Knowledge: A Very Short Introduction

Very Short Introductions #400

by Jennifer Nagel

What is knowledge? Is it the same as opinion or truth? Do you need to be able to justify a claim in order to count as knowing it? How can we know that the outer world is real and not a dream?

Questions like these are ancient ones, and the branch of philosophy dedicated to answering them - epistemology - has been active for thousands of years. In this thought provoking Very Short Introduction, Jennifer Nagel considers the central problems and paradoxes in the theory of knowledge whilst drawing attention to the ways in which philosophers and theorists have responded to them. By exploring the relationship between knowledge and truth, and considering the problem of scepticism, Nagel introduces a series of influential historical and contemporary theories of knowledge, incorporating methods from logic, linguistics, and psychology, and using a number of everyday examples to demonstrate the key issues and debates.

Genres: Philosophy, Nonfiction, Science, Psychology, Education, History, Social Science

133 pages, Paperback

First published August 4, 2014

About the author

Jennifer Nagel (b. 1947), Canadian philosopher.

Reviews

[Lisa · Rating 5 out of 5]

I know I have read this book!

Or wait a minute. Do I really know that for sure? Starting out with the typical self-confidence of an avid reader, I all of a sudden am confronted with doubt. According to skepticism, there is absolutely no proof that I am actually doing what I think I am doing. I might be thinking that I am reading about knowledge while I am in fact just dreaming.

Or worse still, I might be tricked by an evil demon to think I am reading, while I am in reality doing something else. I could even be caught in a futuristic helmet of horror in the fashion of Pelevin’s virtual reality labyrinth:

“For those who resist the supernatural element of the evil demon story, there is a modernized scientific version available: just suppose that your brain has been removed from your body and connected to a supercomputer which simulates experiences of a coherent reality, sending signals along your sensory pathways.”

Right, I don’t even know that I am not part of the film Matrix, or whether I have actually seen that film at all, or just been offered the simulation of the film in my brain in a vat. Welcome to the world of The Helmet of Horror: The Myth of Theseus and the Minotaur.

Luckily, this highly depressing idea that there is nothing certain, and that I can’t know anything, is not the only theory on offer in this brilliant book on epistemology. Of course there are also more optimistic ideas, like Bertrand Russell’s common sense approach of the simplest explanation:

“The most likely scenario is that Lisa has read the book, since she knows the content!”

But of course any detective would object to the idea of the simplest explanation equating the truth.

Descartes offers another idea: I think, therefore I am, and know of my existence. But does it help to prove that I have read my book?

Locke helps me differentiate between different layers of knowledge: I intuitively know I have read this book, and I have demonstrative knowledge of it as I can refer to Locke’s ideas in it. I also have sensitive knowledge of it as I hold the book in my hands. Locke also says that knowledge is a tool to pursue happiness, and I can confirm the effectiveness of that idea: the neurotic feeling of non-knowledge the skeptics left me with is gone now he has given me three different ways of knowing that I have read this book, and I feel sure of my own existence (I think!) as well. Gone is the brain in a vat!

However, I move on to modern analysis of knowledge (while reading, or dreaming of reading or thinking of reading, or simulating reading to a brain in a vat), and I am back in doubt. Do I have real proof of knowing what I think I know, namely that I am reading a short introduction to epistemology? What if this is a special April’s Fools edition, and all the correct data is removed and replaced with nonsense? Then I think I know that I read one thing while it is in fact something entirely different.

Before I fall back into the depression of skepticism, the book offers a term that makes me feel better: reliabilism. After all, as it seems like a reliable text, referring to such topics as skepticism, rationalism, empiricism, analysis of knowledge and so on, it makes the content match my expectations.

I could also rely on the testimony of others. It would make my case stronger if for example my son came into the room and said:

“Ah, you are reading!”

That works as long as my daughter doesn’t enter the room, exclaiming:

“Oh, you are knitting!”

AHHH!

