I very much enjoyed David Berlinski's discussion of the "stranglehold" that Karl Popper's notion of falsifiability has had on the sciences. Indeed, one might venture to say that the inability of Popper's criteria to handle, as Berlinski puts it, "some very, very simple sentences" is indicative of problems with Popper that stretch beyond the natural sciences.
In a letter from April 10, 1950, Strauss wrote to Voegelin:
May I ask you [Voegelin] to let me know sometime what you think of Mr. Popper. He gave a lecture here [at the New School for Social Research], on the task of social philosophy, that was beneath contempt: it was the most washed-out, lifeless positivism trying to whistle in the dark, linked to a complete inability to think "rationally," although it passed itself off as "rationalism" -- it was very bad. I cannot imagine that such a man ever wrote something worthwhile reading, and yet it appears to be a professional duty to become familiar with his productions. Could you say something to me about that -- if you wish. I will keep it to myself.
Strauss is never so blunt about someone being so terrible in anything that I have read. These words are the harshest I have ever read Strauss write about anyone, which makes these words have even more emphasis.
A few days later, Voegelin replied with a devastating summary of the waste of time he felt in reading Popper. In turn, Strauss replies that he had shown Voegelin's letter to Kurt Riezler, "who was thereby encouraged to throw his not inconsiderable influence into the balance against Popper's probable appointment here. You hereby helped to prevent a scandal." It is remarkable that Strauss moved immediately to stop Popper's appointment to the university.
Voegelin to Strauss:
Dear Mr. Strauss,
The opportunity to speak a few deeply felt words about Karl Popper to a kindred soul is too golden to endure a long delay. This Popper has been for years, not exactly a stone against which one stumbles, but a troublesome pebble that I must continually nudge from the path, in that he is constantly pushed upon me by people who insist that his work on the “open society and its enemies” is one of the social science masterpieces of our times. This insistence persuaded me to read the work even though I would otherwise not have touched it. You are quite right to say that it is a vocational duty to make ourselves familiar with the ideas of such a work when they lie in our field; I would hold out against this duty the other vocational duty, not to write and to publish such a work. In that Popper violated this elementary vocational duty and stole several hours of my lifetime, which I devoted in fulfilling my vocational duty, I feel completely justified in saying without reservation that this book is impudent, dilettantish cr*p. Every single sentence is a scandal, but it is still possible to lift out a few main annoyances.