The moral fable was a staple of human mythology long before the invention of written language. While ancient mythic tales can be based on creation, mystery, adventure, tragedy or even romance, the great majority contain at least some modicum of an edifying moral truism at their hearts. This is a consequence of the basic human desire to find some higher meaning behind the characters' actions, whether human or titan. A routine procedure in fables is to provide a "foil" character to reflect the morality of the story's theme or the thoughts and actions of the other characters, particularly the protagonist. Foil characters can be partner, antagonist or simply neutral observer. While a foil character can be included in a short story, to develop one adequately requires at least novella length or better yet, a whole series of stories. A foil character can also provide the opportunity to contribute comedic commentary on the story itself.

The most basic form of mythic dichotomy is the etiological Father Sky and Mother Earth tale. A Sumerian example was royal Gilgamesh opposed by primitive wildman Enkidu. The Hindu pantheon included Vishnu the Preserver in opposition to Shiva the Destroyer. In Norse legend, innocent Baldur was slain by devious Loki. Gabriel, the Semitic messenger of God, contested fallen Lucifer. In Greek folklore, rational virtuous Apollo was contrasted by free-spirited, chaotic Dionysus and vain Narcissus was partnered with reflective Echo. Many foil characters in mythology are demi-gods with one foot in each world. While capable of explicating the mysteries of Heaven or interacting with other gods, a demi-god is still mortal with concomitant attributes. So they should be considered as neither god nor human but an anomalous amalgamation of the two with special hybrid characteristics.

To apply accurate contrast, a foil character needs to be a near perfect reverse mirror image of the intended subject, highlighting its major traits in relief. The distinctions between the two characters can be starkly overt or subtly implied. This process need not be confined to just characters, polarized settings can also be employed for this purpose. Aesop's stories were the epitome of the moral fable and most of his tales involved mirror characters: fox and stork, hare and tortoise, grasshopper and ant. Since many science fiction stories are basically modernized mythic tales wrapped in technological speculation, it's no surprise that the use of foil characters would be one of the techniques adopted by sci-fi authors.

Examples of foil characters in more recent mainstream literature are legion. The many instances of elfin changelings adopted by human families certainly qualify. Other examples include the likes of Hamlet and Laertes; Don Quixote and Sancho Panza; Dr. Frankenstein and his Monster; Robinson Crusoe and Friday; Doctor Jekyll and Mr. Hyde; Sherlock Holmes and Dr. Watson; George Milton and Lenny Small in Of Mice and Men; Felix Unger and Oscar Madison; and Stan Laurel and Oliver Hardy. Even young naive Luke Skywalker and cynical Han Solo qualify.

When Star Trek first debuted in 1966, it concentrated on character development more than most TV series of that era. This commitment to characterization acutely focused on the supremacy of individual free will in relation to group social dynamics, a perfect platform for the employment of foil characters. A significant percentage of the plots involved one of the characters being isolated from the others, either physically or psychologically (isolation is the Sixth Step of the Mythic Hero Cycle). In keeping with the mythological underpinnings of science fiction, the literary principle of "twinning" was used time and again. The twin identity theme was accomplished by three basic methods: split or conjoined personalities; alien mental possession; or substitution of an altered replica of a character. Episodes based on alternate realities were also examples of this issue including those involving malfunctions of the holodeck hall-of-mirrors.

Just as importantly however, Gene Roddenberry was wise enough to add a classic example of the literary foil to the Star Trek cast in the form of Spock. His superior aptitude in knowledge and logic in conjunction with his emotional detachment, alien mental powers and inhuman strength made him an instant hit with science fiction fans. Spock was conceived by design as half-Vulcan, half-human to increase the complexity of this role. While Spock always strove to suppress his emotional compulsions, he did comprehend their genesis and effects. As the relationship between Spock, James Kirk and Leonard McCoy developed, it contrasted by mirror image not only the foibles of human ambition, sentimentality and passion but also Vulcan intellectual condescension. Thus Spock acted as a thematic foil.

However his main function was character foil. Where Jim Kirk is heroically handsome from a standardized formulaic perspective, Spock is strangely angular and alien. Kirk is the commander, Spock his subordinate. Kirk often relies on his ingrained intuition, Spock is devoted to logical deduction. Kirk demonstrates brash aggressiveness, Spock contemplative reflection. Kirk is the human yet Spock poses the most disturbing philosophical questions. Kirk's favorite pastime is rock climbing, Spock 3-D chess. Spock is supposedly unemotional yet develops a strong bond of friendship with two humans, Kirk and McCoy. McCoy is Kirk's conscience but Spock is his fortitude, relying on his counsel often. Spock also exhibits an astonishing capacity to deliver archly urbane one-liners for a Vulcan. This anachronistic facility, similar to the abilities of Basil Rathbone or Vincent Price, should not be possible for an unemotional character.

