PG: "It seems to me that there have been two really clean, consistent models of programming so far: the C model and the Lisp model. These two seem points of high ground, with swampy lowlands between them."

We lost founders of both in the last couple weeks. Ritchie for C, McCarthy for Lisp.

What's cool about the paper Paul is talking about here: if you start with car, cdr, cons, quote, cond, atom, eq, and a notation for functions expressed as lists, you can write an "eval" function reimplementing the language. The rest can be built on top of it.

Graham calls this an "axiomatization of computation". The notion of a Turing machine was already well known before McCarthy's paper, and is its own fundamental description of computation. Then came this high-level language which constitues a new one. It isn't "THE axiomatization of computation", just "AN axiomatization of computation".

PG continues the story in a later essay, "Revenge of the Nerds":

"What happened next was that, some time in late 1958, Steve Russell, one of McCarthy's grad students, looked at this definition of eval and realized that if he translated it into machine language, the result would be a Lisp interpreter."

"This was a big surprise at the time. Here is what McCarthy said about it later in an interview:"

"'Steve Russell said, look, why don't I program this eval..., and I said to him, ho, ho, you're confusing theory with practice, this eval is intended for reading, not for computing. But he went ahead and did it. That is, he compiled the eval in my paper into [IBM] 704 machine code, fixing bugs, and then advertised this as a Lisp interpreter, which it certainly was. So at that point Lisp had essentially the form that it has today....'"

"Suddenly, in a matter of weeks I think, McCarthy found his theoretical exercise transformed into an actual programming language-- and a more powerful one than he had intended."

http://www.paulgraham.com/icad.html

Pretty cool story :)