Immortality as a false and futile goal, inevitably bringing stagnation, tedium, and a powerful desire to die. Male potency as a necessary ingredient in a thriving society, bringing great violence, but also sexualty, the will to procreate and the strength to forge progress. One of the finest adaptations of Frankenstein.
Whatever it is, it begins with a mortal storming Heaven and shooting God in the back. Zardoz is a fractured masterpiece of too many heady ideas.