The thing about
science fiction, for me at least, is often the setting of the piece. This is why I have always liked
Zardoz.
The core of the place is a crystal, light, computer called the Eternal Tabernacle. Each Eternal, for the main characters live eternally, have a ring with a crystal which, through the computer, joins them to every other. They also have a small crystal in their foreheads which also connect them--especially in, so-called, second order meditation, which has taken the place of sleep, and dreaming.
Groups of Eternals live in smallish communities called Vorticies where they produce various things that are exchanged with other Vorticies. The Eternal Tabernacle periodically lists surpluses and requirements of each Vortex.
In this perfect society the Eternals pursue artistic, literary, and scientific interests with the assistance of the light computer, and those others as would like to join.
It was the image of a circle of Eternals in second level meditation, casting out a renegade that kept drawing me to the movie.
Now the look of the movie, as well as everything else about it, is from the imagination of John Boorman who wrote, produced, and directed it.
Possibly a bad movie, as suggested above, but in the 15 or more years since it was produced, light computers are now not a fantasy. A team at the University of Toronto this spring created/discovered a crystal that manipulates light the way silicon manipulates electricity.
Just another example of the way the human imagination anticipates the scientific intellect.
Later addenda
The flying head is manned by one Arthur Friend who, under the influence of the Eternal Tabernacle, begins the experiments in genetic selection which result in the birth of the Sean Connery character.
The entire religion of Zardoz was established to bring death to the Eternals. Clone's quote is part of it. The change of the exterminators' job from killing those on the outside, to making them plant and grow food is part of it. Hence the tribute to be placed in the flying head.
Th tribute is needed because the Eternals are afflicted with an overwhelming apathy, and cannot provide for themselves. This is the consequence of immortality. Hence the religion that Arthur Friend creates.
The only question: Who really is the man behind the curtain? Is it Arthur, who thinks he is. Or the Eternal Tabernacle as the Connery character, which has the greater intellect, concludes.