Peter Dickinson’s success comes from taking a radical idea, keeping it simple, and applying it to very specific situations and plots. By doing so, he is able to draw on the strengths of the traditional quest or flight story, with youthful heroes and heroines showing typical virtues of courage, resourcefulness, perseverance, and sympathy without sidetracking interest too far down a science-fiction bypath.
The main themes of the trilogy fall into psychological and sociological categories. Dickinson shows the effects at general and familial levels of fear, as well as the ways in which individuals and society deal with it: scapegoating (of witches, outsiders, and the mentally retarded); authoritarianism (reversions to patriarchal norms and feudal hierarchy); and ritual (the reemergence of a highly liturgical form of Christianity). Children are shown to have greater resilience than adults and to be much more flexible in their thinking.
At a sociological level, Dickinson depicts a society in chaos and how attempts to restore order are made. By showing how quickly a highly developed civilization disintegrates, he poses searching questions about the depth of Western norms and institutions, both morally and structurally. In his treatment, the hatred of machinery, while basically shown to be harmful, has about it a certain ambivalence. The rustic lifestyle and lack of rush are portrayed almost nostalgically at times.
Of the trilogy, Heartsease is the most carefully written and seems to have a depth that the other two books lack. The final denouement of The Weathermonger reveals the thinness of the supernatural motif in its bathos.
Peter Dickinson wrote for both adults and children. His children’s fiction is entirely fantasy, but the supernatural is rarely taken seriously for itself. Rather, it is a peg on which to hang an often fascinating and complex scenario, as in The Gift (1973), Annerton Pit (1977), and Tulku (1979). This is certainly true of The Changes Trilogy. A number of other children’s fantasies were published just after the trilogy, all concerning the collapse of Western civilization—reflecting, it would seem, a general pessimism about the future of the West. In the United States, one example would be Robert C. O’Brien’s Z for Zachariah (1975), which concerns survivors of a nuclear holocaust. In the United Kingdom, John Christopher’s The Guardians (1970) and The Sword of the Spirits trilogy (1972) cover similar ground. Both Christopher and Dickinson use science fiction as a fantasy mode, but Dickinson moves more toward the “uncanny” in his use of supernaturalism.