"This Side of Paradise" is the twenty-fourth episode of the first season of the American science fiction television series Star Trek.

Written by D. C. Fontana and Jerry Sohl (using the pseudonym Nathan Butler) and directed by Ralph Senensky, it was first broadcast on March 2, 1967.

Captain Kirk, First Officer Spock, Chief Medical Officer Leonard McCoy, and others beam down to the colony, and discover the colonists all alive and well, a surprise since the planet is bathed in Berthold rays, a form of radiation which humans cannot survive for longer than a week; the colonists arrived three years previously.

The flowers expel spores that cover Spock, after which he professes his love for Kalomi, and blithely disregards orders to begin the evacuation of the colony.

As part of a symbiotic relationship with their human hosts, the spores provide perfect health, including protection from Berthold rays.

Kirk returns to the ship while the rest of its crew, under the influence of spore plants that have been brought on board, beam down to the planet.

The idea of living in peace and limiting work activities to only the essentials was (and still is, in many respects) contrary to the religious and political ideologies and realities of that era.

The strong Protestant work-ethic present in American society meant a constant strive for development and dominance over nature, no matter the cost.

[10] They note this episode for featuring a romance of sorts between Spock and an inhabitant of the planet Omicron Ceti III.

[11] A 2018 Star Trek binge-watching guide by Den of Geek recommended this episode for featuring the trio of characters Kirk, Spock, and Bones of the original series.