Flowers for Algernon (1965) [pdf]
I always hated this story.  For me, the underlying theme is one of class and social structure.  The illiterate man is lifted above his situation by science.  He is then hammered back down.  This is a story about how science cannot change the underlying "natural" state of a person.  It is a lesson for scientists about not messing with god-given realities.  I also don't like the linking of one's job to one's intelligence.  The two are rarely directly related.The opposite to Flowers for Algernon is Captain America.  A weak man is improved by science and goes on to be the champion of his nation: Science overcomes nature and God-given limitations can be overcome by government-backed scientific wonders.