What is Knowledge?
Introduction
We all know a variety of things. For example, I know that the Earth revolves around the sun, that whales are mammals, and that the moon is not made of cheese. There are, of course, a variety of things that I don’t know. For example, I don’t know whether there is an even or odd number of sheep in New Zealand, I don’t know what (if anything) happened before the Big Bang, and I don’t know what the first word ever spoken by a human was. Of course, I could assert that I know that there are an even number of sheep in New Zealand or that the first word ever spoken by a human was “curtain.” But if I said that I knew these statements then I would be mistaken. There are presumably reasons as to why it is appropriate for me to claim to know some statements but not others. Discovering what these reasons are is the main goal of epistemology.
Epistemology is the philosophical study of knowledge, and—like ethics—epistemology is a normative study (meaning it is about what someone ought or should do). Epistemology is specifically concerned with what we should do to attain knowledge. To figure that out, we first need to answer other questions related to knowledge. Most importantly, we will need to figure out what knowledge is, which we will cover in this chapter. By the end of this chapter, you should be able to:
- identify the differences between knowledge-that and knowledge-how
- identify obvious examples of justified true belief and non-justified true belief
- explain why proponents of the JTB account think that justification, truth, and belief are necessary for knowledge
- explain why the Gettier problem challenges the JTB account of knowledge
- identify and create your own Gettier cases.
‘Knowledge-that’ and ‘knowledge-how’
Before I continue with the chapter, it is first important to specify the type of knowledge we will discuss. To do that, compare the sentence “I know how to ride a bicycle” with “I know that bicycles have two wheels.” The first sentence demonstrates an instance of knowledge-how, or the ability to do a specific task. The second sentence demonstrates an instance of knowledge-that, or knowledge that a specific statement is true. Knowledge-how is learned in a completely different manner than knowledge-that. If I want to learn how to ride a bicycle, then you need to hop on a bicycle and practice. But if you want to know how many wheels a bicycle has, then you can just see a bicycle and find out. These are both legitimate types of knowledge, but epistemologists are generally concerned with knowledge-that.
Why are epistemologists primarily concerned with knowledge-that rather than knowledge-how? The reason is that epistemologists are fundamentally concerned with discovering what is true. Knowledge-that is different from knowledge-how since a knowledge-that statement is either true or false. Meanwhile, knowledge-how is simply concerned with what people can do (or the mere ability to do something). Of course, you could say that the statement “I know how to ride a bicycle” is either true of false, but when you express it in this way, then you are actually just making a knowledge-that claim (you can think of this as “I know that it is the case that I can ride a bicycle”). It is important to note that there is a difference between the actual ability to ride a bicycle (knowledge-how) and the statement that one can ride a bicycle (knowledge-that).
Knowledge as Justified, True Belief
To figure out how to attain knowledge, we first need to ask, what is knowledge? To answer this question, I think it is best to run through some scenarios that will help us identify what conditions need to be met to attain knowledge.
Consider the following scenarios:
Tom knows that horses have four legs. Thus, when asked how many legs horses have, Tom replied, “four.”
Samantha knew that the semi-truck was on a path to hit her car. She thus swerved out of the way.
What similarities exist between these two cases of knowledge? One similarity is that both Tom and Samantha consciously think that the statement (which they know) is true. In other words, both Tom and Samantha believe the relevant statement. This may seem very basic, but one must have a belief to attain knowledge. Thus, our first condition for knowledge is belief. Let’s move on.
Consider the following scenarios:
George knows that his father is home. His father is home.
Carla knows that her cat, Mortimer, is sleeping. But Mortimer is actually awake.
Let us ask ourselves, do these statements sound like proper instances of someone attaining knowledge? It intuitively seems reasonable to say that George knows that his father is home, but it does not seem reasonable to say that Carla knows that her cat is sleeping. This leads us to the question, what is the difference between these two scenarios? One obvious difference is that George’s father is actually home while Mortimer is not actually sleeping. Thus, it seems that George’s belief is true while Carla’s belief is not. Thus, truth seems to be our second condition. Let’s carry on.
Consider these scenarios:
Devin saw a sci-fi movie about a species of aliens that live on Venus. Because Devin really liked this movie, he now believes that there are aliens on Venus. Surprisingly, Devin is right; there are aliens on Venus.
