei Yuan, marking a formal shift in his stance toward advocating for the opening of Japan. According to his disciple Naitō Taikichi, after reading the Illustrated Account of Maritime Nations, “he increasingly advocated for the opening of the country, engaging in discussions with me daily, neglecting sleep and food for several hundred days. The teacher spoke of military strategy, and I responded with medical knowledge, which proved to be quite enlightening” (Naitō 1827, p. 7).

From Yokoi Shōnan’s writings, it is evident that his views on foreign relations underwent significant changes before and after reading the Illustrated Account of Maritime Nations. Prior to reading this book, Yokoi Shōnan was a staunch proponent of expelling foreigners. In a letter written in the third year of the Kaei era (1850) to Fukui Domain samurai Santera Sansaku, he stated, “For our sacred land, which has stood independently between heaven and earth for three thousand years, no country in the world can compare. Even if all the people were to die and the land were to be exhausted, there would be no reason to discuss peace with the barbarian thieves” (Yokoi 1938f, pp. 135–36). At that time, Yokoi Shōnan still referred to Western countries as “barbarian thieves”. However, after reading the Illustrated Account of Maritime Nations, he began to advocate for trade with Western countries and viewed foreign nations as upholding the “public good”. In his work Three Essays on National Affairs, written in the first year of the Man’en era (1860), he remarked, “Various countries open the key to Japan through the public good, yet Japan still clings to the old view of national isolation, pursuing private interests in governance without understanding the principles of trade. How foolish this is” (Yokoi 1938e, p. 40).

Chronologically, Yokoi Shōnan’s shift in thought indeed occurred around the time he read the Illustrated Account of Maritime Nations, and his descriptions of Western countries clearly reflect insights gained from this work. For instance, Wei Yuan characterizes the United States in the Illustrated Account of Maritime Nations as a civilized nation that is both militarily capable and intellectually advanced, both public-minded and considerate, as well as both wealthy and amicable, focusing on aspects such as politics, economics, and foreign policy (Wei 2004, p. 1585). Similarly, in Three Essays on National Affairs, Yokoi Shōnan offers high praise for the United States: “Since Washington, the United States has established three great principles. First, there is no greater evil in the world than killing; therefore, it complies with heavenly will by striving to end wars across the globe. Second, it seeks knowledge from all nations of the world to enhance governance and education. Third, the power of the national chief is entrusted to the virtuous rather than passed down to one’s children, abolishing the concept of lords and subjects, focusing on public peace. As for political strategies and various skills and tools, they take all that is good and beautiful from around the Earth as their own, promoting the benevolent spirit of nurturing life” (Yokoi 1938e, pp. 39–40).

In the passage above, Yokoi Shōnan’s perspective on the United States aligns almost exactly with that found in the Illustrated Account of Maritime Nations, and his praise for the U.S. echoes Wei Yuan’s sentiments. Contemporary scholars have noted that Yokoi Shōnan’s later work, Discussion on Overseas Situations and National Defense, written after the second year of the Ansei era, also inherits Wei Yuan’s viewpoints. (Gen 2013, p. 131) Importantly, aside from the worldly knowledge found in educational contexts, Yokoi Shōnan’s practical learning orientation mainly manifests in his theories on political “public governance”, economic “wealth of the nation”, and foreign relations’ “opening the country”. These ideas emerged primarily after the second year of the Ansei era, indicating that his understanding of the external world, particularly his acceptance of the Illustrated Account of Maritime Nations, served as another catalyst for the formation of Yokoi Shōnan’s practical learning philosophy.

It is important to emphasize that, although the concept of “practical learning” in the history of ideas originally comes from Cheng Yi’s statement that “governing through the classics is practical learning” (Cheng and Cheng 2004, p. 2), the “practical learning” advocated by Takase Takejirō, who claims that Yokoi Shōnan “derived his practical learning from Wang’s school”, has clearly diverged from its original meaning and reflects a modern perspective. Scholars have pointed out that “practical learning is a multi-dimensional category. From a cosmological perspective, it combines philosophy and natural science; from a value perspective, it encompasses various disciplines that trigger and sustain the development of social functions; from a knowledge perspective, ‘practical learning’ refers to practical knowledge” (Li 1995, p. 42).

