Good vs. evil: Are they truly separate?

Every human being has both in them good, and evil. It is a basic element of the human character. We all have it. This is explained by Dr. Jekyll in his final letter to Mr. Utterson. However it is explained that Mr. Hyde does not have good and evil within him, but only evil "...Edward Hyde, alone in the ranks of mankind, was pure evil." This is reason which Jekyll gives for the fact that everyone who encounters Mr. Hyde is repulsed by his appearance. The first question I would then like to bring up, is since Mr. Hyde is pure evil, can we qualify him as a human being? As he is often described as being deformed, and obscure. Going back to the beginning where Me. Utterson first encounters Mr. Hyde we fin the description as being "hellish to see, it wasn't like a man; it was like some damned Juggernaut." And again further down on the page;"...I could see that but carrying it off, sir, really like Satan." Thus I see an argument to be made that this deformed version of Dr. Jekyll is not truly human in a the true since of the word, but more of a demon or devil like creature. However if this creature is not human how shall we define it, and is it truly a separate entity form Dr. Jekyll, or is he simply the evil side of Jekyll? Jekyll initially describes the transformation as being the seperation of his evil half from his whole self in hope that his good half will be free from the other. Yet it does not mean to entities or different people, but simply the separation of the elements that make up that person. For when he first goes under the transformation he identifies that he still feels natural and like his own self. He says "...I was conscious of no repugnance, rather of a leaps of welcome. This, too, was myself." This we see that Jekyll identifies Mr. Hyde as being a natural part of himself. So my question is, is Dr. Jekyll equally quilts of the crimes committed as Mr. Hyde, or is Mr. Hyde truly a deferent independent individual created by dr. Jekyll? The argument could be made for both, for as the letter goes on we see that Jekyll explains how Hyde and Jekyll really do become two differentials each searching for a different goal which eventually drives them against each other. However I tend to see Jekyll responsible for the actions of Hyde, much in the same way that Frankenstein is responsible for the monster he created. 1. Is Mr. Hyde a human being or a creation of science? 2. Are Mr. Hyde and Dr. Jekyll really to different and independent people each with their own will and conscience or are they simply different parts of one whole?