I don't know, is it? Are there any specific features that we can point to and say -- "that's a Lisp" and "That's not a Lisp." Or is categorization instead prima

I don't know, is it? Are there any specific features that we can point to and say -- "that's a Lisp" and "That's not a Lisp." Or is categorization instead primarily dependent on pedigree? If so, why do we care? What usefulness is this distinction aside from pedagogical purposes?