What are some of the major and minor themes of The Chrysalids?
The overriding thematic concern in The Chrysalids (1955) is Wyndham's concern that humankind is not equipped to contend with and triumph through the changes facing the world during, and now after, his time (1903-1969), having lived through both World War I and II. He perceived that humankind's necessary and valuable adherence to rational logic would paradoxically (i.e., seemingly contradictorably) be the undoing of the society rationality had built and was attempting (with debatable success after two world wars) to hold together. He perceived that the only thing that would aid humanity was a collective enlightenment for the need of transcendence of the rigid adherence to old modes of thought and reasoning.
Wyndham illustrates this very vividly by choosing images and philosophical views that were widely familiar and dearly clung to. These were Christianity's religious tenets and paranormal extrasensory perception. Both systems of thought and belief bring up strong ideological and emotional response, especially in the 1950s, in readers who, generally speaking, would have viewed the disparagement of religiousness and advocacy of thought communication as shocking and scandalous. All the better to make his thematic point, which is that "the essential quality of living is change" and therefore humanity needs to embrace change and each other as though no separation "existed any more," as though "for a time there was a single being that was" all.
The society that exists in this story is one full of fear and prejudice. The people live their lives according to the Old Testament of the Bible, not allowing for anyone or anything that is not normal according to their own strict guidelines. These rural denizens live by such commandments as "blessed is the norm" and "watch thou for the mutant". Anyone who isn't like them is exterminated, and many of these "mutants" have fled to the Fringes, a place outside of Labrador, the community of the "norms".
The central themes are that society must get rid of its enslavement to the past and its fears and prejudices, and humankind must unite in order to save themselves from total annihilation. The novel suggests that by following religious beliefs, we have dehumanized our society because we blindly follow outdated Biblical laws that don't allow for differences. Those in control use the Old Testament to support their prejudices toward anyone who is different. Change isn't acceptable because that would involve straying from the Biblical laws that stereotype people. The author tells us that we are all "mutants" in one way or another, and this is what we must realize unites us as humans. Unless we can get beyond our stereotypical prejudices, we are doomed.