|To be fair, I'd react the same way to being given something|
by someone whose name is literally "Shill." I mean, come on.
In ponies, Josh Harber returns for his third outing (both this season and overall), "Leap of Faith." Despite the title, this episode is largely about the importance of skepticism and extending the principle of honesty not just to interactions with others, but to oneself.
Applejack is struggling with two distinct problems in this episode. The first is what it means to be honest. Naively, we might say that being honest is a matter of saying and believing true things to the best of one's ability, but that simply passes the buck on to the next question, of what it actually means to be truthful. Which is, in turn, a vast philosophical question way outside the scope of a twelve hundred-word essay about an episode of My Little Pony, so we will simply outline a few ways in which it is a problem and then move to how Applejack deals with it.
Consider these two statements: "Value is in the eye of the beholder; one person's trash may be another's treasure," and "Platinum is worth about $1,200 per troy ounce." Both are true (as of this writing in the case of the latter), yet they appear to contradict one another. However, that is because they are being artificially placed next to each other; generally these statements would never appear together because they apply in different contexts. A person who states a specific dollar value for an ounce of platinum is almost certainly speaking in terms of the commodities market, while a person making the former statement is most likely speaking philosophically, probably in the realms of aesthetics, ethics, or politics. To try to argue against either statement by proposing the other is likely to result only in confusion, since each statement is inapplicable to the other's context.
But there we are dealing with fuzzy, human-made concepts like value. Surely the hard sciences can provide some hard truths? Not so much, unfortunately. Consider gravity. For an engineering project, say the construction of a bridge, gravity is a constant acceleration of 9.8 meters per second per second. But if you're trying to put a spacecraft into orbit, then the acceleration due to gravity varies based on one's distance from the Earth according to Newton's laws--and for astronomers taking advantage of gravitational lensing to study distant galaxies, it instead functions according to Einstein's theory of general relativity. Now, one can argue that these are just successive refinements--applying the theory of general relativity does give one a figure for the surface gravity of the Earth very near to 9.8 meters per second per second. But that's not what engineers actually do; they just use the 9.8 figure, because it's more useful to them--it is a better model, so we could argue that it's true in that context.
Or not. We could equally well argue that the statement about value being in the eye of the beholder is clearly false, and the value of platinum is determined by the market. Or we could argue that the market is trying to impose consensus on something that is inherently a matter of individual judgment. Or...
The point is, the question is difficult, so being honest is difficult. And that's exactly the situation Applejack finds herself in: it is true that Granny Smith is more athletic and healthier as a result of drinking the tonic. And it's also true that Flim and Flam are selling a "tonic" that contains neither medicine nor magic, and employing the unscrupulous and duplicitous tactic of paying a shill to give false testimonials on their behalf to up their sales. There is, in other words, a case to be made that the tonic helps Granny Smith, and a case to be made that Flim and Flam are liars.
It's debatable whether Applejack has a responsibility to tell Granny that the tonic isn't helping her, when it is--it's just that the process by which it's helping her, namely the combination of the placebo effect and a confidence boost, could be easily replicated in ways that don't require paying money to con artists. However, it is definitely dishonest of her to help Flim and Flam continue to lie about their tonic's healing powers--and it is a lie, as demonstrated by the number of ponies who appear in their audience multiple times.
This puts Applejack in a rare situation for her, which is quite welcome in terms of making her character more interesting: an actual dilemma. She is torn between not wanting to hurt Granny Smith, and her drive to be honest and not support liars, which leaves her no choice but to deceive herself into believing that no harm will come of Flim and Flam's lies. This is where the episode becomes, in many ways, a response to Season One's "Feeling Pinkie Keen." There, Twilight refused to believe in a phenomenon that was actually (unlike real-world claims of psychic powers) demonstrable and measurable, and her closed-mindedness resulted in her coming to harm. Here, Granny Smith's belief is instead what nearly brings her to serious harm, because she chose to believe (the titular "leap of faith") in a falsehood.
Applejack's mistake was in treating Flim and Flam's "miracle cure" like an article of faith, which is to say a statement with no material consequences. What I mean by this is that the material universe is actually the same place whether Granny Smith has confidence in herself or not--her capacity to swim was there all along, and she actualized it by believing she could do it. However, there is a big difference between a universe where Flim and Flam's tonic can actually reverse the effects of aging, illness, and injury and one where it cannot--in the former, leaping facefirst from a great height into a pie tin of water might not end in disaster, while in the latter it definitely will. And Applejack knows for a fact that she lives in the latter universe, because she's seen Flim and Flam making their tonic and met Silver Shill.
Ultimately, of course, Applejack decides to be honest, which here appears to mean acknowledging and respecting the universe in which one actually lives, as reasonable a definition as any, and in the process she teaches Silver Shill a lesson and receives the penultimate key. This is the least spiritual episode in the key arc, but that makes sense for Gevurah, the sephirah of Strength; it is the capacity for judgment and the imposition of limitation, the separating out of that which is false, and so its episode is devoted to skepticism and tracing the limits of the spiritual, which is that it must not be dishonest. It is fine to believe, for instance, in a drink that boosts confidence, but only so long as one is aware that confidence comes from the belief, not the drink. A drink that grants superpowers, by contrast, is right out. Which is to say, the role of the spiritual is here established to be in shaping our perceptions and attitudes, but only material action can shape the material. It is not enough to think, to feel, to wish; we must also do, and our doing must be shaped by honest appraisal of the material effects of our actions.
Next week: Which is not to say that our perceptions don't matter or are entirely of our own choice, either...