Jürgen Habermas in Constellations:
It was nearly 50 years ago when Dick called me for the first time and invited me to come over to Haverford for a discussion. It is not only because of the beginning of our longstanding friendship that I start with that phone call I got in 1972 at the Humanities Center of Cornell University. It moreover led, at this first encounter, to a memorable and rather improbable discovery. The two of us had been brought up on different continents and in different societies, with different backgrounds at different schools and different universities, not to speak of a childhood and youth we spent on opposite sides of a monstrous World War, in which Dick had lost a brother; but in spite of all of these obvious distances in origin and socialization we soon discovered a broad overlap in our philosophical background and also in our present research interests. Hegel, Marx and Kierkegaard, Sartre and existentialism, even Peirce and Dewey and our present research programs in action theory and communication are the catch words to indicate this unexpected convergence of our philosophical orientations. And my surprise was soon confirmed when I read Dick’s book Praxis and Action which I immediately recommended to Suhrkamp for translation.
However, the discovery of these intellectual family bonds is only half of the story; I would not have accepted the invitation to come to Haverford with Ute and our two daughters for a whole term, had Dick not been the impressive personality he indeed was—a host of overwhelming charm and an open-minded, spontaneous and inspiring partner in the ongoing ping-pong of arguments.
More here.