Step-by-step explanation:
Since Dr. Jekill's mind was so constrained into the role of applying all its knowledge for the benefits of society it is possible that the autor impersonnated all the possible other meanings of one's deeds in a character such as Mr. Hyde.
Whether a real case or just a psichological symbol ( like the step mother in Snow-white or the uses of nitroglicerine) it is quite an impressive story