Editing Robert A. Heinlein (section)

===Middle period work, 1961–1973===
[[File:If 196211.jpg|thumb|upright|Heinlein's novel ''Podkayne of Mars'' was serialized in ''[[If (magazine)|If]]'', with a cover by [[Virgil Finlay]].]]
From about 1961 (''[[Stranger in a Strange Land]]'') to 1973 (''Time Enough for Love''), Heinlein explored some of his most important themes, such as [[individualism]], [[Libertarianism in the United States|libertarianism]], and free expression of physical and emotional love. Three novels from this period, ''Stranger in a Strange Land'', ''[[The Moon Is a Harsh Mistress]]'', and ''Time Enough for Love'', won the [[Libertarian Futurist Society]]'s [[Prometheus Hall of Fame Award]], designed to honor classic libertarian fiction.<ref>{{cite web|url=http://www.lfs.org/awards.htm|title=Libertarian Futurist Society|website=Lfs.org|access-date=November 26, 2017|archive-date=June 28, 2011|archive-url=https://web.archive.org/web/20110628180047/http://www.lfs.org/awards.htm|url-status=live}}</ref> Jeff Riggenbach described ''The Moon Is a Harsh Mistress'' as "unquestionably one of the three or four most influential libertarian novels of the last century".<ref name=Riggenbach>{{cite journal|last=Riggenbach|first=Jeff|title=Was Robert A. Heinlein a Libertarian?|journal=Mises Daily|publisher=[[Ludwig von Mises Institute]]|date=June 2, 2010|url=https://mises.org/daily/4428/Was-Robert-A-Heinlein-a-Libertarian|access-date=September 13, 2014|archive-date=September 14, 2014|archive-url=https://web.archive.org/web/20140914002124/https://mises.org/daily/4428/Was-Robert-A-Heinlein-a-Libertarian|url-status=live}}</ref>

Heinlein did not publish ''Stranger in a Strange Land'' until some time after it was written, and the themes of free love and radical [[individualism]] are prominently featured in his long-unpublished first novel, ''For Us, the Living: A Comedy of Customs''.

''The Moon Is a Harsh Mistress'' tells of a war of independence waged by the Lunar penal colonies, with significant comments from a major character, Professor La Paz, regarding the threat posed by government to individual freedom.

Although Heinlein had previously written a few short stories in the [[fantasy]] genre, during this period he wrote his first fantasy novel, ''[[Glory Road (Heinlein novel)|Glory Road]]''. In ''Stranger in a Strange Land'' and ''[[I Will Fear No Evil]]'', he began to mix hard science with fantasy, mysticism, and satire of organized religion. Critics William H. Patterson, Jr., and Andrew Thornton believe that this is simply an expression of Heinlein's longstanding philosophical opposition to [[Positivism (philosophy)|positivism]].<ref>{{Cite book |last=Patterson |first=William H. |url=https://www.google.com/books/edition/The_Martian_Named_Smith/BZkrAQAAIAAJ?hl=en&gbpv=1&bsq=Heinlein+positivism+Thornton&dq=Heinlein+positivism+Thornton&printsec=frontcover |title=The Martian Named Smith: Critical Perspectives on Robert A. Heinlein's Stranger in a Strange Land |last2=Thornton |first2=Andrew |date=2001 |publisher=Nitrosyncretic Press |isbn=978-0-9679874-2-2 |pages=129 |language=en}}</ref> Heinlein stated that he was influenced by [[James Branch Cabell]] in taking this new literary direction. The penultimate novel of this period, ''I Will Fear No Evil'', is according to critic James Gifford "almost universally regarded as a literary failure"<ref>Gifford, James. ''Robert A. Heinlein: A Reader's Companion'', Nitrosyncretic Press, Sacramento, California, 2000, p. 102.</ref> and he attributes its shortcomings to Heinlein's near-death from [[peritonitis]].