It means that a programming language should, above all, be malleable. A programming language is for thinking of programs, not for expressing programs you've already thought of. It should be a pencil, not a pen. Static typing would be a fine idea if people actually did write programs the way they taught me to in college. But that's not how any of the hackers I know write programs. We need a language that lets us scribble and smudge and smear, not a language where you have to sit with a teacup of types balanced on your knee and make polite conversation with a strict old aunt of a compiler.

In history--in life--possibilities do not become realities of their own accord; someone, with his hands and his brain, with his labor and his self-sacrifice, must make realities of them. . . . All we are given is possibilities--to make ourselves one thing or another. . . .