Heresy and Liminality in Shingon Buddhism: Deciphering a 15th Century Treatise on Right and Wrong

: Traditional historiography of Japanese Buddhism presents the Muromachi period as an era of triumph for Zen, and of decline for the previous near-hegemony of Esoteric Buddhism. However, for the Shingon school, the period from the late Middle Ages to early Edo period was rather a phase of expansion, especially in the more remote locales of Eastern Japan. Focusing on a text authored during the ﬁfteenth century, this article will analyze how this idea of the outskirts or periphery was integrated with the process of creation of orthodoxy in local Shingon temples. In doing so, it will shed new light not only on the evolution, but also on the epistemological role of discourse relating to heresy, and on their role in the legitimation of monastic lineages.


Introduction
In one of his many seminal studies, Carlo Ginzburg analyzed what he called the mental world of a sixteenth century miller from North-Eastern Italy, known as Menocchio. An avid reader, Menocchio had come to hold very peculiar philosophical and religious views that led him to create a whole cosmogony centered around "the cheese, the milk, the worm-angels, God, the angel created out of chaos". This portrait provided a vivid and living viewpoint into the little-studied culture of the subordinate class of society. In doing so, Ginzburg described how Menocchio developed an extremely original and composite worldview, which saw him condemned by the Church and burned at the stake in 1599 (Ginzburg 1982).
Due to a lack of comprehensive sources comparable to the records of the inquisition, it would be difficult to apply Ginzburg's work to a Japanese context. This study will rather draw inspiration from it, and also from previous work by Bernard Faure on the medieval Zen monk Keizan Jōkin 瑩山紹瑾 (1268-1325) (Faure 2011), and attempt to decipher the mental world of a Japanese monk called Shunkai 俊海 (before 1389-after 1454). Shunkai was no Menocchio-far from it. He did not leave complete records of his thoughts and readings. He was also never accused of heresy, nor was he put on trial. In Japan, actual trials for heresy or erroneous beliefs were unknown before the arrival of Christianity. 1 In fact, this monk fought for orthodoxy, as he wrote a text condemning heretical practices in the Shingon school and in his temple during this time.
However, Shunkai's viewpoint in this text is provoking for several reasons. First of all, it is one of the few texts related to heresy dating from this period. Recent studies have shed new light on the origins of the discourses of heretical practices within the Shingon school through the thorough analysis of the alleged Tachikawa lineage and its evolution. However, because of the sources available, such studies focus on the early medieval period, with the Juhōyōjinshū 受法用心集 by Shinjō 心定 (ca. , and in the fourteenth century, with the Kōyasan monk Yūkai 宥快 (1345-1416). 2 There were also subsequent developments, up to at least the early Edo period (Rappo 2018. Shunkai's Shingishō 真偽抄, which will be the main subject of this study, is a fascinating source that showcases the main preoccupations of its author. Shunkai was concerned primarily with the fact that he was spreading the Shingon teachings throughout the countryside (inaka 田舎), far from the religious center of the capital, and from Daigoji 醍醐寺, the leading temple of his lineage. This discourse on periphery is a constant theme in Shingon texts discussing heretical lineages or practices. Positioning farther from the center tends to engender unorthodox practices. This was in fact one of the main circumstances-according to Shinjō and Yūkai-that led to the emergence of the Tachikawa lineage, which was allegedly a local blend of Shingon esotericism with Onmyōdō 陰陽道 and other practices, made in the remote (at the time) Musashi Province (Iyanaga 2004, pp. 24-25). This discourse of the periphery must be understood within a particular historical context, however. The late medieval period, which can be seen as a triumph of Zen, was also a phase of expansion and diffusion of the Shingon school, especially in eastern Japan. As demonstrated by a previous study by Watanabe (2010), Shunkai was one of the major figures in this movement.