And then, finally, I am saved, there is a term I am confidently familiar with: contextualism! If I am sensitive to the context of certain facts, I can be confident that I know whether or not I am actually reading a book, by low standards. By high standards, I don’t actually know it.

As a conclusion, I know (by low standards) that this sounds unlikely, considering the topic and my rendering of it, but this is a highly entertaining and informative introduction into the exciting topic of knowledge and our approach to it. For anyone who thinks one can know what that is, good luck!

Highly readable! (If you can objectively say that you know you read it!)

[Maru Kun · Rating 5 out of 5]

‘Jack’ was used in the13th century to designate the average English peasant at the bottom of the social heap, as in “every man Jack”. The French had the same idea with “Jacques” being a common name in medieval France and the “Jacquerie” being the common French peasantry who would occasionally revolt and burn down a few castles before getting massacred by French noblemen with better armor.

“Jack” eventually began to prefix things that were a smaller version of other things – jack-fish, jack-bowl – and in the British navy “jacks” came to refer to smaller versions of flags or sails, known also as sheets. A novice sailor would not know his “jacks” from his “sheets”. And this is how we come to “not knowing jack-shit”.

Well, an increasing number of people in public life – mostly our elected representatives - clearly “know jack-shit” about pretty much everything and I’m quite sick of it. The parade of morons, bullshitters (in the philosophical sense, as discussed in ‘On Bullshit’), cretins and chancers in US and UK politics these days has to be seen to be believed. I would like to really know how people know something so I can begin to understand why they know practically nothing about anything.

This book seemed a good starting place and I was not disappointed. It is a very interesting review of the main issues in epistemology and quite thought provoking. I can now know how our elected representatives know so little in a much deeper and more satisfying manner. This will help fuel my anger towards these know-nothings, bringing me great personal satisfaction.

And if you read the book as a bonus, you'll know whether or not you really know the etymology of "jack-shit" as well. How about that!


There now follows my notes on some chapters of this book as I instantly forget most things I read unless I make the effort to write them down and refer to them occasionally. Below is intended only for masochists who can’t make the effort to stop here and reach for the TV remote:

Chapter 1: INTRODUCTION

The connection between knower and thing known is often overlooked. Unlike water or gold knowledge would cease to exist in the absence of sentient life.

Do not identify “knowledge” with facts; not every fact is an item of knowledge. Toss a coin in a sealed box and write out two claims “the coin shows head” and “the coin shows tails”. Both are facts and one is true, but we do not know the outcome of the coin toss. Knowledge requires access to a fact on the part of a living subject. Unlike water or gold knowledge always belongs to some individual or group.

A group can have knowledge that its individual members do not possess. An orchestra “knows” how to play Beethoven’s Ninth even though each individual member does not.

“To know” is one of very few words that appear in all languages (think, see, want, hear, say, I, you, good, bad, not, maybe, because, if, true, before, after are other examples; eat, drink, happy, sad, animal are examples of words that are not universal).

“To know that” is a factive construction along with “to realize that”, “to see that”, “to remember that”, that is it links a subject to a truth. It is different from, for example, “to think that” where the proposition thought need not be true. This dedicated link to truth is part of the essence of knowledge. Belief can also easily link to a false proposition.

Watch out for non-literal use of “to know” that can link to false propositions, often in a “projected” use into a past frame of mind when it seemed that the subject knew – e.g. “I knew I’d been picked for the team, but it turns out I wasn’t”.

Confidence matters to knowledge – if I am confident that I locked the door this morning I may “know” that I locked the door, otherwise I might just “think” I locked it. However if I am confident of a proposition for the wrong reasons I would fail to know it – but if confidently held true belief is not enough for knowledge, what else is needed? (see chapter 4).

Only true propositions can be known, but what is true? Is truth relative to the subject? Even if we take the view that objective truth exists, is it humanly knowable? Sceptics have raised doubts.


Chapter 2: SCEPTICISM

Can we really trust our senses? Or might we be dreaming? Or might we be a “brain in a vat” (a ‘BIV’ apparently) being fed sense impressions by a mad scientist (or possibly a team of virtual reality developers at Sony - this seems much more credible to me).

