There's another link between Lisp and APL in the article:
"Some years back, we had a visit at Carnegie from a person at MIT
whose name I've forgotten. He started to give us a lecture in a
little office about some programming issues in LISP. He went up to
the blackboard and he spoke LISP. Everything he wanted to
describe, he described in terms of parentheses and CONS and CARS
and CDRS. He found himself quite capable of expressing his ideas
in the language in which he programmed. Not once during the half
hour or so that he lectured to us did I see the inevitable block
diagram, the flow charts that show up on the blackboard with
things written in semi-English. He didn't need them. And at the
time I said to myself, "LISP has a very precious character, if
indeed there are some people who can express programming ideas to
other people in the language in which they program.
"I can't do that with ALGOL; never have I been able to do it with ALGOL.
Whenever I've programmed in ALGOL and I've wished to make some
statements about the program I was writing, I was forced to go
outside the language and use English, or mathematics, or some
block diagrams or what-not.
"In APL, I find that to a far greater
degree than any other language that I've used, I can make
statements about the programs that I'm writing, in APL -- actually
not exactly APL, but APL with some nice little extensions that I
dream up at the moment but would never think of implementing. But
by and large, I find that the language allows me to express
myself, in the language, about the things I'm dealing with. I find
that a very precious property of a programming language."