Epistemology: The Theory of Knowledge
Philosophy ·The only true wisdom is in knowing you know nothing - Socrates
How do we define knowledge and how do we decide whether we know things that we claim to know. This is the branch of philosophy called epistemology. In this post I will discuss about the various theories of knowledge and end with a particular school of thought called Radical Skepticism which posits that knowledge is not at all possible in most of the situations.
The word know is used in many different senses. The one which we will be concerened in this post is called a propositional sentence - a sentence which declares a fact about the world. For example, earth rotates around the sun. This sentence is declaring a certain way the world is. So to know that the earth rotates around the sun, the world has to be in a certain way. That is to say that if the sun were to disappear somehow although the earth would not leave its orbit for about 8 minutes but the statement that the earth rotates around the sun would not be true right after the sun disappears. This brings us to the first ingredient of knowledge: truth. For us to know a proposition, that proposition has to be true. A corollary of this is we cannot know falsehood.
Knowledge requires truth
To evaluate the truth of a proposition is an entirely different issue. We have to consider the question of what are the things we can accept as source of knowledge. We will not discuss this issue in this post.
Next, suppose that we declare a proposition which is also true but we have not the slightest of belief in the proposition. Can we say that we know the proposition. This is a delicate subject, so we should consider an example. Suppose a flat earther says that the earth is round. Although the flat earther gets it right (sorry I am not a flat earther!), they do not really believe the proposition (being a flat earther) and hence they do not know the proposition. Thus the second essential aspect of knowledge is
Knowledge requires belief
It then seems that knowledge is just about getting it right. But our intuition says that there is more to knowledge than just to say a true proposition which one believes in. Consider this example. I attempt a multiple choice question and make an educated guess and it turns out that the answer is correct. So I selected a true propostion and I also believe it is correct because I made an educated guess. I have satisfied both the requirements of knowledge but do I really know? I don’t because afterall I guessed the answer for which I had no reasoning. So it was just a matter of luck that I got it right. This brings us to the third requirement of knowledge:
Knowledge required justification
In other words, if I cannot justify my proposition, I do not know it. It is also sometimes called the anti-luck intuition. So to know a proposition we must form a justified true belief (JTB). This is the so called classical account of knowledge and is found in Plato’s works. This theory of knowledge was accpeted for a long time until it was challenged by Edmund Gettier in 1963. He presented simple examples which satisfied the JTB requirement but intuition tells us that those scenarios cannot be counted as true knowledge. These are the so called Gettier problems. Gettier’s examples were very complicated but I will illustrate a simple Gettier case.
Suppose you use an electronic thermometer to measure your temperature. On a particularly unlucky day, you were drenched in rain and by the end of the day you felt feverish and your body also felt hot. You measured you temperature and it flashed $100^{\circ}$ F. So you took some medicine and in a few hours you recovered. Now in the morning, you notice that the thermometer was frozen at $100^{\circ}$ F and it did not work when you measured your body temeperature. Now what would you conclude about the proposition “My body temperature was $100^{\circ}$ F yesterday”? Can you say that you know this proposition. Let us analyse this situation. You felt hot and uneasy and hence you probably had higher than normal body temperature, so your body temperature was around $100^{\circ}$ F (that is to say that you had fever). So the proposition is true. You also believe the propositon because of the uncomfortable experiences. You were also justified in believing the proposition due to similar reasons you formed the belief. So you satisfy all the hypotheses of the JTB theory. And yet because the thermometer was not working, it was just a matter of luck that you happen to measure your temperature when you felt sick. Had you measured your temperature on a normal day, you would not form the belief. So our intuition tells us that in such a case, we do not know the proposition.
Gettier cases pose serious problem for the classical account of knowledge and unsurprisingly, many epistemologists have tried to remedy the JTB theory by adding/modifying the requirements so that it excludes the Gettier cases. It turns out that it cannot be done in a simple way. I will illustrate this with a naive attempt to remedy the situation. We see that the Gettier cases arise when we make certain assumptions about the sources of our justified true belief. For example, in the above situation, you are assuming that the thermometer works properly to form your belief and this leads to the Gettier case. So if we add the following fourth condition to the JTB theory:
The justified true belief must not be based on any assumptions,
then it seems that we have excluded the Gettier cases. Let us see what are the consequences. The consequences are devastating. Everything that we consider to be knowledge is based on some kind of starting assumption. For example, the proposition that I have two hands is true for me according to the JTB theory but the additional fourth condition turns it into falsehood because I made the assumption that my senses give me the correct information. That my experience of my hands is real and that I am not just a brain kept in lab culture being fed nutrients and with rods plugged into different parts of the brain giving rise to these experiences. This brings us to the very disturbing idea of radical skepticism. Before I discuss radical skepticism, let me just mention that it is not easy to get deal with the Gettier cases in a way that out usual intuition of knowledge is intact and Gettier cases are excluded.
Radical skepticism maintains that it is not possible to prove that all our experiences are not fake and that we are being fed our experiences much like the matrix movie. Metaphysically, this means that nothing that we experience can be taken to be true on the face of it. The profound implication of this argument is that, whatever we think we know may all just be one of the many fake experiences that we are having and thus we do not really know anything at all. Whatever argument you come up with to defend your position is doomed to fail in front of the skeptic because the skeptic will say that all argumentation that you do may also be part of the matrix. This is like proving the existence of god which is an unfalsifiable statement. It can never be proved or disporoved. But then we will always be in doubt whether we know anything at all. Note that skeptics are not saying that the all our experiences are fake and that we are really in a matrix, they ane not making any such claims. They are just saying that it is not possible to rule out this possibility and hence true knowledge is never possible.
Is there anything real? Is there anything which we know without reservations? Can we say anything about the reality of our own existence? These are the questions which are about the “reality” of ourselves and the world around us and falls under the philosophy of “ontology”. We leave the discussion on ontology for next time.