Author and Context
Shunkai came from the Shimotsuke Province in northeastern Japan. As a child, he traveled to the capital and studied at Daigoji, one of the major centers of the Shingon school in Kyoto. He is known to have resided in the Jōrin'in 乗琳院 of the Kami-daigo. During his time at Daigoji, he was initiated into multiple lineages, including Jizō'in 地蔵院流 and especially Matsuhashi 松橋流. 3 At some point around 1409, Shunkai returned to his home province. As Masahito Sakamoto has shown, he followed a pattern that can be observed in the lives of several other Shingon monks from the late Muromachi to the early Edo period: monks who have inherited the status of true heir to a major lineage (shōchaku 正嫡) at important temples in the capital (e.g., Tōji, Daigoji, etc.) also actively worked to spread such knowledge to remote places, in the countryside of northeastern Japan (Sakamoto 2004, p. 295).
In 1431, Shunkai composed the Shingishō in a temple called Tahara Mikkōji 田原密興寺 in Shimotsuke Province. According to the colophon, it was based on oral teaching tracing back to Ikkai一海 (1116Ikkai一海 ( -1179, the founder of the Matsuhashi lineage (Matsuhashi-ryū 松橋流). 4 As a whole, sources regarding Shunkai's life are relatively scarce. However, he is mentioned in later monastic genealogies, such as the Misshū kechimyaku-shō 密宗血脈鈔. As Watanabe has shown, there is even a variant of this text containing additional details on him, a fact that proves his influence in the lineage transmission process (Watanabe 2010).

The Matsuhashi Lineage
Founded by Ikkai, the Matsuhashi lineage traces back to Daigoji, and it is the result of a schism that occurred within the Sanbō'in 三宝院 lineage branch during the middle of the eleventh century. Due to an inheritance dispute between him and Jichiun 実運 (1105-1160), a monk who was to become one of the most important patriarchs of Daigo, Ikkai had established a new lineage, that of Matsuhashi, named after the locality where a temple had been established by his predecessor Genkai 元海 (1093-1156) (Shibata 2010, pp. 139, 192-95, 314-16). The genealogy of the lineage, dated to 1635, which can be found in the Sanjūrokuryū daiji 三十六流大事, shows that this lineage continued after Ikkai, with the monk Gakai 雅海, then Zenken 全賢, Jōshin 浄真, and after a few generations, all the way to Shunkai via his master Shunjō 俊盛 (Zokushingonshū zensho kankōkai 続真言宗全書刊 行会 1985, p. 390).
The list of members of one of these lineages is called "genealogy by blood" (kechimyaku 血脈). The temples thus form true "Dharma lineages" (hōryū 法流), or monastic lineages (monryū 門流), which emphasize the possession and transmission of knowledge perceived as secret and exclusive. These genealogies are presented as a direct and continuous transmission, from the mythical origins of the Shingon school to the founder of the lineage in question and his disciples. The term kechimyaku, which evokes blood ties, can sometimes be taken literally; the son of a monk succeeding his father (Nishiguchi Junko 西口順子 1987, p. 186 et seq.). However, these are spiritual lineages, and the term genealogy, or bloodline, should be understood primarily in its figurative sense of doctrinal and ritual filiation.
Interestingly, the famous Saidaiji monk Eison (or Eizon 叡尊 1201-1290) is also known as a prominent member of the lineage. In fact, Eison was a member of a different branch, which stemmed from a split after Ikkai. The Saigyokushō 西玉抄, a text written in 1314 by the monk Monkan contains a genealogy of Eison's lineage. Monkan-who signs as Ju'on 殊音, his name as a Saidaiji monk-presents himself as the disciple of Shinkū 信空, one of Eison's five disciples initiated into Esoteric Buddhism. Monkan also mentions the alternative lineage, which would in fact become the main one, started with Gakai, and his list is mostly identical to what appears the Sanjūrokuryū daiji until a monk named Shun'yo 春誉, who is listed four generations before Shunkai. Since the Saigyokushō was written during the fourteenth century, Shunkai would obviously be absent (Rappo 2017a, pp. 179-83).
