

That paragraph begins,
Like his predecessor critics of artificial intelligence, Taube, Dreyfus and Lighthill, Weizenbaum is impatient, implying that if the problem hasn’t been solved in twenty years, it is lime to give up.
Weizenbaum replies,
I do not say and I do not believe that “if the problem hasn’t been solved in twenty years, we should give up”. I say (p. 198) " . . . it would be wrong . . . to make impossibility arguments about what computers can do entirely on the grounds of our present ignorance". That is quite the opposite of what McCarthy charges me with saying.
It’s a snidely jokey response to an argument that Weizenbaum didn’t make!
From page 202: