# Epistemology/What is epistemology

What is epistemology and why should you learn it? Well, epistemology is the branch of philosophy that deals with knowledge and surrounding concepts such as justification, belief and credence, and is tightly interconnected with many other areas of philosophy such as metaphysics, ethics and philosophy of science, just to name a few. Epistemology aims to explain how we know the things we do, whether that's mathematics, science, history, or even just the things that we see or hear right in front of us. Another important project of epistemology is in characterising when and why we should believe some things and not others. Therefore, epistemology is not only a central area in—and useful introduction to—philosophy as a whole, it also helps us to know the limits and nature of our knowledge, helps guide our intellectual practices by showing us when we are truly justified in our beliefs, and it helps us to develop key philosophical skills such as critical thinking and intellectual humility.
Epistemology is a broad and exciting area of philosophy as represented by the range of issues covered in this textbook. One of the central questions of epistemology has been "what is knowledge?" and as a result, the first section is dedicated to analysing the concept of knowledge. It is important to note with regards to this section that there are actually many kinds of knowledge. For example, I could say "I know Bob, I've met him many times before" or I could say "I know blue, I've been lucky enough to be acquainted with that colour in all its shades!" In both these examples, I am expressing a type of knowledge called acquaintance knowledge. Likewise, I could say "I know how to ride a bike, that's easy." In this example, I am expressing a type of knowledge called ability knowledge. Neither of these two types of knowledge are the focus of the analysis of knowledge in section I. The analysis of knowledge has historically focused on the analysis of propositional knowledge. This is the type of knowledge we have when we know of the truth or falsity about a proposition. Examples of propositional knowledge are "I know that 2 + 2 = 4" and "I know that Bob is a philosopher". Analysis of this kind of knowledge has a long history but remains a difficult and contentious question in epistemology and philosophy more broadly.
Another argument important throughout the history of philosophy is whether experience or reason is the true source of knowledge. In section II, we will explore the historical debate between Rationalists and Empiricists in the early modern era about how we gain knowledge of the world by examining perception and reason as sources of knowledge. Philosophers today not only consider perception and reason as sources of knowledge but have begun to also consider other sources of knowledge including memory, introspection and testimony. Testimony is different to the other sources of knowledge we have talked about so far in that testimony has an inherently social component, it relies on whether or not and under what circumstances we should trust others. Building on this, we will consider the social practice of science as a source of knowledge. This consideration of social epistemology will be echoed and developed further in section IV.
I think that one of the first thoughts many students of epistemology have is about scepticism and the possibility that we are living in the Matrix or that we are a "brain in a vat" as most philosophers use as such a sceptical example. Indeed, Descartes' methodological doubt and corresponding evil demon thought experiment led to perhaps the most famous line of philosophy ever written or spoken: "I think, therefore I am." Section III will consider the problem that radical scepticism poses for epistemology by exploring solutions to two defining problems in epistemology. The first is Agrippa's trilemma which threatens the idea that any of our beliefs could possibly be justified and the second is sceptical scenarios we have talked about above and "the closure principle".
In section IV, we will explore some exciting problems that are posed by the social context of knowledge. How can we understand widespread disagreement in many areas even amongst equally educated people and how should we respond to it? Do we have any responsibilities to others in our intellectual lives and can we even commit epistemic injustices against others? Could such epistemic injustices even rise to the systemic level? Can the social structure of inquiry bias the knowledge we acquire and how can we alleviate this problem? Should we trust experts, how can we know who the experts even are, and what problems do fake news and the internet play for these questions? These are all questions asked in the areas of social and applied epistemology.
Hopefully this introduction has given a taste of the issues in epistemology covered in this textbook and created an appetite for the content of the rest of the book, as well as epistemology more generally. Even more so, hopefully this book is useful for those interested in philosophy and epistemology and provides an accessible introduction to the subject.