By this standard, Yokoi Shōnan’s educational reform ideas and his arguments for opening the country align with the developmental direction of late Edo society and exhibit strong practicality. Takase Takejirō likely referred to Yokoi Shōnan’s scholarship as practical learning in this sense. Therefore, exploring the sources of Yokoi Shōnan’s practical learning philosophy should be conducted with a comprehensive analysis of his academic trajectory and practical experiences. Neither Yangming philosophy nor any other single school of thought can independently constitute the background of Yokoi Shōnan’s practical learning philosophy.

5. Conclusions

From the analysis above, it is clear that the claim in modern Japanese academic circles that Yokoi Shōnan “derived his practical learning from Wang’s school” is unfounded. Not only did Yokoi Shōnan not draw on Yangming philosophy as the source of his practical learning thought, but he also held a critical stance towards it. In fact, the formation of Yokoi Shōnan’s practical learning philosophy underwent a lengthy process. His experiences in the reform of the domain school, exchanges with thinkers from various Japanese schools during his study abroad, understanding of the Western world, and discussions in the Practical Learning Reading Society all played significant roles in the emergence of his practical learning philosophy. It is difficult to simply attribute his practical orientation to the influence of a particular ideology.

Crucially, in modern Japan, aside from Yokoi Shōnan, many other leaders of the late Edo period reform movement were also regarded as proponents of Yangming philosophy. Takase Takejirō noted in Yangming Philosophy in Japan: “The heroes and luminaries who rose during the final years of the shogunate, such as Sakuma Shōzan, Koizumi Kanso, Yoshida Shōin, Takasugi Shinsaku, Unno Ryuū, and Yokoi Shōnan, all practiced Yangming philosophy to cultivate their minds and character, embedding loyalty and righteousness in their bones, discussing life and death with ease, and achieving great undertakings that shook the heavens and earth”. (Takase 1898, p. 32) However, from the perspective of scholarly lineage and academic thought, these late Edo period reformists cannot actually be classified as part of the Yangming school. Japanese scholars like Takase Takejirō erroneously categorized these political activists as members of the Yangming school, which can be partly attributed to the needs of political movements (Huang 2020). This suggests that there is a discrepancy between the genealogical framework of Japanese Yangming philosophy constructed by modern scholars and the actual dissemination of Yangming thought in early modern Japan. Consequently, there inevitably exists a skewed understanding of the pragmatic nature of Japanese Yangming philosophy and its relationship with the Meiji Restoration. For this reason, contemporary scholars should exclude extra-academic factors from the study of the history of ideas, return to the historical context of Yangming philosophy during the late Edo period, and redefine its position in modern Japanese history.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data are available from the author.

Conflicts of Interest

The author declares no conflicts of interest.

Footnotes

Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

References

Cheng, Hao 程颢 Cheng, Yi 程颐. Er Cheng Ji 二程集 [The Collected Works of the Two Chengs]; Zhonghua Shuju: Beijing, 2004.

Gen, Ryōen 源了圓. Yokoi Shōnan Kenkyū 横井小楠研究 [Yokoi Shōnan Studies]; Fujiwara Shoten: Tokyo, 2013.

Hiraishi, Naoaki 平石直昭. Ōtsuka Taiono Gakuha no Zhuxixue Shisō 大塚退野学派の朱子学思想 [The Confucian Thought of the Ōtsuka Taien School]. Yokoi Shōnan 1809–1869: “Kōkyō” no Senkusha 横井小楠1809–1869——”公共”の先駆者 [Yokoi Shōnan 1809–1869——Pioneer of the “Public”]; Ryōen, Gen 源了圓. Fujiwara Shoten: Tokyo, 2009; pp. 41-59.

