Today, we live in a world where we can access more information than ever before. But how do you know what is true and what’s not? How do you know that you even know something? For that matter, what even is knowledge? These are questions concerning Epistemology, the branch of philosophy concerned with knowledge that forms the very foundation of human understanding. Epistemology is the study of the nature, origin, and scope of knowledge and epistemic justification. In this video, I’ll do my best to clearly and easily introduce the subject and cover significant developments and concepts from past to present-day theory. Make sure to pay attention because, after all, without understanding knowledge and what it is, how can you coherently argue for and know for sure what it is you believe is true? The term “epistemology” comes from the Greek words “episteme” and “logos.” “Episteme” can be translated as “knowledge,” while “logos” can be translated as “argument.”

or “reason.” All the questions and tasks of epistemology can be sorted into two main categories which we’ll cover in-depth. #1. Determining the nature of knowledge. What is it? How do we distinguish between someone who knows something and someone who fails to know something? #2. Determining the extent of what we can know. How do we acquire knowledge, and are there limits to what can be known? So, what is knowledge? Knowledge, simply put, is a type of cognitive success. More specifically, it’s a familiarity, awareness, or understanding of someone or something, which may include objects (called acquaintance knowledge or ‘knowing by acquaintance’), skills (called procedural knowledge or ‘knowing-how), and facts (called propositional knowledge or ‘knowing-that’). Philosophers mainly focus on propositional knowledge as it deals with facts about the world such as ‘He knows that Seattle is in California’, ‘Cats are mammals,’

or ‘2+2=71’. (A proposition can be, of course, true or false.) Possible ways we may gain knowledge include our perception, introspection, memory, the testimony of someone else, and reason. The philosopher Emmanuel Kant detailed in his work A Critique of Pure Reason that knowledge can be categorized as ‘a priori’ or ‘a posteriori’. A priori knowledge means knowledge prior to any experience using only reason, i.e., I know that all bachelors are unmarried. A posteriori is knowledge posterior to, or following, sense experiences in addition to reason. For example, I know that the snow is white. Philosophers called empiricists believe that all knowledge is ultimately grounded upon experience, while philosophers called rationalists believe all knowledge is ultimately grounded upon reason. Since we’re mainly concerned with propositional knowledge, the scope is so broad that we need a general characterization of knowledge we can apply to any situation.

Traditional epistemologists generally agree that propositional knowledge has three core parts: belief, truth, and justification. The first main ingredient, if you will, of knowledge is belief, an acceptance that a statement is true or that something exists. For example, to accept the truth of the proposition “the sky is blue,” one must first believe that the sky is blue. If one has no beliefs about a particular matter, one cannot have knowledge about it. Next, is truth, or the idea that one’s beliefs are in accordance with reality or objective facts. To acquire true knowledge is to increase one’s true beliefs and decrease false beliefs. If one can’t acquire truths at all, then one has no knowledge. However, not all true beliefs constitute knowledge. For example, the philosopher Duncan Pritchard argued we could have simply had epistemic luck. Take this example. Imagine John believes he has a fatal illness because he’s a hypochondriac.

and can’t help but believe such things. However, it turns out that upon going to a doctor, he’s informed he does have a fatal illness. He was right, but it was simply a matter of luck. So, knowledge needs a third element, justification or why one has good reason for holding their beliefs. Only true beliefs arrived at in the right way can be considered real knowledge. Therefore, many philosophers up until the 20th century believed that justified true belief, or JTB, as a fully accurate description of the nature of knowledge. Unfortunately, that came tumbling down when philosopher Edmond Gettier in his influential 1963 paper entitled Is Justified True Belief Knowledge? argued that luck still played a role in knowledge despite one having JTB. Here’s an example of what’s now called a ‘Gettier case’ that seemly shows JTB is not true knowledge: Suppose a normally well-working clock on-campus stopped working at 11:59 pm last night and

is frozen. Twelve hours later, as I’m on my way to class, I glance at the clock and form the belief that it’s 11:59. My belief is true since the time is indeed 11:59, and my belief is justified. There’s never been any reason to doubt the clock is not working, and I cannot be blamed for basing beliefs about the time on what the clock says. However, it seems evident that I do not know that the time is 11:59. If I walked past the clock earlier in the day, I would have ended up with a false belief rather than a true one since the clock is frozen. To solve Gettier’s issues, we need to understand what justification is, specifically its nature and structure. So, let’s dive into that now. One of the most important aspects of deciding the nature of justification is to consider if it should depend on factors solely in one’s mind or consider external factors.

