Fun Theory is the field of knowledge studying how to design for fun in future society: it deals in questions such as "How much fun is there in the universe?", "Will we ever run out of fun?", "Are we having fun yet?" and "Could we be having more fun?"
From The Fun Theory Sequence:
Many critics (including George Orwell) have commented on the inability of authors to imagine Utopias where anyone would actually want to live. If no one can imagine a Future where anyone would want to live, that may drain off motivation to work on the project. The prospect of endless boredom is routinely fielded by conservatives as a knockdown argument against research on lifespan extension, against cryonics, against all transhumanism, and occasionally against the entire Enlightenment ideal of a better future.
Fun Theory is also the fully general reply to religious theodicy (attempts to justify why God permits evil). Our present world has flaws even from the standpoint of such eudaimonic considerations as freedom, personal responsibility, and self-reliance. Fun Theory tries to describe the dimensions along which a benevolently designed world can and should be optimized, and our present world is clearly not the result of such optimization. Fun Theory also highlights the flaws of any particular religion's perfect afterlife - you wouldn't want to go to their Heaven.
Some critiques of transhumanism (and related fields such as cryonics or lifespan extension) suggest that human enhancement would be accompanied boredom and the end of fun as we know it. For example: "if we self-improve human minds to extreme levels of intelligence, all challenges known today may bore us." Likewise, "if superhumanly intelligent machines take care of our every need, it is apparent that no challenges nor fun will remain."
However, we can work towards determining whether and how the universe will offer, or whether we ourselves can create, ever more complex and sophisticated opportunities to delight, entertain and challenge ever more powerful and resourceful minds.
Transhumanists are usually seen as working towards a better human future. This future is sometimes conceptualized, as George Orwell aptly describes it, as Utopia:
"It is a commonplace [view] that the Christian Heaven, as usually portrayed, would attract nobody. Almost all Christian writers dealing with Heaven either say frankly that it is indescribable or conjure up a vague picture of gold, precious stones, and the endless singing of hymns... [W]hat it could not do was to describe a condition in which the ordinary human being actively wanted to be."
Imagining this perfect future where every problem is solved and where there is constant peace and rest--as seen, a close parallel to several religious Heavens--rapidly leads to the conclusion that no one would actually want to live there.
A key insight of fun theory, in its current embryonic form, is that eudaimonia - the classical framework where happiness is the ultimate human goal - is complicated. That is, there are many properties which contribute to a life worth living. We humans require many things to experience a fulfilled life: Aesthetic stimulation, pleasure, love, social interaction, learning, challenge, and much more.
It is a common mistake in discussion of future society to extract only one element of the human preferences and advocate that it alone be maximized. This would neglect all other human values. For example, if we simply optimize for pleasure or happiness, "wirehead", we'll stimulate the relevant parts of our brain and experience bliss for eternity, but pursue no other experiences. If almost any element of our value system is absent, then the human future will likely be very unpleasant.
Enhanced humans are also seen to have the value system of humans today, but we may choose to change it as we self-enhance. We may want to alter our own value system, by eliminating values, like bloodlust, which on reflection we wish were absent. But there are many values which we, on reflection, want to keep, and since we humans have no basis for a value system other than our current value system, fun theory must seek to maximize the value system that we have, rather than inventing new values.
Fun theory thus seeks to let us keep our curiosity and love of learning intact, while preventing the extremes of boredom possible in a transhuman future if our strongly boosted intellects have exhausted all challenges. More broadly, fun theory seeks to allow humanity to enjoy life when all needs are easily satisfied and avoid the fall into the un-fun utopian futures in literature.