He's quoting Hickey out of context to try and make it look like Hickey is either ignorant or dishonest about what a type spec like "a -> a" means. In context, H

He's quoting Hickey out of context to try and make it look like Hickey is either ignorant or dishonest about what a type spec like "a -> a" means. In context, Hickey is using hyperbole to emphasize how little information is actually conveyed by a type spec, and explain why he decided to leave types out of Clojure. Thomas' rant is grossly unfair to Hickey, and does a great disservice to the programming community, especially considering the explorations Hickey is currently doing with regards to Clojure spec.