Steven Padnick writes:
And when I say everybody, I mean everybody. Not just most people today don’t understand the original story—though that’s true—but every retelling of the story, from the earliest stage plays to Steven Moffat’s otherwise brilliant miniseries Jekyll, misses a key point of Robert Louis Stephenson’s original story:
There is no Mr. Hyde.
Edward Hyde is not a separate personality living in the same body as Henry Jekyll. “Hyde” is just Jekyll, having transformed his body into something unrecognizable, acting on unspecified urges that would be unseemly for someone of his age and social standing in Victorian London (i.e. some combination of violence and sex. Torture is specifically mentioned).
Jekyll did not create a potion to remove the evil parts of his nature. He made a potion that allowed him express his urges without feeling guilty and without any consequences besmirching his good name. That’s also why he names his alter ego “Hyde,” because Hyde is a disguise, to be worn and discarded like a thick cloak. He might as well have called Edward “Mr. Second Skin,” or “Mr. Mask.”
Full Story: Tor.com: What Everybody Gets Wrong About Jekyll and Hyde