Stoic epistemology draws a distinction between impressions and judgments: we receive sense impressions then judge what they are. Knowledge is wise judgment; you know something when a sense impression is so clear and distinct you could not be mistaken as to its nature.

Sceptics agreed with this stoic outline, but argued that you could never be certain that you are not mistaken. Sense impressions are always fallible and hence knowledge is impossible.

But how could sceptics be certain that sense impressions were always fallible (how could they “know” this if no one knows anything?!) - this reasoing leads to Pyrrhonian Scepticism.

A concern of Scepticism is the “criterion of truth” – the rule that figures out what to accept as known compared to accepting things randomly. But how do we know we have selected a correct criterion of truth? If we use the criterion itself to judge it aren’t we just using circular reasoning? Pyrrhonian Sceptics drew attention to this problem without claiming it would never be solved. Instead they suspended all judgment, generating doubt any topic by, for example, thinking bout how things may seem from different viewpoints – animals v human, different cultures etc.

If a Pyrrhonian Sceptic was hungry, would he suspend judgment on whether it eating would satisfy his hunger and starve? Apparently not – behavior can be guided by instinct, habit and custom rather than judgment or knowledge.


G E Moore’s challenge to Scepticism

G E Moore challenged Scepticism in a public lecture in 1939 by holding up his hands and saying “here is one hand, and here is another”. He explained that these were external objects and drew the logical conclusion that external objects actually exist. A great moment in epistemology – I wish I’d been there.

Moore insisted that he knew he had hands but refused to produce as proof that this would be the case. He proposed shifting the burden of proof over to the sceptic.

Moore claims to know without proof that he has hands but he does not claim that a person can never prove that he has hands. For example, a sceptic who thinks Moore’s hands are artificial might examine them and stick a pin in them to see if they bleed and so satisfy his concern. However Moore does not think that there is an all-purpose strategy for proving his hands exist to dispel all future doubts.

Moore is trying to highlight the philosophical nature of the claims of the sceptic – that there is no such thing as knowledge; that there is no all-purpose proof for any claim to have knowledge – so that it can be contrasted with the ordinary claim that he knows he has hands. The parallel is with mathematics. where some basic claims are taken as axioms not themselves in need of proof.

Moore says that we should be alarmed by someone making the controversial philosophical claims of Scepticism without being able to prove them. In contrast we should not feel such resistance to someone who claims to know a simple observable fact about the environment, such as having a pair of hands.

Bertrand Russell’s Inference to the Best Explanation (‘IBE’)

Philosophers have tried to identify more precisely the claim the sceptic is trying to make while constructing a positive defense to common-sense claims to knowledge.

In Russell’s IBE points out that there is a large gap between admitting that something is logically possible and concluding that we cannot rationally rule it out. For example, it is logically possible that, when you think you are stroking your cat, your are not doing so. Perhaps you are just dreaming? Perhaps your cat is not really a cat but a robot cat? How can we rationally rule out these alternatives?

Russell notes that there are rational principles other than the rules of logic narrowly conceived that can be used to rationally rule out the sceptics alternative explanations. In particular, a simpler explanation is rationally preferred to a more complex one: there is a single real cat who is responsible for the sense impressions of meowing and the feel of fur.

Challenges to IBE

IBE is a rational strategy, but is it conclusive grounds for knowledge rather than just rational belief? A detective investigates a murder. The butler hated the victim, the knife was found in the Butler’s room and the victim’s blood on his shoes. IBE suggests the Butler did it, but perhaps he is being framed by the housemaid?

Why is IBE a better explanation of the world than Brain-in-a-Vat (‘BIV’)? If you really were a brain being fed sense impressions by Sony virtual reality developers wouldn’t they try and send us coherent sense impressions consistent with an world of external objects anyway?

