This review will contain spoilers!
In many sentences:
Kokoro, according to the foreword by the translator, is best translated as "the heart of things". In many ways, this seems fitting for this book. From the beginning, when the narrator meets Sensei for the first time and begins to develop a friendship, we get an honest insight into their relationship. There are multiple times where the narrator is stricken with a sense of sadness or depression when Sensei speaks to him coldly, or is unable to remember who he is. It reminded me very clearly of those times where you are unaware of your position in a relationship or how the other person feels about you. Thus, every word or gesture carries greater meaning, even if it is not purposeful. Soseki's ability to capture this feeling is excellent.
In addition to honestly capturing a burgeoning relationship, Soseki also attempts to get at the heart of things through the conversations of Sensei and our narrator (and later, via Sensei's letter). For example, once when trying to warn the narrator, Sensei says "I bear with my loneliness now, in order to avoid greater loneliness in the years ahead. You see, loneliness is the price we have to pay for being born in this modern age, so full of freedom, independence, and our own egotistical selves" (24). Obviously, this is also Sensei's self-inflicted punishment for his treatment of K, but I think there is further insight here into the way culture has changed as we have become more modern (which is particularly interesting considering it was evident in early 20th century Japan, as well).
Another moment that I felt was accurately captured was when K and Sensei begin living together, and Sensei reflects on how their friendship now is defined by the boundaries established when it was initially formed (p 150). As a result, they were not able to easily discuss the subject of love (and of course, much heartache may have been avoided had then been able to discuss it more openly). Sadly, this observation is true, and redefining a long term friendship can be difficult (though not impossible).
Ultimately, it is worth reading Kokoro if you want to read a book that will delve deeply and honestly into friendship, love, trust, and honor. It is not always pleasant, and I don't always agree with what Soseki is trying to say, but on the whole it is interesting. It should also be noted that in terms of quality, this book is extremely well written. There is a clear and obvious difference between the short, simple, honest sentences of the narrator in the beginning and the deeper, more complicated thought process of Sensei in the letter. Not once did I find myself confused about who was speaking - in many ways it felt almost as though the letter were an entirely different book. This strikes me as a difficult effect to achieve, and Soseki's ability to do it so completely is impressive.
As a final note, I found it particularly interesting that in the story of the love triangle between Sense, K, and the daughter, we are given an honest account of the events by the one who betrayed his friend to get the girl. It seems that literature typically gives us account of the one who is hurt and betrayed, and not of the one who acts cruelly out of selfish desire. It was, while not fun or pleasant, a unique and interesting experience. "Through cunning, I have won. But as a man, I have lost" (177).
"I believe that words uttered in passion contain a greater living truth than do those words which express thoughts rationally conceived. It is blood that moves the body. Words are not meant to stir the air only: they are capable of moving greater things."Natsume Soseki in Kokoro
Natsume Soseki the First Line of Kokoro
Natsume Soseki the Last Line of in Kokoro