Usually yes. To distinguish between lists and function calls. However if we are to pass code literals to eval, we need to quote them:

    =>(eval '(1 2 3))
    Cannot call 1 as a function.
    =>(eval ''(1 2 3))
    (1 2 3)

You're basically asking if literals are code. I imagine you'll get varied opinions about that.

(And yes, that can be used unquoted in a few different contexts in Lisp, such as a special form or macro, or if you've managed to convince the reader that 1 is a function.)