Such schisms were common in esoteric lineages, but they should not be seen as anecdotic. Establishing correct genealogies of the proper transmissions of doctrine was one of the major goals of all the monks who expounded on the idea of heresy in Shingon Buddhism. One of the most important figures in this context is Kyōi 恭畏 (1564-1630), a Shingon monk known for his treatises on heresy as well as his famous compendium on all the Esoteric lineages of his times (Misshū kechimyaku-shō 密宗血脈抄). Yūkai, the main driving force behind such discourses-especially concerning the Tachikawa lineage-was also extremely concerned with the transmission of correct Shingon lineage and doctrine .

The Manuscript and Its Contents
The only known copy of the Shingishō is a manuscript preserved at the Chishaku'in temple, in Kyoto. The extant edition, last copied in 1778, is combined with a glossary of key terms in Shingon. The title of the text was popularized in academic circles through the work of Itō Satoshi (Itō 2003, pp. 199-200) who mentions it within the context of a discussion on the history of apocrypha inside the Sanbō'in lineage of the Shingon school. The next few pages will discuss the structure and the contents of the manuscript, focusing on a few specific issues. Being a booklet format, the manuscript has page numbers in its microfilm version. They will be used as references in this article.
The Shingishō begins on page 460 of the microfilm, with a discussion of the basic rules of Shingon doctrine, and especially of its transmission: kegyō 加行 and kanjō 灌頂. Kegyō is a well-known basic initiation process still practiced in Shingon today. It was systematized in Japan during the late Heian period, and it concretely consists of four steps (shido 四度), the jūhachidō 十八道, the two mandalas, and the homa fire ritual, during which the candidate learns all the basic knowledge needed to perform rituals under the guidance of a master (Rappo 2008).
Kegyō usually ends with a consecration ritual (kanjō 灌頂, Skt. abhis . eka). In China, the initiation of a ritualist already tended to become a standardized process, culminating in the anointing of transmission of the Law (denbō-kanjō 伝法灌頂). In Japan, it formed the cornerstone of the system of "transmission from master to pupil" used in the Shingon school. 5 Shunkai's insistence on this fundamental aspect of the Shingon teachings is logical, as texts related to kegyō are very common in the libraries of Shingon temples. However, the combination of this focus on the basics with a discussion on heresy later in the text is a very interesting characteristic of this text. Because the structure of the text begins with the most basic rules and moves on to dubious teaching and texts, one can clearly determine that Shunkai's view on heresy likely emerged from very concrete concerns relating to what he was experiencing in his daily duties. As Watanabe (2010) has shown, Shunkai was a very active monk at several temples in Shimotsuke Province. The Mikkōji of Tahara was thus one of the many places he frequented, and he conscientiously built an extensive network of temples and religious sites in the region.

Countryside and Outskirts
Judging from the vocabulary that Shunkai uses in the first part of the Shingishō, his concerns with the most important rules and practices of Shingon were also a consequence of how he saw his position as the superior of a temple located in northern Kantō, a place which at the time was seen as extremely remote and far away from the religious and power centers.
In fact, the term "countryside" (inaka 田舎) appears several times within the text. While it does not necessarily have a negative meaning per se, Shunkai uses it in opposition to the center, which is, for him, the Daigoji temple in Kyoto. Moreover, several mentions of the countryside are found in the text, such as the expression "rules of the countryside" (inaka no hōsoku 田舎ノ法則). While this can be a humble way for Shunkai to describe his own temple, the fact is that he points out the existence of different, and always looser, rules in the countryside compared to the religious centers. This not only shows that Shingon disciplinary rules could be modified according to specific circumstances, 6 but it also suggests a certain idea of the countryside as a liminal space, where monastic discipline-and probably public morals as a whole-are not taken as strictly as in more "civilized" places.
For example, Shunkai says, in his description of the last part of the Shido kegyō process, the homa ritual, that in the "countryside, the number of days is one third of that of the main temple, and thus the homa ritual (is transmitted) in thirty-seven days". 7 He also adds that in the countryside, the period dedicated the whole homa ritual is, in the case of beginners, reduced to seventy-five days compared to the one-hundred days of the main temple. 8 Variations in the length of the kegyō process are not necessarily exceptional by themselves, but the multiple references to local accommodations reveal a larger pattern. Shunkai makes no mention of changing the way things are done in the countryside, and seems content with describing them and their relationship to the rules at Daigoji.
