There is a story circulating about R. Yisrael Meir Kagan (the Chafetz Chaim) that he disparaged R. Avraham Yitzchak Kook as "Kook Shmook", apparently dismissing him as a wayward scholar if not worse. While this story is so blatantly false that it needs no refutation, I felt that people would benefit from the following two stories about the Chafetz Chaim and Rav Kook. The first is how offended the Chafetz Chaim became when someone disparaged Rav Kook and the second is only slightly related but interesting -- how Rav Kook wrote a haskamah (approbation) for one of the Chafetz Chaim's books. Both are taken from Simcha Raz's biography of Rav Kook, An Angel Among Men (if you are interested in buying this book, please buy it from this link as an experiment to see the power of a Hirhurim link. thank you.).
Holy and PureP. 368:
The zealots who defamed the Rav [Rav Kook], criticized his writings and ways of conduct, attempted to bring their slanderous reports to R. Yisrael Meir HaKohen Kagan, the famed Chafetz Chayim. In keeping with his aversion to lashon ha'ra (slander), the Chafetz Chayim refused to listen to their words. And when he received libelous material about Rav Kook in the mail, he thrust it aside contemptuously, without even opening it.
In 5683 (1923), Agudat Yisrael held its first K'nessiyah Gedolah (Great Assembly) in Vienna. The greatest Torah scholars and chassidic masters of the time came from all over Eastern Europe to discuss important issues facing the Jewish world. Among the gedolim in attendance was the Chafetz Chayim. A delegation from the Eretz Yisrael branch of Agudat Yisrael came as well.
At the opening session of the conference, one of the rabbis made an insulting comment about Rav Kook. Utterly shocked, the Chafetz Chayim, who was sitting at the dais, stood up and said, "They denigrated the Rabbi of Eretz Yisrael! We should rend our garments!" He then left the room in protest.
The Chafetz Chayim decided not to participate in the rest of the conference. He simply stayed in his hotel room and waited to return home with the other rabbis from Poland. Anyone who wanted to speak to him or receive his blessing had to visit him in his room.
One day, the members of Jerusalem's delegation came to receive a blessing from the venerable sage. The Chafetz Chayim, however, refused to extend them his hand, saying, "I do not give Shalom ('Peace') to those who stir controversy against the Rabbi of Jersualem." Then he added, "You should know that he is holy and pure, and whoever harms him will not be absolved."
A Worthy ApprobationSee also this post.
R. Refa'el HaKohen Kook related:
When the Chafetz Chayim zt'"l finished writing Nidchei Yisrael, he came to the Aderet (R. Eliyahu David Rabinowitz-Te'omim) to receive a letter of approbation for the book.
The Aderet kept the book's proof sheets in order to look though them before writing the approbation. Unfortunately, however, he came down with pneumonia and was quite ill for several weeks. During that time, the Chafetz Chayim came back to receive the approbation he so anxiously waited for. The Aderet's doctor, however, forbade him to exert himself in any way; so he was unable to write the letter.
The Chafetz Chayim was very disappointed, having made the trip just for the approbation. "Don't worry," said the Aderet, "I just married off my daughter to R. Avraham Yitzchak HaKohen Kook, who is greater than me in many areas. He will write the letter, and I will sign it."
And so it was: The Rav [Rav Kook] wrote an approbation for Nidchei Yisrael and the Aderet signed it, thus forging a strong bond of friendship between the Chafetz Chayim and Rav Kook.