Misleading Defeaters
Once the assumption that justification is a necessary component of knowledge is discarded, the Gettier game can no longer be played. In its place, I have recommended a different game: when a subject has a true belief but seems not to have knowledge, look for some key aspect of the situation about which the subject lacks true beliefs.
Defeasibility theorists make a strikingly similar recommendation. When confronted with cases in which a subject intuitively lacks knowledge despite having a justified true belief, they too recommend looking for a truth about the situation that the subject lacks, but because they are committed to the Gettier game, they link the subject’s ignorance of this truth with the justification requirement. The subject lacks knowledge, they say, because the missing truth, if believed, would defeat the subject’s justification for the target belief. But once the link between justification and knowledge is severed, as it should be in any event,1 a simpler explanation is possible. The subject lacks knowledge because she isn’t aware of an important truth.
Consider a story discussed by Peter Klein, a leading proponent of the defeasibility theory.2 Loretta has been working on her federal taxes. She has followed the procedures on the forms carefully, done the calculations meticulously, and as a result correctly believes she owes $500. She is nonetheless worried that she may have made an error. So, she has asked her accountant to verify her return. The accountant has done so and has found no errors, but in writing to Loretta he inadvertently leaves out the word “no,” so that his letter reads, “Your return contains errors.” Loretta has received the letter but not yet opened it. It lies unread on Loretta’s desk.
Loretta has a justified true belief that she owes $500, and despite the fact that there is a truth that would defeat the justification for her belief (the truth that the letter from her accountant contains the sentence “Your return contains errors”), we are inclined, says Klein, to grant she has knowledge. But if so, defeasibility theorists have a problem, as Klein himself recognizes. The problem can be solved, he argues, by introducing a distinction between genuine and misleading defeaters. Although reading the letter from her accountant would defeat the justification for her belief, Loretta nonetheless knows that she owes $500, because the defeating truth here is misleading.
Of course, this merely pushes the problem back a level, the question now being, what distinguishes misleading from genuine defeaters? Klein’s answer, some details aside, is that a defeater is misleading if it justifies a falsehood in the process of defeating the justification for the target belief. In the case here, the falsehood is that the accountant had in fact discovered an error in going over Loretta’s return.
By contrast, if knowledge is viewed as adequate information, the critical question to ask about this story is, how important is the gap in Loretta’s information? As with other stories in the post-Gettier literature, we the audience are given information that the subject Loretta lacks, in this case that the unopened accountant’s letter states that there are errors in her return. Is this gap significant? Well, if she had read the letter, she would not have been as convinced as she is now that she owes $500. So, the letter is not beside the point, but had she read the letter, what would have happened next? One likely scenario is that she would have called her accountant and asked what the errors were, at which point she would have discovered that his letter contains a typo. In other words, on one natural expansion of the story, indeed, the very expansion that lies behind the intuition that Loretta knows, had she read the letter, this would have prompted her to acquire additional information that would have quickly countered the misleading sentence in the letter.
On the other hand, there are alternative ways of expanding any story, and with the story here, some of the expansions would raise the significance of the gap in Loretta’s information. Suppose her accountant is now on vacation and thus, had she opened the letter and called her accountant’s office, she would have spoken to the office administrator, who, let us further stipulate, would have told her that the accountant is always extremely careful in writing such letters. If pressed by Loretta for details, the administrator would have called the accountant on vacation, who having just finished working on scores of returns would not have remembered the details of Loretta’s, but he would have instructed his administrator to reassure Loretta that he is always extremely fastidious in preparing his responses and thus whatever he wrote in his note is almost certainly accurate.
As the story is expanded in this direction, some listeners may be pulled away from the intuition that Loretta knows she owes $500. But if so, defeasibility theorists will need to explain why. What is the genuine defeater? Is there some additional factor in the revised story that turns the relevant truth here (the truth that the letter from the accountant contains the sentence “Your return contains errors”) from a misleading defeater into a genuine defeater, or is there perhaps another, more complicated truth that defeats her justification without justifying a falsehood?
Defeasibility theorists may be able to patch together answers to such questions,3 or they may choose simply to dig in their heels and insist that in both expansions of the story, it is clear that Loretta has knowledge. Be this as it may, there is a simpler and more direct way to treat these cases. Namely, the first expansion of the story makes Loretta’s missing information seem relatively trivial, whereas the second makes it appear more serious. In particular, the first expansion is such that the misleading sentence in the unopened letter, had Loretta read it, would have been easily and quickly corrected, whereas in the second expansion this is pointedly not the case. On the contrary, reading the letter would have resulted in her obtaining additional confirmation that the letter as written is correct. The gap in her information thus begins to look more significant, and as a result there may be a corresponding pull away from knowledge.