Post-Civilization? II

The Foreword to James Blish's Mission To The Heart Stars (London, 1980) mentions several illustrious predecessors in the field of sociological science fiction (sf):

HG Wells;
Aldous Huxley;
L Sprague de Camp;
magazine since fiction since 1926.

Mission To The Heart Stars is a worthy successor of The Shape Of Things To Come, Brave New World, Lest Darkness Fall etc. In fact, in some ways, it has more going for it:

hard sf, based on knowledge of cosmology (kinds of galaxies) and on speculation about negative entropy in electromagnetic fields;
juvenile sf;
two imaginary societies, the Heart Stars federation and the future Earth;
in fact, three if we count the energy beings, or "Angels," whose harmonious relationships mortals might aspire to emulate.

The energy beings are speculative sf. Interaction between a (relatively) young Angel and the juvenile hero plus the latter's maturation constitute juvenile fiction. In addition, Blish, like Wells and Huxley, discusses the future of humanity in technological society. Having dramatized several relevant issues, Blish does not need to pursue any further his fictional history of conflict between the UN-Angels alliance and the Heart Stars. The "Malans" make good villains but we do not need any sequels showing us Terrestrial heroes fighting the Hegemony of Malis.

(Dr Langer tells one Malan, "'...we bear you no malice personally.'" (p. 109)

(- thus giving away the pun between "Malis" and "malice.")