Similar adjustments are seen with specific rituals, such as the Rishu zanmai 理趣三昧: "On the Rishu zanmai. In the countryside, there are no processions chanting sutras (gyōdō 行道). However, in the Rishu zanmai ritual conducted each morning in the Seiryō shrines both on the top and below the mountain, when the rite is performed by three people, one leads the offerings (kuyō 供養) while the two others do the processions (gyōdō)". 9 While the term inaka may not have that much pejorative connotation in the text, another part, concerning the recitations of the Rishukyō, uses the much more telling word of hendo 辺土 (ms. 471). In medieval Japan, this term is often used in the expression remote islands "scattered in the ocean like millet grain" zokusan hendo 粟散辺土, which describes Japan's place as an isolated land in the Buddhist world (Itō 2018, p. 132). However, the term has a broader sense of outskirts, or borderlands, with an insistence on being on the margins, either in a spatial or social sense.

Liminality and Heresy
The Shingishō thus contains multiple references to a certain idea of liminality and marginality encompassed in the notion of countryside. Previous studies have amply shown how all the major texts on heresy before the Shingishō dwell on the very same imagery to discredit certain monks or lineages. This is, of course, the case with the Tachikawa lineage.
As Iyanaga Nobumi has shown, a similar rhetoric can be found both in Yūkai's Hōkyōshō 宝鏡鈔 (1375), and even before, in Shinjō's Jūhō yōjinshū 受法用心集. Speaking on the religious group which spread the teaching of the alleged skull ritual, Shinjō insists on the fact that "nine out of ten Shingon masters in the countryside believe this is the essence of Esoteric Buddhism". 10 While this is probably an exaggeration, the idea that strange teachings are diffused more easily in the countryside than in a major temple is a mainstay in such discourses. Another part from the same text that describes the dissemination of the skull ritual to ignorant and commoners from the remote countryside (inaka hendo 田舎辺土). 11 As we will see, this notion does not necessarily reflect historical reality (although it may do so partially), but should rather be seen as a part of the worldview of a certain religious elite. This is especially the case with Yūkai, who insists on this argument in his account on Monkan and the Tachikawa lineage (Iyanaga 2011, pp. 808-9). Yūkai's rhetoric was followed by almost all the subsequent texts dealing with the matter of the Tachikawa lineage . However, this does not mean that this view accurately describes the actual transmission process of such teachings during his times. In fact, his attacks also target the local esoteric lineage of the Miwa, in the Yamato Province, where, as Anna Andreeva nicely puts it, his "opprobrium was directed mostly toward various "country bumpkins," Buddhist practitioners and holy men residing in the countryside". However, he fails to mention that such teachings were also transmitted in the very centers of Shingon, such as Kōyasan and Daigoji, and sometimes by high-ranking monks (Andreeva 2017, pp. 134-35). As is often the case with heresy, such discourses actually reveal more details on the thought process of their authors than they do about the real beliefs of the people they are accusing.

Lineage and Proper Transmission
While Shunkai does not necessarily look down upon the countryside, he clearly sees the remote location of northern Kantō temples as a reason to be extremely careful in the transmission of proper esoteric knowledge. This is even more apparent in a later section of the text, where Shunkai meticulously describes his education not only as a Shingon monk, but also his education in Buddhism in general.
The part called "studying the other schools" (ms. 473) thus tells his own experience in the learning centers of western Japan. This section was most certainly the basis for the details on this subject given by his biography in the Misshū kechimyakushō. 12 As a whole, his idea of education, which is consistent with his times (Rappo 2021), was being accepted by a master and then gaining access to the transmission of texts and doctrines (kyōsō 教相) or rituals (jisō 事相). His prose thus consists of an enumeration of names of temples, masters, and texts.