Internalism is the belief that justification depends solely on factors internal to the believer’s mind. Internalism is contrasted with externalism, which states factors outside of just psychological ones, such as perception, can be conditions of justification. The most significant externalist theory of justification is called reliabilism, put forth by philosopher Alvin Goldman in the 1960s. According to reliabilism, a true belief counts as knowledge only if a reliable belief-forming process produces it. This may include standard perceptual processes, remembering, good reasoning, and introspection. So if we have 20/20 vision that seems to line up with others' reports, that’s a good belief-forming process. However, philosopher Keith Lehrer provides this example which seems to upend reliability and externalism called Mr. Truetemp that goes along the lines of this: A man named Mr. Truetemp had a device called a tempucomp implanted into his brain during

surgery, which he was unaware of. This device accurately reads the temperature and causes a spontaneous belief about the temperature. Mr. Truetemp now has many true beliefs about temperature but doesn’t know their source or why he has them. His belief-forming process is reliable, but his beliefs are unjustified. The argument shows just because a process is reliable doesn’t mean it’s enough to justify beliefs formed during that process. But, what about internalism? If justification depends just on factors in one’s mind, this raises the question of how these factors and knowledge are structured? The two main theories of justification are called coherentism and foundationalism. Coherentism is the theory that justification is a relation of mutual support among many beliefs. Think of coherentism as a spider web where each belief is a section of the web, and its strength of staying intact depends on the strength of the surrounding areas in the web. The problem with coherentism is that a system of facts can be coherent, like facts about

a secret wizard underworld that fit together but be wrong. Coherentism is based on circular logic. Foundationalism, on the other hand, states that certain beliefs can be based on other beliefs. Think of a skyscraper where one belief is based on another below it. An example of foundationalism is Aristotle deducing that Socrates is mortal. There’s a logical real that states all humans are mortal. Socrates is a human and humans are mortal. Therefore, Socrates must be mortal. However, there is skepticism and issues with foundationalism, too. In fact, much of epistemological study throughout the centuries has been just to address epistemological skepticism solely. Epistemological skepticism is the view that we cannot know anything, or at least that we do not know as much as we think we do. Skepticism about the extent of what we can know is not a new idea, but began during the

Hellenistic period. Pyrrhonism associated with the philosopher Pyrrho involves skepticism that states we can’t know anything, including if we can know anything, and Academic skepticism dating from around 266 BC associated by Carneades that states that the only thing we know is that we know nothing. A significant argument against foundationalism and, in fact, the ability to provide a complete logical foundation for human knowledge as a whole is called the Regress Problem, also known as Agrippa’s Trilemma, attributed to the ancient Pyrrhonist skeptic Agrippa. The argument essentially states that any proposition supported by a belief can be endlessly (infinitely) questioned, resulting in an infinite regress of beliefs. John Pollock states the argument as such: ... to justify a belief, one must appeal to a further justified belief. This means that one of two things can be the case. Either there are some beliefs that we can be justified

for holding, without being able to justify them on the basis of any other belief, or else for each justified belief there is an infinite regress of (potential) justification [the nebula theory]. On this theory, there is no rock bottom of justification. Justification just meanders in and out through our network of beliefs, stopping nowhere. So, in the case of Socrates being mortal, one could ask what makes one human? We’d have to find another belief like all born from females are human. But then that leads to another question; how do we know all born from humans are human? And so on ad infinitum. Epistemological skepticism isn't just about just asking why for every premise. It also involves full detailed arguments to support its own premises. I’ll cover two notable skeptical theories. The first being Cartesian skepticism which philosopher Rene Descarte outlined in the first of his Meditations. The argument states that our perceptions are often inaccurate;

