"Plato's Stepchildren" ties the ideals of culture and civilization to TOS's oft-repeated theme that the exertions of mankind are necessary to secure his incorruptibility. As in "The Apple," "This Side of Paradise," and others, humans weren't meant for paradise. (This episode also shares more than just a common background with "Who Mourns For Adonais?" and it's interesting to compare the two.) The thoughtful script winds its way alternating brutality and nuance to the exciting climactic sequence, although the psychokinetic effects of kironide (like the hyperacceleration of Scalosian water) seems to evade notice as a safe yet tremendous weapon. This show also features one of television's most famous kisses (though it contains two for amorous Trekkers counting Spock and Christine).

The subtle strength of the episode is bolstered by excellent acting from the guest stars. Michael Dunn exhibits a talented and memorable performance as Alexander, tirelessly enduring century after century of abuse yet retaining his "humanity" throughout. Liam Sullivan as Parmen and Barbara Babcock as Philana do their despicable best as corporeal corruptions of Truth and Beauty that emerge from her cold remarks and his detestability. And don't overlook the performances of the primaries either, particularly Nimoy cup-busting his way out of catatonia after Parmen's rape of Kirk and Spock.

Parts of the story don't withstand close scrutiny. Far fewer than 38 "academicians" are ever shown, where are the others? Only those escaped the Sahndara nova? Did their power simultaneously enhance their longevity? (Have they ever changed their clothes in over two thousand years?) The eugenics cited by Philana might completely explain their longevity yet if so, was Alexander a product of that? There're also some annoying anachronisms, like "Cupid's" arrow (not Eros?) and odd cites from Lewis Carroll and Shakespeare in their puppet dances. (Could that have been forced from their minds? There's not much to support that, but little else to explain them either.)

Fortunately the compelling conflict in the episode keeps these from dominating the topic. Also deserving commendation are the wonderful effects involved in floating objects around long before CGI rendered such trivial. And if nothing else, one of the all time great Trek lines redeems this episode. An uncertain Alexander asks about life beyond Platonius to which Kirk reassures him that where he comes from, "size, shape, or color makes no difference." That's by and large the important lesson that underscores the entire philosophy of Star Trek. For it to appear as the intellectual antidote to the "bitter dregs" of the Platonians' view, is extra sweet.