Huang, Ying 黄滢. Lun “Riben Jinshi Yangmingxue Xipu” de Jindai Shengcheng 论”日本近世阳明学系谱”的近代生成 [On the Modern Formation of the “Japanese Early Modern Yangming School Genealogy”]. Waiguo Wenti Yanjiu 外国问题研究 [Foreign History Studies]; 2020; 235, pp. 109-16.

Imanaka, Kanji 今中寛司. Shōnan-gaku no Jukyō-teki shisō keitai ni tsuite 小楠学の儒教的思想形態について [On the Confucian Thought Form of Shōnanism]. Shirin; 1969; 52, pp. 33-64.

Inoue, Tetsujiro 井上哲次郎. Nihon Yōmeigaku-ha no tetsugaku 日本陽明学派之哲学 [The Philosophy of the Japanese Yangming School]; Fuzanbo: Tokyo, 1900.

Karashima, Ranken 辛島蘭軒. Shioi Karashima Sensei Bozimei 塩井辛島先生墓誌銘 [Epitaph for Mr. Shioi Karashima]. Higo Sentetsu Iseki 肥後先哲偉蹟 [The Great Achievements of the Philosophers of Higo]; Itsuo, Mutō 武藤厳男. Ryūbunkan: Tokyo, 1911.

Kumamoto-ken Kyōikukai 熊本県教育会 [Kumamoto Prefecture Educational Association]. Kumamoto-ken Kyōiku-shi 熊本県教育史 [The History of Education in Kumamoto Prefecture]; Kumamoto-ken Kyōikukai: Kumamoto, 1931; 1.

Li, Suping 李甦平. Zhongguo·Riben·Chaoxian Shixue Bijiao 中国·日本·朝鲜实学比较 [Comparative Studies of Practical Learning in China, Japan, and Korea]; Anhui Renmin Chubanshe: Hefei, 1995.

Lu, Jiuyuan 陆九渊. Lu Jiuyuan Ji 陆九渊集 [The Collected Works of Lu Jiuyuan]; Zhonghua Shuju: Beijing, 1980.

Matsuura, Rei 松浦鈴. Yokoi Shōnan: Jugaku-teki Seigi to wa Nanika 横井小楠：儒学的正義とは何か [Yokoi Shōnan: What is Confucian Justice?]; Asahi Shinbunsha: Tokyo, 2000.

Motoda, Eifu 元田永孚. Kanreki no ki 還暦之記 [Record of the Sixtieth Year]. Motoda Eifu bunsho 元田永孚文書 [The Documents of Motoda Eifu]; Takehiko, Motoda 元田竹彦 Muneomi, Kaigo 海後宗臣. Motoda bunsho kenkyūkai 元田文書研究会 [The Motoda Document Research Association]: Tokyo, 1969; 1.

Mutō, Itsuo 武藤厳男. Higo Sentetsu Iseki 肥後先哲偉蹟 [The Great Achievements of the Philosophers of Higo]; Ryūbunkan 隆文館: Tokyo, 1911.

Naitō, Taikichi 内藤泰吉. Hokusō Kanwa 北窓閑話 [The Northern Window Chats]; Minyūsha: Tokyo, 1827.

Takase, Takejirō 高瀬武次郎. Nihon no Yōmeigaku 日本之陽明学 [Japanese Yangming School]; Tekka Shoin: Tokyo, 1898.

Tsutsumi, Katsuhiko 堤克彦. Yokoi Shōnan no Jitsugaku Shisō 横井小楠の実学思想 [Yokoi Shōnan’s Practical Learning Thought]; Perikan-sha: Tokyo, 2011.

Wang, Shouren 王守仁. Da Luo Zheng’an Shaozai Shu 答罗整庵少宰书 [Letter to Luo Zheng’an, Junior Official]. Wang Wencheng Gong Quanshu 王文成公全书 [The Complete Works of Wang Wencheng]; Xiaoxin, Wang 王晓昕 Pinglue, Zhao 赵平略. Zhonghua Shuju: Beijing, 2015a; 1, pp. 93-94.

