There is a charming disconnect in the person of Somerset Frisby, a good-ole-boy country bumpkin and owner of a rural gas station and general store, who possesses both a remarkable intellectual interest and claimed expertise and experience over a vast swath of human knowledge and history. To anyone who will listen, Frisby expounds on his role in key historical event as well as on his expertise and accomplishments in such fields as meteorology, mathematics, and engineering. What is charming and admirable is that Frisby’s geographical and socioeconomic isolation are not barriers to his interests. His mind reaches effortlessly beyond the confines of Pitchville Flats. It is said that Immanuel Kant was never further than 100 miles from his birthplace in Königsberg, but his opinions and interests extended to the furthest reaches of the planet.
The similarity of Frisby and Kant ends here, as we notice that Frisby’s testimony doesn’t withstand the scrutiny of his peers. Like Frisby, his patrons and friends seek knowledge, and what they lack the experience and education Frisby claims to have, they make up for with their ability to assess the the plausibility of Frisby’s testimony.
How should we assess the testimony of others? When should we accept it and when should it be challenged? Surprisingly, this important question in epistemology was rarely taken up in the history of philosophy, though it is currently a major focus in the field. That may be because philosophers are often skeptical about whether knowledge can be shared, or transmitted from one person to another. Descartes begins his Meditations with the insight that he accepted many things as true as a child that he discovered (for himself) were in fact false. But it doesn’t follow from this that features of testimony are irrelevant to establishing what is known. Frisby’s customers reject his knowledge claim because they are internally inconsistent. The notice that he makes conflicting claims which can’t all be true. This is a starting point for considering when to find testimony credible and when to reject it. Assessing testimony has something to do with assessing the character and motives of the testifier.
The creatures who arrive from another planet encounter Frisby, but lack the most rudimentary tools for assessing his claims. On their planet, every claim made is true, and so they have no need to distinguish credible from non-credible testimony. Since Frisby claims to be the greatest human expert on just about everything, they count themselves lucky to have found him, and they plan to take him back to their planet.
Frisby faces a dilemma. How can he convince the aliens that his claims have been fabrications? There are two problems. First, the aliens claim to not understand what it is for a claim to be false. Second, even were they to possess the distinction between truth and falsehood, they would come face to face with The Paradox of the Liar: Frisby claims that everything he says is a lie. Is Frisby’s claim “Frisby’s claims are lies,” true or false? If it is true, then, as a claim of Frisby’s, it is a lie, and so it is false. If “Frisby’s claims are lies” is false, it is true.
If the aliens lack the distinction between truth and falsehood, then they will be spared the Liar Paradox. But they still will face the consequence of believing Frisby, and acting on that belief. But could aliens who arrive on our planet, capable of communicating with us and interacting with us, really lack the ability to understand the concept of falsehood? Notice that when Frisby begins to speculate about how he will be treated on their planet, the aliens try to put him at ease, assuring him that his speculation is incorrect, that is that his belief about how he will be treated is false. It seems that the aliens must have the concept of falsehood after all.