I have read your letter very carefully.
In your question about the teaching, you state that at the point of the awakening of the one moment of shinjin we are grasped and protected by the heart of unhindered light, and hence the karmic cause for birth in the Pure Land is established in ordinary times. This is truly splendid. Yet, though what you state is splendid, I am afraid that it has become nothing but your own calculation. Once you have come simply to believe that it surpasses conceptual understanding, there should be no struggle to reason it out.
You also write that there are people who say, “My aspiration to transcend this world is great, but slight is the karmic cause for my birth in the Pure Land.” This is impossible to accept. The aspiration to transcend this world and the karmic cause for birth in the Pure Land are one and the same. I consider these words to be, in their entirety, needless calculation. If you realize that the wisdom of the Buddhas surpasses conceptual understanding, there should not, in addition, be any calculating. You simply should not fall into doubts over the different things that people say. Simply give yourself up to Tathagata’s Vow; avoid calculating in any way.
Respectfully.
Fifth month, 5th day
Shinran
To Joshin-bo:
Other Power means to be free of any form of calculation.