The truth is always hard to pin down. This is certainly the case for abstract concepts, such as religion, the meaning of life, and the nature of the universe; however, it is also true of things one would consider objectively verifiable. San Manuel Bueno, Martyr dramatizes this by telling its story through multiple points of view.
To begin, Don Manuel is the eponymous character and the protagonist of San Manuel Bueno, Martyr. As such, the nivola is centered around his actions and his life in Valverde de Lucerna. However, Don Manuel is not the narrator of San Manuel Bueno, Martyr; rather, his character is viewed from the outside perspective of Angela Carballino. Already, we can see that the reader is several steps removed from the primary subject of the nivola.
Angela, a villager of Valverde de Lucerna, is the primary narrator of the nivola; it is through her writing that we learn about the life of Don Manuel. However, the memoir is written nearly thirty years after the death of Don Manuel, at a point when Angela herself admits that her memory has become questionable over time. Can we, the reader, trust the contents of Angela Carballino's memoir? Could Angela hold ulterior, even sinister, motives for writing this memoir? This question hangs over San Manuel Bueno, Martyr.
The issue becomes even trickier when considering the epilogical narrator at the end of the nivola. The epilogical narrator's identity is unknown; while one could surmise that it is Miguel de Unamuno, the author of San Manuel Bueno, Martyr, this is neither confirmed nor denied by the epilogical narrator himself. To make things even more difficult, the narrator confesses that he has made some edits to Angela's memoir. What edits were made? For what purpose? These questions, too, can never be answered. If you are reading in English, consider, finally, the fact that the nivola has been translated from Spanish, and you can see that to try and get to the final, objective truth behind San Manuel Bueno, Martyr is futile.
Why did Unamuno choose to write the nivola in this way, as opposed to simply writing from the first-person perspective of Don Manuel himself? Perhaps, by telling the story of Don Manuel through the filtered perspective of several individuals, Unamuno demonstrates the impossibility of ever discovering the "capital-T Truth" of life. Instead, much like the characters in San Manuel Bueno, Martyr, we must decide for ourselves what we will choose to believe as true.