In the past, knowledge was commonly described as justified true belief (referred to as JTB). This means that a subject knows a proposition if and only if (iff) the proposition is true, the subject believes the proposition and the subject is justified in believing the proposition. This is the traditional view of what knowledge is. However, this has been seen as problematic by many philosophers for several reasons and so I will attempt to determine if this is true and just how well this traditional view of knowledge functions. In this essay, I will first describe the three conditions necessary for the traditional view of knowledge, then I will describe Gettier Cases. After that, I will explain the responses to Gettier Cases and qualia, before moving onto Agrippa’s Trilemma and then concluding.
To answer the question of whether knowledge is justified true belief, we must first understand what these three qualifiers mean. Firstly, justification is evidence for your belief. This comes from either first-person observation or testimony from others that we think is reliable, for example, things told to us by teachers or friends who seem to know what they’re talking about, journal articles or the news. You must be justified in your belief because having only belief and truth alone would not result in knowledge, instead, this would be a mere accident. The proposition (in this case, the underlying meaning of your belief) must be true because knowledge has a prerequisite of truth — you cannot have false knowledge, only false beliefs. Finally, belief is a propositional attitude of truth – you believe that the proposition corresponds to reality. You must have belief that the proposition is true, or you would not know the proposition, even if it was true.
Each condition must be met for a person to have knowledge, under this definition. However, these three qualifiers alone are not sufficient to form knowledge, which will now be further discussed.
Edmund Gettier discussed this in [cite]. Until he put forward his point, most philosophers agreed on the JTB theory of knowledge, but Gettier realised that you can have situations wherein you can have JTB but no knowledge. To illustrate this, he used the example of a job application. Smith and Jones have both applied for a job. Smith has been told by the president of the company that Jones will get the job, and somehow, Smith counts the coins in Jones’ pocket, finding ten. Smith extrapolates that the man who gets the job has ten coins in his pocket. Smith is justified in believing that this is true. However, Smith is the one who actually gets the job. Unknown to him, he also has ten coins in his pocket. Smith’s proposition that the man who gets the job will have ten coins in his pocket is true, even though the proposition that was inferred from (that Jones is the man who will get the job and he has ten coins in his pocket) was false. It was, therefore, an accident that his proposition that the man who gets the job will have ten coins in his pocket is true — he has justified true belief for it, but no knowledge of it. [cite — case 1]. There have been many other examples which result in the same issue since Gettier first realised this, and these are now known as Gettier cases. Therefore, even if you have a justified belief which happens to be true, this does not mean you have knowledge.
One way that the problem of Gettier cases can be resolved is through the no false lemmas analysis. Micheal Clark claims that a better definition of knowledge would be that S knows P iff P is true, S believes that P, S is justified in believing that P and it is on true grounds that S believes P. [cite] However, this may rule out too much, as if you have a lot of justifications for a belief and one of these justifications turn out to be faulty, you would never be able to have knowledge, even if the rest of your justifications were trustworthy, as the true grounds principle would be breached.
From this, however, came the undefeatability analysis, which argued that there are two kinds of knowledge: basic and non-basic. Lehrer and Paxson argue that basic knowledge is true belief with complete justification that is independent of any justifying statement, for example, sensations and experiences we feel first hand. Contrastingly, non-basic knowledge is the kind which causes Gettier cases as it requires supporting evidence. Lehrer and Paxson outlined why it is that Gettier cases occur — because of hidden facts which ruin the justification, known as defeaters. This means that if the subject knew the truth behind their justification, they would no longer be justified in believing the proposition. Non-basic knowledge, then, needs undefeated justified true belief. However, you can have knowledge in the presence of a defeater, as long as there is a defeater which cancels out the original defeater. For example, a hidden twist may not have been a fact, but a product of something else, like pathological lying. Defeaters can, therefore, coexist with knowledge as long as they are also defeated. Only undefeated defeaters can stop knowledge. On these grounds, I believe it most sensible to say that rather than knowledge being simple justified true belief, knowledge is undefeated justified true belief. However, there are still issues with this. For example, what actually is justification?
One argument that says knowledge cannot be JTB, even if it is undefeated, is about experience and sensation (known as qualia). Frank Jackson proposed a thought experiment about a woman named Mary, a woman who has spent her entire life seeing only in black and white. While locked in the room, she became a neuro-physicist specialising in the science of colour. She learns everything there is to know about colour, but she has never seen it for herself. If she finally walks out of the room and finally saw colour for the first time, has she learned something new? [cite] Jackson therefore claimed that knowing facts about something is not the same as experiencing something. If everything could be explained in terms of physicality, Mary would not have learned anything new. Therefore, knowledge is not just a thing that we are justified in believing and is also true — very basic things, like what the colour red looks like, cannot be described in this way. However, some say that Jackson’s experiment begs the question, which is a fallacy in which the premises assume the conclusion they’re supposed to be proving, as Jackson assumes that Mary does learn something new when she leaves the room. This may not be propositional knowledge, like the knowledge discussed by many philosophers, but this is important in itself in my opinion
It is also questionable as to whether anything can actually be justified. Micheal Williams writes about this when discussing Agrippa’s Trilemma. He argues that having knowledge of anything is impossible due to the reasoning found in theoretical/philosophical scepticism. Agrippa’s Trilemma is found in the Five Modes of Agrippa.
The Five Modes are Discrepancy, Relativity, Infinity, Assumption, and Circularity. The Mode of Discrepancy says that people can disagree about anything, and the Mode of Relativity says that anything a person claims to know is relative to themselves, in their own culture with their own beliefs. However, some views are simply incorrect, and some are much better supported than others.
Once a claim has been made, a person may be asked to explain why this is so — others are entitled to know why you claim it is the truth. Every claim falls due to one of the final three Modes. Firstly, the Mode of Infinity, wherein you try to think of a new answer to every question as to why you believe a proposition. This leads to infinite regress (ad infinitum), which means you will never come to a point where you have justified your belief. Secondly, the Mode of Assumption — eventually, your answer will become dogmatic termination (as in, it is the way it is because I said so). Finally, the Mode of Circularity, in which you will answer the question with a reason you used earlier in the chain.
One criticism of this is that it is not always dogmatic to break a chain of reasoning, for example, in mathematics. Also, if you are trying to explain why you believe something to someone else and can eventually reach a common ground, you will not need to continue explaining to them why you believe the proposition. Additionally, some philosophers argue for coherence theory — if a belief can be integrated into a coherent belief system, it is justified due to its ease working in tandem. However, this does raise the issue similar to that of the argument for belief from dreaming: if everything is a dream, then of course what you know will be coherent within it, but this does not guarantee that your belief is true.
In conclusion, I think it is unreasonable to argue that justified true belief can be equated to knowledge and that the no-defeater analysis is the best fit for knowledge that we currently have, although it does have problems of its own. For now, knowledge remains ambiguous in definition, so we will have to make do with our intuitions and reasoning together.