He starts by explaining his academic background in the other schools besides Shingon. In medieval Japan, it was common to be educated in the traditional schools-especially the Nara ones-a pattern common to both Shingon and Tendai monks (on Tendai, see Watanabe 2014). The first school mentioned is the Hossō 法相 school, which Shunkai likely learned at Kōfukuji. He then learned Sanron 三論 at Tōdaiji and Kegon 華厳 at the Kaidan'in 戒壇院 of the same temple. Regarding the Kusha 倶舎 school, Shunkai explains that since it is a large and complex matter, he studied it under the patronage of several masters. First at the Negoro Shōhenchi'in 根来正遍知院. Before being destroyed during the sixteenth century, Negoroji, the center of what would eventually become the Shingi 新 義 branch of Shingon, was a major place of learning in Japanese Buddhism, counted as a university by Francis Xavier in his letters (Rappo 2021).
Shunkai then describes how he studied Tendai, and not only on the surface. He actually learned with masters of the two major lineages of the school at the time, the Eshinryū 恵真流 and Danna-ryū 旦那流 (ms. 474; on these lineages, see Stone 1999, pp. 34-35). 13 He, however, describes Tendai as being an exoteric (kenkyō 顕教) teaching, and he mentions the old Jōjitsu 成実 school after it. On this school, Shunkai adds that since it is extinct in Japan, there is no need to learn about it.
The next section details his education to Shingon Esotericism. He divides it into two parts, which are consistent with the usual process: doctrine and ritual. For the doctrine part, Shunkai studied extensively at Kōyasan, mostly under the guidance of Chōgaku 長覚法印 at the Kōyasan Nanshōin 高野山南照院, for six years. Originally from the Dewa Province, Chōgaku completed his Shingon training in the Tōzen'in 東禅院 on Mount Kōya beginning in 1362, before traveling the country and learning about various religious traditions, including Zen and Shintō. Upon his return in 1403, he moved to the Muryōju'in 無量寿院 of Mount Kōya, and became an influential figure in the doctrinal studies of the complex founded by Kūkai (Rappo 2017a, pp. 87-88).
Interestingly, Shunkai also studied with Yūkai. We do not have details of what he learned from this major figure of the history of heresiology in Japanese Buddhism, but it shows that a direct connection existed between them. 14 This, of course, explains Shunkai's reliance on Yūkai's work for his own classification of heretical texts. The fact that Shunkai was able to study with Chōgaku and Yūkai is also interesting due to the reputed rivalry between them (Rappo 2017a, p. 88). The complex web of relationships described by Shunkai tends to nuance the impact of such views, as it demonstrates the ability for rival lineages to coexist without necessarily leading to major friction.
In this section, Shunkai also mentions how he gained access to other Shingon lineages, such as those of the Sai'in 西院 and Kajūji 勧修寺. More specifically, Shunkai tells us that he became a disciple of the Kōmyōshin'in hō'in 光明心院法印 (ms. 474). This figure can be identified as Kōban 弘鑁 (1362-1426), a member of the Jizō'in 地蔵院 lineage of Daigoji (Watanabe 2010, pp. 480, 488). This Kōban has to be distinguished from the monk of the same name, who lived in the Kamakura period, and is known to have worked with the monk Hōkyō 宝筐, or Rendōbō 蓮道房, a figure associated with the Kongōō'in 金剛王院 lineage, one of the many branches that would become assimilated to the Tachikawa heresy (see (Takahashi 2016) and especially (Andreeva 2015)). As a whole, this section shows a clear pattern of him trying to study with masters from all the different spheres composing Shingon Buddhism in the late fourteenth to early fifteenth century.
After having presented his pedigree as a monk educated in the centers of Shingon and the other major schools of Japanese Buddhism, Shunkai closes this chapter by explaining the practices of lineage transmission at his temple, where he explicitly mentions that disciples were educated in several lineages: Jizō'in,Hōon'in 報恩院,and Matsuhashi (ms. 475). This confirms the observation by Watanabe (2010) that Shunkai was a major actor in the diffusion of not only the Matsuhashi lineage, but also the other lineages related to the Sanbō'in, such as the Hōon'in and Jizō'in.
While this section can be seen as a long enumeration of tedious details, there is a clear pattern in Shunkai's writing. By providing extensive credentials, and by showing that he studied all the main lineages of Shingon and had deep knowledge in Buddhism as a whole, he gives further credit to the next part of his text, where he deals directly with falsehoods and heresy.

