"Functional programming" is a term with a few meanings. Notably, the paper that (I believe) coined the term, "Can Programming be Liberated from the Von Neumann

"Functional programming" is a term with a few meanings. Notably, the paper that (I believe) coined the term, "Can Programming be Liberated from the Von Neumann Style?" by John Backus, spent a fair amount of ink on specifically calling lisp out, and contrasting it from what he had in mind. IIRC, he felt that FP was preferable to the lisp model because lisp gives you too much power: Mutable variables, ways of composing functions that are potentially more error prone due to domain/range mismatch gotchas, stuff like that could all be impediments to ensuring the correctness of programs. I think that, to some extent, a sort of Haskellian fastidiousness about correctness is what he felt this proposed functional style of programming was all about.