Wang, Shouren. Da Gu Dongqiao Shu 答顾东桥书 [Letter to Gu Dongqiao]. Wang Wencheng Gong Quanshu; Wang, Xiaoxin; Zhao, Pinglue. Zhonghua Shuju: Beijing, 2015b; 1, pp. 55-56.

Wei, Yuan 魏源. Haiguo Tu Zhi 海国图志 [The Illustrated Treatise on the Maritime Nations]. Wei Yuan Quanji 魏源全集 [The Complete Works of Wei Yuan]; Yuelu Shushe: Changsha 长沙, 2004.

Wen, Qiaohui 温巧慧. Yokoi Shōnan Yanjiu Zongshu 横井小楠研究综述 [A Review of Yokoi Shōnan Studies]. Xibu Xuekan 西部学刊 [Westward Journal of Studies]; 2023; 184, pp. 125-31.

Yamasaki, Masatake 山崎正董. Yokoi Shōnan: Denkihen 横井小楠·伝記篇 [Yokoi Shōnan: Biographical Volume]; Meiji Shoin: Tokyo, 1938.

Yamasaki, Masatake. Yokoi Shōnan den 横井小楠伝 [The Biography of Yokoi Shōnan]; Matsuno Shoten: Shūnan, 2006.

Yokoi, Shōnan 横井小楠. Doku Sakokuron 讀鎖国論 [On the Theory of National Isolation]. Yokoi Shōnan: Ikōhen 横井小楠·遺稿篇 [Yokoi Shōnan: Posthumous Works Volume]; Masatake, Yamasaki. Meiji Shoin: Tokyo, 1938a; pp. 692-93.

Yokoi, Shōnan. Gakuji no shō kōgi 学而之章講義 [Lectures on the Book of Learning]. Yokoi Shōnan: Ikōhen; Masatake, Yamasaki. Meiji Shoin: Tokyo, 1938b; pp. 931-33.

Yokoi, Shōnan. Honjō Ichirō e 本庄一郎へ [To Ichirō Honjō]. Yokoi Shōnan: Ikōhen; Masatake, Yamasaki. Meiji Shoin: Tokyo, 1938c; pp. 126-33.

Yokoi, Shōnan. Kankai Jisshu 感怀十首 [Ten Poems of Sentiment]. Yokoi Shōnan: Ikōhen; Masatake, Yamasaki. Meiji Shoin: Tokyo, 1938d; pp. 876-77.

Yokoi, Shōnan. Kokushi Sanron 国是三論 [Three Theories on the National Question]. Yokoi Shōnan: Ikōhen; Masatake, Yamasaki. Meiji Shoin: Tokyo, 1938e; pp. 29-56.

Yokoi, Shōnan. Mitsudera Mitsusaku e 三寺三作へ [To Mitsudera Mitsusaku]. Yokoi Shōnan: Ikōhen; Masatake, Yamasaki. Meiji Shoin: Tokyo, 1938f; pp. 134-38.

Yokoi, Shōnan. Yūgaku zasshi 遊学雜誌 [Study Abroad Journal]. Yokoi Shōnan: Ikōhen; Masatake, Yamasaki. Meiji Shoin: Tokyo, 1938g; pp. 798-822.

Zhu, Xi 朱熹. Dushu Fa Xia 读书法下 [On the Method of Reading]. Zhuzi Yulei 朱子语类 [Zhu Xi’s Collected Sayings]; Zhonghua Shuju: Beijing, 1986; 11, pp. 176-98.

Zhu, Xi. Mengzi Jizhu 孟子集注 [The Collected Annotations on Mencius]. Sishu Zhangju Jizhu 四书章句集注 [The Collected Annotations on the Four Books]; Zhonghua Shuju: Beijing, 2012a; vol. 13, pp. 338-48.

Zhu, Xi. Zhongyong Zhangju Xu 中庸章句序 [The Preface to the Chapter on the Doctrine of the Mean]. Sishu Zhangju Jizhu; Zhonghua Shuju: Beijing, 2012b; pp. 14-16.