for example, we sometimes mistake being in a dream for real life. What if, hypothetically, an evil demon is tricking us into believing we’re in the accurate world when things are far different. The modern version of this is that we are perhaps a brain in a vat fed data that makes it seem we have hands, legs, and live in reality. Of course, the scenario is far-fetched but illustrates that our senses can tell us how things appear, but not how they are. Descartes attempted to refute his original argument but with his famous “Cogito, ergo sum” or “I think, therefore I am” statement. However, the philosopher David Hume showed with Humean Skepticism how if one were to show a way to trust our perceptions clearly, it still wouldn’t be enough to defeat epistemological skepticism. First is the issue of numerical vs. qualitative identity. For the most part, we all think the external world is stable, and we believe various things

we see persist throughout the day. If there’s a tree in my yard I see each day, I assume it’s still there if I’m not looking at it. This can be outlined as the following: I have had two sense-experiences of a tree: one this morning and one in the evening. The two sense-experiences were (more or less) identical. Therefore, it is likely that the objects that caused them are identical. Therefore, a single object – the tree – has been in my yard all day. However, Hume thinks arguments like this one suffer from an equivocation fallacy, an informal fallacy resulting from using a particular word/expression in multiple senses within an argument. Mainly the first use of the word identical refers to qualitative identity while the second is numerical identity. When we say that the objects that caused the two sense experiences are identical, we mean that there is one object, rather than two, that is responsible for both of them, which

renders the argument fallacious. This problem goes deeper than that. Not only is there no reason to believe objects we observe can persist day-to-day, but we have no reason to assume similar objects like other trees will persist either. We can outline the argument like this… The tree has always persisted in the past. Nature is roughly uniform across time and space and thus the future will be roughly like the past. (We might call this second statement the principle of the uniformity of nature or PUN.) Therefore, that tree will persist into the future. However, because this is an inductive argument, Hume states that we need to provide some additional proof that PUN is true. This is referred to as the ‘problem of induction.’ So we might make this argument to show PUN is true: PUN has always been true in the past. Nature is roughly uniform across time and space (and thus the future will be roughly like the past).

Therefore, PUN will be true in the future. However, this argument’s second premise is just PUN restated. Thus, it’s circular, meaning we haven’t solved the problem of induction, and thus skepticism about knowledge remains. At this point, you’re probably wondering if humanity has made any progress in knowing anything since the original Hellenistic skeptics. Could it really be that we truly know nothing despite centuries of writing, thinking, and arguing? Hume did offer a way out of the woods of global epistemological skepticism with the idea of mitigated skepticism. Mitigated skepticism admits that we will never know anything for 100% certainty, but perhaps we can have partial knowledge of things while still remaining open-minded and skeptical. One of the most promising responses today to global epistemological skepticism is called Bayesian Epistemology, which uses this idea of partial knowledge. Based on Thomas Bayes' work in probability theory, instead of having fixed beliefs about

propositions. With Bayesian Epistemology, we are constantly updating our beliefs as probabilities depending on evidence and context. In Bayesian Epistemology, belief is seen as a continuous phenomenon of degrees called credences. Credences we already have about reality before we begin to gather new evidence or information are what’s referred to as priors. Knowledge then is a combination of new information that updates our credences plus our already established priors. Yes, the idea of knowing something 100% is fully impossible, but we can have degrees of belief, some greater than others. We can know some things less reliably than others to form a framework of reality and truth. Of course, Bayesian Epistemology has its critics and skepticism, but this is perhaps the most promising theory that helps us understand what truth and real knowledge are as of recording this video. In conclusion, the study of epistemology is long from over and is both a blessing and a curse to humanity. We’re the only species that strives to understand our place in the

universe, why we’re here, and what our purpose is, if there’s one at all. Cognition has helped us come to dominate the planet but may also lead to the end of us if we don't continue to pursue and try to understand truth and knowledge. If you found any part of this video helpful, please like it and share it with others. Also, subscribe for more videos like it.

Epistemology in Philosophy Simply Explained (Past to Present Day Theory)

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