The Fake Texts
As we have seen, the first part of the Shingishō does not directly mention the notion of heresy. However, Shunkai's insistence on getting the basics right and giving proper rules for initiation and transmission, as well as his detailed presentation of his credentials can also be seen as going hand in hand with his investigations into dubious texts and lineages.
The section on the fake and misleading works occupies the last few pages of the manuscript. Its contents are almost entirely consistent with later lists of heretical texts, and the very names of the works he mentions are mostly taken from Yūkai's own catalog . The first part is titled "On forged sealed certificates and oral transmissions and other things" (gisaku injin kuketsu-kyō tō no koto 偽作印信口決経等事). Shunkai's rhetoric bears a striking resemblance to later work, especially by Kenshō of Ninnaji, in that he tries to give concrete evidence proving why a text is fake . For example, the famous Tenchō injin 天長印信 (Sealed Certificates of the Tenchō Era, see Rappo 2018, p. 146 note 31), an alleged teaching given by Kūkai to his disciple Shinga 真雅 (801-879) of Jōganji 貞観寺 (in the colophon) is deemed a forgery due to the fact that Jōganji temple did not exist at the time of the transmission (ms. 475). Such arguments, while not necessarily completely convincing, clearly show an evolution in Shingon heresiology, focused on details of the transmission process and contradictions inside the texts, that would lead to the catalogs of heretical texts appearing during the late Muromachi and Edo period.
A whole section of this chapter also deals with one of the major characters of Yūkai's Hōkyōshō, Monkan. In fact, Shunkai's tries to explain how Monkan's main ritual, the Joint Ritual of the Three Deities (Sanzon gōgyōhō 三尊合行法), 15 is wrong from a doctrinal point of view. He interprets Monkan's reliance on the Yugikyō 瑜祇経, a canonical text, to create a consecration ritual as a "heresy (of the kind) almost unheard of," and he adds that in the "correct lineage" (shōryū 正流) of his school, such biased readings of this sutra are almost nowhere to be found. 16 In the next sentence, he goes even further by linking certain interpretations-probably including Monkan's views-of another canonical text, the Bodaishinron 菩提心論, to the sometimes criticized concept of five stages of gestation within the human body (tainai go'i 胎内五位), adding that such theories fabricated mantras and mudras (inmyō 印明) not present at all in the original text. 17 Here, we can see the evolution of Yūkai's rhetoric, which dealt more with Monkan's origins and a complex constellation of disparate elements to portray him as a heretic, than with textual matters. In this sense, Shunkai's is more convincing than his predecessor, as Monkan does, indeed, create-like many monks of the medieval period-references not found in canonical texts by using an intricate web of equivalences and associations.
However, this does not mean that Shunkai's arguments would be universally accepted later on. In his next section, on Apocrypha (Gisho no koto 偽書事, ms. 477-478), Shunkai proceeds in a similar manner with a series of texts seen as forgeries already in Yūkai's work. Most of these texts are related to the Sanbō'in lineage of Daigoji, like the Enmanshō 円満抄, the Gayūshi 我友之, the Rokugatsushō 六月抄, and the Sekishitsu 石室. His rhetoric is fairly similar to what can be found in the Mōsho jahō jagishō mokuroku 謀書邪法邪義抄目録, which was most certainly inspired by this text (Rappo 2018. Shunkai's criticism of these texts-and especially the Gayūshi 我友之 (on this text, see Chinen 1997)-saw him rebuked in return by one of the rare defenders of such work, the monk In'yū 印融 (1439-1515), in his Sho'injin kuketsu 諸印信口決, a text compiled shortly after 1478. 18 His argument portrays both Shunkai and Yūkai as liars who cannot be trusted: "Shunkai's attachment to the idea of attacking the other to assert one's own position knows no bounds. In fact, he describes all the texts he did not receive a transmission of as forgeries. They (Yūkai and Shunkai) are the epitome of narrow-mindedness. Their work should not be used at all. This needs to be evaluated carefully from now on". (Zokushingonshū zensho kankōkai 続真言宗全書刊行会 1985, p. 487).