McGwire is a scientist who studies the atmospheres of other planets. While studying a distant exoplanet, he realizes that there are chemicals in the atmosphere that could only be produced by living creatures. This discovery prompts him to believe that there are aliens on this planet. He is right.
Intuitively, it seems strange to say that Devin attained knowledge, but it seems perfectly fine to say that McGwire attained knowledge. What is the difference between these two cases? One obvious difference is that Devin did not have good reason to believe that there are aliens on Venus, but McGwire had a good reason to believe that there is life on that exoplanet. Epistemologists refer to this reason as justification which will be our final condition for knowledge (for now).
Putting all our findings together, we notice that knowledge is a belief that is justified by the believer and true. This account of knowledge is referred to as the Justified, True, Belief Account (or JTB for short). The origin of this account of knowledge is accredited to Plato in his Theaetetus.[1] Up until recently, nearly every epistemologist since the time of Plato agreed with the JTB account of knowledge.
[1] See Plato, McDowell (1973).
What is truth, belief and justification?
So far, we have discovered that knowledge is attained when somebody has a belief that is justified and true. However, it is important for us to briefly consider what these conditions mean exactly. Unfortunately for us, the exact definition of ‘truth’, ‘justification’, and ‘belief’ are contentious topics in philosophy, and we do not have the time here to cover the vast amount of literature on these topics. Instead, I will offer some brief thoughts about what these words may reasonably mean.
Truth
The most historically significant theory of truth is called the Correspondence Theory, and it is usually attributed to Plato and Aristotle (Marian, 2002). In short, a proposition (essentially a statement that can be true or false) is true only if it corresponds to the real world. So, if I believe that Maisie the cat has a tail then that belief can only be considered true if the picture that I have in my mind of Maisie matches up with Maisie in real life. There is much more to be said about the correspondence theory; however, I will leave the discussion of truth here for now.
Belief
Although there is still interesting philosophy to be done, it is a bit easier to define ‘belief’ than it is to define ‘truth’ or ‘justification’. A person has a belief when she holds the opinion that something is true. Furthermore, although this may seem obvious, it is important to note that there needs to be a believer for there to be a belief. Additionally, a belief must be a proposition, meaning that a belief needs to either be true or false. So, somebody could believe that the Earth is flat, but they could not believe ‘wow!’, since ‘wow!’ is not the type of statement that could be true or false.
Justification
If we were making a recipe for knowledge, then justification would be the last thing needed to turn an instance of someone having a mere true belief into an instance of her attaining knowledge. It is much harder to define justification than it is to define truth or belief so identifying the correct account of justification is of critical importance to the epistemologist. I do not have the room here to go in-depth into the topic, but I do want to give some initial thoughts. It is intuitive to say that having a justified belief corresponds to having some sort of evidence for that belief. So, if Carla looks at Mortimer and notices that he is lying down on the cat post with his eyes closed, then those observations give her reason (or evidence) to believe that Mortimer is asleep. If Carla simply believes that Mortimer is asleep but there is no evidence to support her belief, then she is presumably holding an unjustified belief.
This automatically leads us to ask, what forms of evidence can lead to justification? Presumably people are justified in believing things based upon what they sense, after all, it seems reasonable for me to think that Mortimer is in the room if I see him in the room. It is also reasonable to say that deductive reasoning can lead me to a justified belief. For example, I am justified in believing a proposition about mathematics if I see a mathematical proof that shows that the given proposition is true. Furthermore, it is intuitive that testimony can lead me to a justified belief. If the clerk at the grocery store tells me that my groceries will cost $43.95, then I have good reason to trust him and believe that my groceries will cost $43.95. Of course there are many more forms of justification, but this should cover everything we will need to know for the rest of this chapter.
Is justified, true belief sufficient for knowledge?
The JTB account of knowledge was largely uncontroversial up until the 20th century. For about two-thousand years the primary concern of epistemologists was spelling out exactly what it meant to have a justified true belief; however, the philosopher Edmund Gettier released a now famous essay titled, “Is knowledge justified true belief?” in 1963 which forced epistemologists to reconsider whether knowledge truly was best characterized as justified true belief.
