AGAINST GETTIER Rodrigo Reis Lastra Cid Universidade Federal do Rio de Janeiro In "Is Justified True Belief Knowledge?", Edmund Gettier attacked the thesis that S knows that P iff P is true, S believes that P, and S is justified in believing that P, to sustain that someone can have a true justified belief without knowing that belief. He made that by creating two counter-examples to that thesis. In this article, I will try to show that Gettier's arguments are based in a weak account of justification, and that such a weak view cannot talk about someone knowing something. I begin by presenting his counter-examples, and then I show they do not work. Gettier's First Counter-Example Smith and Jones applied for a job, and Smith has strong evidence for this conjunctive proposition: (d) "Jones is the man who will get the job and Jones has ten coins in his pocket". This entails that (e) "the man who will get the job has ten coins in his pocket". If there is strong evidence for (d) – if (d) is justified – there is strong evidence for (e), because (e) is deduced from (d) and (d) is based in strong evidence. Gettier also said that such strong evidence might be something like the president of the company had assured Smith about Jones getting the job and like the fact of Smith had counted the coins in Jones's pocket ten minutes ago. The main point is now: if in fact Smith, and not Jones, will get the job, and he also has ten coins in his pocket, so (e) is true, Smith believes that (e), and Smith is justified in believing that (e), although he does not know (e), because the base from where he inferred (e) is false. Such a base, (d), is false because Jones is not the man who will get the job. The conclusion Gettier arose from that was that from the facts that (e) is true, Smith believes that (e), and Smith is justified in believing that (e), we cannot conclude that Smith knows (e). Gettier's Second Counter-Example Smith has strong evidence for the proposition (f) "John owns a Ford". Such strong evidence might be something like Jones had gave Smith a ride in a Ford today and the fact that Jones always in the past had a Ford. (f) entails the proposition (h) "Either Jones owns a Ford, or Brown is in Barcelona", even without Smith knowing where Brown is located; what, in the example, he does not know. Again, if there is strong evidence for (f) – if (f) is justified – there is strong evidence for (h), because (h) is deduced from (f) and (f) is based in strong evidence. Then, Gettier asks us to imagine that Brown is really in Barcelona, and that Jones had sold his car, and just had rented that Ford. In this case, for Gettier: (h) is true, Smith believes that (h), Smith is justified in believing that (h), and even so Smith does not know (h), because the first simple proposition from (f) is false, and because Smith didn't know the second one. Strong and weak justifications: knowing and believing I think Gettier's counter-examples would fit only if we have a weak notion of justification. A weak notion of justification is that someone is justified that P if he/she has good reasons to believe that P, but those reasons do not make not-P impossible; whose reasons I will call "weak evidence". A strong notion of justification is that someone has a justification for P, if such justification makes not-P impossible. I will call "strong evidence" the reasons given in a strong justification. We could say that, in the first example, Smith does not have strong evidence to believe that Jones will get the job; after all, the president of the company saying so does not make impossible the truth of "it is not the case that Jones will get the job". A strong evidence would be something like the signed papers contracting Jones: if the papers are signed, and if the rule is that just one person can get the job, it means Jones got the job. But if we say Jones will get the job only because the president said so, it does not make impossible the negation of "Jones will get the job", although it is a good reason to think that he will. So, what the president told Smith is a good reason to Smith to think that Jones will get the job, but it is not a strong justification of it. Thus, if Smith has not a strong justification for both sentences in (d), and if (e) is deduced from (d), then Smith does not have a strong justification for (e). The second counter-example follows the same path. Smith is not strongly justified in believing that (f) "Jones has a Ford"; he would be if he had seen the papers of the ownership from the car in the name of Jones. The reasons given by Smith to justify that (f) do not make impossible not-(f); what make them weak justifications. My point is that a weak notion of justification cannot be given as a justification to know something. If I know something, I cannot be wrong in what I know. If I just believe something, I can be wrong, although I must have some good reasons to believe in what I believe. So, if I want to justify the assertion that I know something, and not merely believe it, I have to justify it with reasons to know it, and not with reasons to merely believe it. The only justification that would produce a reason to know something would be a justification that makes impossible the negation of my assertion, because if it is impossible that not-P, so I cannot be wrong when I say that P; so, if I know a reason that makes not-P impossible, I know that P. Gettier, in his examples, always takes weak evidences as reasons to know something. And it is for this that he always finds that a true justified belief is not sufficient for knowledge. He is right iff we use a weak concept of justification. If we use a strong one, Smith would not be justified in knowing that Jones will get the job and, hence, he won't be justified in knowing that the man who will get the job has ten coins in his pocket. Thus, if it is true that the man who will get the job has ten coins in his pocket and that Smith believes it, if he has not a strong justification of it, it would not be an absurd to say that Smith does not know it and just believe it. In another way, if Smith is strongly justified in believing that the man who will get the job is Jones – for example, he had seen the contracting papers signed by the president in Jones's mail – and that Jones has ten coins in his pocket, so he is strongly justified in believing that the man who will get the job has ten coins in his pocket; hence he knows that the man who will get the job has ten coins in his pocket, and he cannot be wrong. Thus, what Gettier really shows us is that if we say that we know something only based in weak justifications, it will lead us to the problem explored in his examples. What I tried to show was that if we use strong justifications, Gettier's problems will not arise, and we can continuing thinking that S knows that P when P is true, S believes that P, and S is [strongly] justified in believing so.