Later sources on the subject, such as the Mōsho jahō jagishō mokuroku, tend to follow in Yūkai and Shunkai's footsteps by depicting such texts as apocrypha, and sometimes as heretical. This suggests that In'yū rebuttal was not really followed and that it became at odds with what would become the leading discourse in the later Shingon school. While it is possible that Shunkai himself was confronted by members of the branch of the Sanbō'in lineage related to Monkan or In'yū, there is no mention of such actual rivalries in the Shingishō. In fact, this text is more about refuting a certain idea of heresy, not necessarily linked to contemporary concerns, in order to establish an orthodoxy and a legitimacy.

Conclusions
In his book, Ginzburg gives the following assessment on the meaning of Menocchio's trials: "This renewed effort to achieve hegemony took various forms in different parts of Europe, but the evangelization of the countryside by the Jesuits and the capillary religious organization based on the family, achieved by the Protestant churches, can be traced to a single current. In terms of repression, the intensification of witchcraft trials and the rigid control over such marginal groups as vagabonds and gypsies corresponded to it. Menocchio's case should be seen against this background of repression and effacement of popular culture". (Ginzburg 1982, p. 126).
Can the same be said about Shunkai and his predecessors? The Shingishō does contain a certain view of countryside as a liminal space where morals and rules are loose and strange ideas are born and spread more easily. In fact, the very origin of the Tachikawa lineage according to later texts is the combination of Shingon Esotericism with Onmyōdō-like concepts in the then-remote province of Mushashi.
Through his insistence on his own pedigree as the inheritor of several genuine lineages from reputable masters, Shunkai thus clearly poses an opposition between true teaching and ideas of dubious origins. However, describing such teachings as popular is dangerous since most of the proponents of what was seen later as heresy, such as Monkan (and the Miwa lineage), were deeply connected to the very religious centers he relies on. This does not mean, however, that discourses on liminality did not exist or did not matter. Historians such as Amino Yoshihiko have amply shown the symbolic and concrete impact of such populations in the course of Japanese history (Amino 1978(Amino , 1986.
This micro-history of Shunkai has shown how the dynamics at work in this process were far more nuanced and the boundaries not as firm as one might imagine. In fact, such discourses, while truly based on certain ideas of what proper Shingon practice should be, were not set in stone and could evolve with the circumstances, while also keeping a few core features, such as the emphasis on lineage, a certain refusal of explicit sexual imagery, and the identification of certain key figures, such as Monkan, as major heretics. Shunkai's own education, and the fact that he learned with Yūkai and others related to the figures accused of heresy also suggests the importance of personal relations and how they could both increase or mitigate such conflicts.
Shunkai was, however, not an imitator of his predecessor. Yūkai's Hōkyōshō was convincingly shown to be quite manipulative, or at least vague enough to avoid direct confrontation (Iyanaga 2010). Contrary to his model, Shunkai does seem to at least try to provide firmer grounds to his accusations, especially against Monkan. Moreover, Shunkai can be seen as a monk with sincere concerns about the practice of proper Shingon Esotericism in the remote area he originally came from, showcasing his careful balancing between ideal rules coming from the center and accommodations to local realities.
This pattern can also be seen in the longer history of Japanese Buddhism with the gradual appearance of a certain orthodoxy in Shingon, but also within Japanese Buddhism. Following Kuroda Toshio's kenmitsu taisei concept, it is commonly admitted that the influence of Esoteric Buddhism, and especially Shingon, culminated in the late Heian and the early medieval period, before being gradually replaced by Zen. This view is not necessarily mistaken but should be counterbalanced with an acknowledgement that Esoteric entered a phase of great expansion and relative popularization during the Muromachi period, especially in northern Japan. Shunkai's work, and his insistence on heresy in the Shingishō, can be seen as the result of the struggles of a monk who was actively very successful in spreading his teaching in the northern Kantō region.

Conflicts of Interest:
The author declares no conflict of interest.
Notes 1 A notable exception is the trial of a few of Hōnen's disciples, but it was not something comparable to the inquisition. See Rappo (2020).