Gettier’s essay covers a few specific counterexamples in which a person possesses a justified true belief but intuitively does not possess knowledge. His examples are more complicated than they need to be, so I wrote a few equivalent examples which get at the same point. All Gettier cases involve a situation in which a person has justification for a belief, which turns out to be true, but the belief is not true for the reason that the person believes it. That’s a bit difficult to follow, so consider the following example:
The Phony Professor: Elek is taking Professor Smith’s biology class. In one of his lectures, Professor Smith states that the closest living relative to a tyrannosaurus rex is a chicken. Elek thus comes to believe that the closest living relative to a tyrannosaurus rex is a chicken since Professor Smith said so and he is (presumably) a credible source of information. Contrary to Elek’s belief, Professor Smith is a phony who faked his biology degree and has just been making up facts (including this one) to tell his ignorant students. However, it coincidentally turns out that the closest living relative to a tyrannosaurus rex is a chicken.
Does Elek know that the closest living relative to a tyrannosaurus rex is a chicken? He intuitively doesn’t know that. However, Elek has a justified true belief since he has good reason to believe that fact and is correct. But it seems like Elek hasn’t attained knowledge despite his justified true belief. Elek was simply lucky, so he presumably hasn’t achieved knowledge. Additionally, consider this next example:
The Kids in the Trench Coat: Magnus works in the ticket booth at a movie theater. The movie theater had begun playing a new slasher film, “Death Strangler 9,” which prompted plenty of kids to attempt to sneak into the movie. While Magnus is working at the booth, a customer walks up to the booth and asks for a ticket. Magnus notices the customer is wearing a large trench coat, hat, and fake beard. Furthermore, the customer seemed too tall and sounded more like a child than an adult. Magnus thus inferred that the customer is indeed two children in a trench coat disguising themselves as adults to sneak into “Death Strangler 9.” Magnus does not want to cause any conflict, so he sells the customer a ticket and then comes to believe that a few children had snuck into that showing of “Death Strangler 9.” It turns out that the customer who Magnus served was an adult (just a tall adult with a high-pitched voice who likes to wear fake beards); however, there coincidentally were a few children that successfully snuck into that showing so Magnus was luckily correct.
It seems like Magnus is justified in believing that a few kids snuck into the showtime (since he had evidence that the customer was just two kids in a trench coat), and Magnus holds a true belief. Thus, since the JTB (which Magnus has attained) account is said to be sufficient for knowledge, and since Magnus intuitively does not have knowledge that two kids snuck in, then it follows that the JTB account is seriously challenged. Notice the similarities between this case and the Phony Professor case above.
Since the counterexamples above seems to be an instance of a justified true belief that does not result in knowledge, it follows that epistemologists need to change their account of knowledge from the JTB account. The natural approach to this problem would be to try and find some fourth condition that can be added to the JTB account of knowledge to define knowledge. This condition—whatever it is—is often called ‘warrant’. Warrant is generally considered to be a condition that is reliant on something external to the believers thought process. Some epistemologists would say that a belief is warranted if the believer came to believe it due to a reliable process. In the case above, Elek would not satisfy this warrant condition since a generally unreliable source (phony Professor Smith) prompted him to believe that the closest living relative to a tyrannosaurus rex is a chicken. However, note that Elek has no control over whether Professor Smith is a reliable source of information or not. The reliability of Professor Smith is external to Elek and thus whether Elek has achieved knowledge is not just dependent on what is going on in Elek’s mind, but it is also dependent on how the world is outside of his mind. Contemporary epistemologists often distinguish between externalist, theories and internalist theories. The externalist will say that the attainment of knowledge is dependent on something mind-external to the believer while the internalist says that all the necessary conditions of knowledge are accessible to the believer. Much of contemporary epistemology is focused on the debate between internalists and externalists as well as the goal of defining justification and warrant.
Comprehension Questions
Note for Instructors
Epistemology, from my experience, is a hard area of philosophy to teach. Students do not generally have experience thinking about how to think or reason, instead they may have simply been told how they are supposed to reason. Furthermore, students have pretty much certainly not given much thought about the definition of the word ‘knowledge’. Students will often think that questions related to what knowledge is are silly, they may suggest that you go ahead and look the answer up in a dictionary. I believe that I have found a few easy methods to 1) help students figure out what epistemology is and 2) help them realize why it’s useful.
