The link between the Venus Pill (crystal) and the (Di)Lithium crystals is a brilliant insight on Dennis' part. The Enterprise, and by extension the Federation, like Mudd's women, are addicted to a substance. It is easy to see that both substances yield power, material and ideological. The Venus Pill transforms the human body into a thing of beauty and that "beauty" works on/in the world or galaxy. The (Di) Lithium crystals do the same thing--they empower and make beautiful the Enterprise, which, in turn, carries the ideological message of the Federation. (The opening scene suggests this as the Enterprise is "interdicting" a wayward craft.) The initial analogy "the Venus Pill is to Mudd's women as (Di)Lithium cystals are to the Enterprise" begins to breakdown around the question of authenticity. That is, the analogy turns into a dialectical comparison, with Venus Pill + Mudd's women = Fraud; while (Di)Lithium crystals + Enterprise = Authentic or Ideal Values. It is later, of course, when the Venus Pills are shown to be a placebo, that the ontologically Real is revealed.
Before we get to this point, as few historical and sociological questions emerge. Is the Venus Pill allegorically connected to the birth control pill? In 1968, it is difficult to imagine any "Pill" that women take in a television episode wouldn't somehow reference "The Pill." Is Roddenberry making a conservative, reactionary argument? The "Venus Pill" gives you "fake" women--not wives and mothers, but "cheats and frauds," e.g. women who do not reproduce or cook as Eve suggests. The "Pill" works to cheat "Edenic" domesticity and Eve says as much; "Is this what you want?" she asks after having transformed into her sultry ideal. While Star Trek is often "progressive," this episode seems starkly conservative if the analogy or dialectical comparison holds. The end of the episode seems to bear this out when Eve, believing in herself, and the miner decide to spend a wholesome day together "talking"--presumably before the sub-space wedding ceremony.
Like so many Star Trek episodes, we have multiple layers of text. "Mudd's Women" shows the imperial, economical brutal foundation of the Federation--miners die to supply the crystals. We have the sociological--"fake, pilled" women threaten the moral fabric of civilization. We also have an issue of the "real" as it ties together these layers. It is the final scene on the wind-swept planet that caught my attention.
When Mudd gives Eve the "fake" pill, she transforms into her "beautiful" self--faking, the fake yields the truth it seems. This negation of the negation works well with the recent Deleuzean/Badiouian/Zizekian discussion of the "real." Here is the very abrreviated sketch: If we live in equivocity, then the ideal rests "behind" the sensible. The Venus Pill shows that behind the outward appearance there is a really, real ideal form. This, in the episode, becomes a conflict between the "authentic" and the "fraudulent." The Venus Pill gives us the Platonic ideal, but the sensible real persists. The problem with Mudd's Women, however, is that it is the opposite--the ideal is the fake, and the sensible material is the real. This is a reverse equivocal or dualist Platonism, a.k.a Aristotlianism. The issue doesn't end there. The "fake" real ideal undergoes a negation in which the "fake" real, the beautiful Eve, becomes the authentic real--a double negation. The negation of the negation within equivocity, then, yields a univocity, which gets expressed in Kirk and Mudd's "there is only one woman or man." The final comment appears in the context of Eve believing in herself and thus manifesting her true self; however, what is really being said at the metaphysical level is that there is no equivocity--the appearance is the real because, in Zizekian terms, the appearance is the expression of the absence of the ideal/sensible divide. In other words, "there is only one woman or man" means that there is one "parallax" real and that real exists because of the absence of the ideal, Platonic real (e.g. the Venus Pill-Eve) and the sensible ugly Eve. So there is only one woman and one man is, " there is no dualism in which one finds a perfect-ideal and an imperfect sensible--there is only one, univocal material real that is the negation of the negation of either pole. This allows Zizek to say that the appearance is the real, which is exactly what Kirk and Mudd say.
All of this, to me, makes perfect sense insofar as it is Harcourt Fenton Mudd who IS the central figure in the episode. Eve, the Pill, the Dilithium crystals are all a vast surface upon which "Mudd" the con-man is examined. Confidence games are metaphysical games--they depend on a dualism involving authenticity and fraudulence. What this episode shows is that the equivocity one associates with dualism is false. Mudd is not a con man because there is some abstract true, even the computer/lie detector is tricked by Mudd, or some absolute falsehood--he is a con man because, in a sense, both are negated and it is the irony or Zizekian dialectic of the two that makes him, in the end an honest man because he looks like a scoundrel.