The Next Generation upped the ante by introducing the perfect paradigm foil in the form of an android. In effect, Data was the extension of Spock to maximum proportions. The next step up would have been a truly god-like being, an unacceptable complication that would have defeated the purpose of the stories. While being totally "inhuman" himself, Data reflected the thought processes not only of the human characters but all life forms, organic or otherwise. He possessed a vast database on psychology but comprehended none of it from an experiential standpoint. His greatest aspiration was to achieve this state of human consciousness and some of TNG's best episodes involved this subject. Data's comedic potential was also naturally high as he experimented with robotic adaptation to human social situations, reminiscent of the diastrous deadpan antics of Buster Keaton.

With the perfect mirror image possibilities already maxed out by Spock and Data, Deep Space 9 needed to refocus the foil role. Originally conceived as worthy opponents for Star Fleet, the Ferengi never managed to achieve this status. The show's writers instead used the basic features of the Ferengi mindset to create a warped funhouse mirror. By limiting the character of Quark to reflecting only human guile, deviousness and greed, the series abounded with opportunities to inject biting satiric humor into nearly any situation. Quark's brand of humor correlates with Groucho Marx's blatantly madcap avariciousness. Towards the end of the series however, Quark's character was allowed to expand, creating a less one-dimensional persona and proving that "people" could overcome their limitations with sufficient self-reflection. His classic nitwit brother Rom, a good analogue of Harpo Marx, likewise surpassed his original strictures.

By the time Voyager premiered, the role of literary foil had become permanently ensconced in the Star Trek oeuvre. As one of the few surviving members of his species, Neelix occupied the archetypical and emblematic "odd man out" position of orphan adopted into an alien society. The task bestowed upon this character was to reflect the power of human empathy if it were extended to perfection. No matter the situation or the creatures involved, Neelix always sought common purpose. This is in direct contrast to human society, past and present. So Neelix was used as a thematic foil rather than as character foil. He never evolved a true mirror relationship with any shipmate. So the compulsion to simply continue following Star Trek's successful formula caused this role to be misconceived. Not only did the role prove to be less stimulating than previous Star Trek examples but it reduced Neelix to a sad-sack type comedian along the lines of Emmett Kelly or Red Skelton's Freddie the Freeloader.

The character of Tes, Neelix's love, was another example of poor characterization in Voyager. Her mystic alien powers were used to highlight the pretense between human philosophical aspiration and the stark reality of their actions, similiar to Neelix's function but from a slightly different angle. She too was limited solely to the thematic foil purpose. Thus the role of Tes proved less attractive to viewers than other Star Trek characters and the role was purged in favor of the statuesque Seven of Nine. How's that for mirroring the truth of human reality!?

Nevertheless Neelix suggested the direction that the next Star Trek incarnation should take in Enterprise when it premiered in 2001. Doctor Phlox was the culmination of Gene Roddenberry's dictum of infinite diversity in infinite combination. Denobulans were idealistically compassionate and presaged what mankind would be like if they could not only accept all differences in lifestyle or philosophy but actually take delight in them as well. Phlox's benevolent devotion to his multi-partner family, his dedication to the medical treatment of any species and his affinity for his strange menagerie of weird pets were evidence of what might be achieved in this sphere. From a comedic perspective, Dr. Phlox could be compared with the self-effacing mockery of bourgeois pretense by Will Rogers. Of these five archetypical foil characters, Phlox could be considered as the most difficult to portray and John Billingsley's thoughtful performance was wonderful to watch.

The character of Worf was a special case. Klingons originated as fearsome opponents but became so conveniently productive in terms of expanding the Star Trek milieu that when The Next Generation premiered in 1987, the introduction of a Klingon into the regular cast was nearly inevitable. Even though Data already represented the role of foil, Worf proved to be equally useful in this function. Exiled from the Klingon Empire for being the scion of an infamous traitor and uneasily adopted into an alien society, Worf typified the dual nature of the foil character.

Worf was loyally devoted to Star Fleet, the Enterprise and Captain Picard in particular. These traits were in direct opposition to the usual Klingon attributes. The Klingon psychological pattern supposedly included a fierce devotion to duty but all too often, this was shown to be pure facade to conceal a predilection for prevarication and an inclination to ignore traditionally honorable ethics to achieve glory or for personal gain. Worf however was willing to sacrifice his own family's precious Klingon reputation to prevent a civil war. He was also dedicated to truthfulness, often bluntly stating what humans or even Klingons deemed too painful to speak aloud. Therefore Worf performed the purpose of foil for both humans and Klingons. In this position, he was capable of reflecting the idiosyncrasies of both from a dramatic and comedic perspective, much like the balancing act of a demi-god.

Guinan in The Next Generation can also be considered as a special example of thematic foil. Like Neelix, she too was an orphan of the mass extinction of her species surviving in an alien culture. Instead of mirroring conditions of present time, her oddly mystical temporal perception allowed her to reflect the thoughts of the other crewmembers from the perspective of past or future. Of these nine characters, all were at least half-alien with the exception of Data as the odd "odd man out."

Like so many other morality plays, Star Trek frequently preached out the side of its speech orfice. While espousing the "needs of the many," too often the show was more concerned with the "one man with a vision." In fact Space was not where "no men had gone before" . . . because they were accompanied by their alien mirror-twins.