Regarding 1), I recommend breaking epistemology down into a few different questions and then stating that the main goals of epistemology are to answer these questions. For example, I have stated that the two fundamental questions of epistemology are “what counts as knowledge?” and “what do we know?” For the first question I then dive into the literature regarding JTB and Gettier cases and I explore skepticism for the second. I am an epistemologist, so I know that the domain of epistemology is much broader than that; however, less is often more. It is often useful to introduce a topic to students bit-by-bit since introducing everything all at once is confusing. For example, if I told students that epistemology relates to the definition of knowledge, skepticism, norms of inquiry, norms of assertion, modality, mental states, pragmatic considerations, and more, than students would probably leave the classroom just as confused about epistemology as they were when they entered. Furthermore, I don’t think that it is useful to simply describe epistemology as “the theory of knowledge” as most do. Epistemology is so much more than the conceptual analysis of knowledge. In fact, epistemology is fundamentally normative. I think that students should learn about the normative aspects of epistemology from day one (after all, we ought to follow epistemic norms).
Regarding 2), I think it is important to help students realize that they are ignorant about the contents of the areas of epistemology that you are teaching. For example, if you are teaching the definition of knowledge, then it would likely be helpful to get students to realize that they are using the term ‘know/knows’ inconsistently. For example, you may ask your students to list a few things which they know. A student may say something like, “I know that my dad drives a Camry,” to which you could reply “but do you know that your dad has not bought a new car today and is waiting to surprise you the next time you visit?” You can then tell your students that this possibility of error always existed; however, the term ‘know/knows’ only seemed inappropriate when you brought up the defeater. Or alternatively, you could ask students what they know, and—assuming they brought up something that they cannot know with full certainty—you can then ask them if they know that they would lose the lottery if they bought a ticket. You could then explain that the odds of them being wrong are perhaps equally low in both cases; however, we only think that we lack knowledge in one of those cases and it’s unclear why. To finish off here, I want to say that showing students that epistemology is useful does not necessarily mean that you need to show them that epistemology can change the world. You simply need to show them that epistemology is a study which at least attempts to answer some interesting questions.
I will now spend some time giving advice on how to explain some of the specific concepts in this chapter that my students have had trouble with.
Many students get confused by the distinction between knowledge-that and knowledge-how. I believe that the source of this confusion is the fact that examples of knowledge-how all sound like propositions. If I say, “Tim knows how to play the Trumpet,” then somebody could reply, “no he doesn’t.” So, to many students, it may seem strange to say that knowledge-that cannot be judged to be true or false. It is thus important that you distinguish between playing the trumpet and stating that somebody plays it. The former is an example of knowledge-how while the latter is an example of knowledge-that. To express this distinction, it may be worth explaining that somebody may very well know how the trumpet works but still be unable to play the trumpet.
I find that students can easily understand the concept of defining knowledge as justified true belief. Regardless, it is important to explain what a necessary condition is and then state that each of these conditions are conceived of as necessary. Furthermore, I find it incredibly useful to give examples. I highly recommend giving an example of a justified false belief, a justified true belief, and an unjustified true belief and having the students pick the examples apart to see what they intuitively think is necessary for knowledge.
Gettier cases can be notoriously difficult to teach to students. I have found that it is important to give a recap of the JTB account of knowledge at the beginning of a lecture on Gettier cases. Furthermore, I recommend straying away from the classic cases in Gettier’s essay from 1963. They feel a bit contrived and overly complicated, so I would recommend making your own cases which are a bit simpler and more fun. If you are going to give an example of a classic case, then I would give the example of Russell’s clock (Russell, 1948: 170-1) as I have found that students find that example easy to understand (compared to other classic Gettier cases at least). Finally, it is important to have multiple cases so that students can see the similarities between the cases.
Reading Suggestions
Primary Sources
Gettier, Edmund, “Is Justified True Belief Knowledge?”
Plato, Theaetetus
Secondary Sources
Feldman, Richard, Epistemology, chapters two and three
Marian, David, “The Correspondence Theory of Truth”
