What is the difference between Lisp-1 and Lisp-2?

I have tried to understand the difference between Lisp-1 and Lisp-2 and how this relates to Clojure but I still do not understand properly. Can anyone enlighten me?


  • According to wikipedia:

    Whether a separate namespace for functions is an advantage is a source of contention in the Lisp community. It is usually referred to as the Lisp-1 vs. Lisp-2 debate. Lisp-1 refers to Scheme's model and Lisp-2 refers to Common Lisp's model.

    It's basically about whether variables and functions can have the same name without clashing. Clojure is a Lisp-1 meaning that it does not allow the same name to be used for a function and a variable simultaneously.