Tannisho
The Tannishō (歎異抄), also known as the Lamentations of Divergences, is a late 13th century short Buddhist text generally thought to have been written by Yuien, a disciple of Shinran. In the Tannishō, Yuien is concerned about the rising doctrinal divergences that emerged in Jōdo Shinshū Buddhism after the death of their founder, so he wrote down dialogues between himself and Shinran that he could recall when his master was alive.
According to Yuien's own writing in the preface:[1]
When I reflect with deep humility upon the past and the present, I cannot help but deplore the prevalence of various deviations from the true faith transmitted by word of mouth from our late Master....Therefore I have recorded here the gist of what the late Shinran Shonin told me, while it still reverberates in my ears. This has been written solely to clear away in advance any uncertainties that might arise among fellow devotees. So much by way of foreword.
Many of the conversations found in the Tannishō are candid when compared to more formal religious texts, and this may explain some of the popularity of the Tannishō among Jōdo Shinshū Buddhists. The Tannishō allows Jōdo Shinshū Buddhists to peer into the mind of Shinran and see how he felt about practicing Jōdo Shinshū. The Tannishō was also a major impetus for the start of The Dobokai Movement[2] among the Higashi Hongwanji branch of Jōdo Shinshū.