What makes good Fantasy/Scifi?

This is one of those momments, when the long hours have seemingly brought me to some epiphany of a momment. Wherein if not written down may cause the thought to be lost forever.

So whether compete farce or actual possibility here it is. According to every fantasy and science fiction book I've ever read the true object of every book is not to provide entertainment, or to tell a great story... yet to put forth some sort of opinion on a subject. Or to respond to the idea of another author.

Here is where the nerd glasses fit on my head perfectally and I feel confident of wearing that grand title to some degree. The book Dune by Frank Herbert in great measure nothing more then a comment on the Foundation series by Issac Asimov. One writer feeding off another and coming to different conclusions, thus seeking to illustrate thru the medium of a science fiction novel the another veiwpoint of a concept.

It's all about concept, philosiphy and understanding reality, or at least making an attempt to. Then like a good american selling your idea in a fancy sparkly wrapper at proper eye level to the consumer.

Take for instance Homeland by Salvatore, in which a young drow lives in a society of ruthlessness and violence. Yet does not quite seem happy with it. This story is intertwined with multiple levels of communication, the author is not only telling a story of what happened... that would be non-fiction. The author is telling the story from a particular veiwpoint for a particular purpose and communicating with the reader about the idea of the ruthless society. Which comes into a fashionable trend every so many years which is my way of saying I don't like ruthless, sneaky behind your back, societies.

The book is good fantasy... plenty of new wonderfull places to explore in ones imagination while they read. The proper momments of suspense and horror.

Yet what makes good fantasy or science fiction in my late night epiphany seems to be just that... newness, originality, something no one has thought of before in exactly the same way. Yet that's not enough in the end... a good story without any underlying message at least to me seems to fall shorts.

Slip thru the cracks of the floorboards to meet the owner of the throbbing eye in the Tell-Tell heart by Edgar Allen Poe. What is that story really saying and who is it talking about? I think these are the questions that gnaw at you in the late night hours... pumping the brain full of thoughts, that keep the mind sharp and able to face the real world well exercised.

Or in the very least keep me awake having mock little epiphanies, that by morning don't make any sense.