Image of the letter and a transcription below:
Fallowfield, Manor Road, Penn, Buckinghamshire, England.
April 28th, 1970
Dear Professor Aron,
Many thanks for your letter of April 15th.
I can only say that when I read either Adorno or Habermas, I feel as if lunatics were speaking.
I have translated some of their German sentences into simple German. It turns out to be either trivial or tautological or sheer pretentious nonsense. I completely fail to see why Habermas is reputed to have “talent”. I do not think that he was born less intelligent than other people; but he certainly did not have the good sense to resist the influence of a pretentious, lying, and intelligence destroying University education.
Sociology is in a bad way — even here in England. There seems to be an interesting law: bad and pretentious language drives out good and simple language. And once human language is destroyed, we shall return to the beasts. I have, in fact, written a very brief reply to Adorno-Habermas. I have not published it, but I may one day.
Many thanks again for writing to me.
Yours sincerely,
Professor Sir Karl Popper
Related: Karl Popper on science versus pseudo-science, in the Philosophers, Explained series.
Thank you. Useful to have posted; I googled and found it here.