[sek]

Lisp is one of the oldest programming languages developed in the 1960, it came before and is very elegant actually. You can write incredibly powerful things with this pattern and it's also really simple to build an interpreter for it with the stuff they had at their disposal at the time.

[baq]

See also: 'Recursive Functions of Symbolic Expressions and Their Computation by Machine' (1960) [1]

[1] https://www-formal.stanford.edu/jmc/recursive.pdf