The Brain-in-a-Vat debates

Vogel argued that the basic spatial structure of the real world is much simpler than the spatial structure of a BIV virtual reality, making the real-world hypothesis as better way to explain our experience. But is there a better response to the sceptics BIV argument showing that it is not just implausible but wrong?

Semantic Externalism says that the meanings of words do not come from images or descriptions that individual speakers associate with them but from causal chains connection us to things in the world around us. What a modern scientist now knows to be H2O Shakespeare only knew of as water. However both parties have had the same experience seeing and tasting the liquid, and so mean the same thing when they use the word “water”. No one alive still knows Napoleon but if we talk about him we can trace sources with the right type of causal links back to people who know him and to the man himself.

Hilary Putnam tried to refute the sceptic’s BIV hypothesis with Semantic Externalism by arguing that the sentence “I am now a brain in a vat” couldn’t be true for anyone who understands the sentence, as a creature who only ever experienced virtual reality could not mean what we do by the word “vat” because such a creature had only ever interacted with simulated images of vats and his word “vat” cannot refer to something physical in the world beyond the simulation. Our capacity to make sense of the sceptic’s hypothesis is a sign we are in the real world and can understand what a vat is through our causal chains of connection to words describing the world around us.

Criticisms of Putnam include: maybe our sceptical problems are even bigger – maybe words now don’t mean what we thought they did; maybe you are a brand new BIV – some clever Sony developers kidnapped you asleep as after you had made the required causal connections to words (including, crucially, vat), popped your brain in a vat and similated a virtual world so convincing you never thought you’d left the real one. (If anyone could do this, Sony could).

Better off being a Brain-in-a-Vat?

David Chalmers pointed out that although a BIV might be experiencing pixels in virtual reality, was such experience really any less a “true” experience than that of atoms in the real world? From outside the vat we may say the BIV is reading a virtual book but from the BIV’s perspective it is true he is reading a book in his environment. Quantum mechanics showed us the ultimate nature of reality is very different from what our perceptions told us, but so what? Similarly would our experience in a virtual world really be effected if we found out we were a BIV?

Chalmers agrees with the sceptic that the BIV scenarios cannot be ruled out, but fights back against the suggestions that most of our beliefs are false in such a situation.


Staying out of reach of the sceptic

Given the sceptic raises doubts about everything you say in any case, there is not much hope for finding common ground with him as a basis for convincing him he is wrong. Why not try and stay outside his reach?

Timothy Williamson suggests that scepticism looks appealing because it encourages a healthy critical ability to double check individual things by suspending judgment and then seeing if they fit into the rest of what we know. But the process goes to far, as once we have suspended too much and brought into doubt the reality of the whole outside world we have no resources left to support any reasonable belief. (Note to self – this does sound like many conspiracy theories, which require an explicit or implicit suspension of a whole host of common sense beliefs in order to justify themselves).

Chapter 3: RATIONALISM AND EMPIRICISM

Pre-modern thinkers took the universe to revolve around humanity and sought to gain knowledge of nature by finding parallels between us and the heavens seeing reality as a symbolic work of art composed with us in mind. By 16th century this idea was endangered by discoveries such as the Copernican system and Galileo’s observation of moons circling Jupiter. We no longer expect there to be any special human significance to natural facts and expect to gain knowledge through systematic open minded observations of nature rather than the analogies and patterns which appealed to pre modern thinking even though pre-modern ideas – such as the Sun circling the earth – may fit more easily with our sense experience.

Descartes

In Meditations Descartes applied systematic Scepticism to question all his prior opinions. At the end of the first Meditation he establishes the first truth that can be known with utter certainty, the fact of one’s own existence (“I think, therefore I am”). In later meditations he reconstructs a new world view based thereon (with some help from God, useful given the rather narrow foundations).

In the Third Meditation Descartes questions what it was that enabled him to know this first fact of his own existence. He sees nothing more than “…a clear and distinct perception of what I was asserting”. He adopts this as a general rule for establishing this as a basis for knowledge and proceeds to defend it.

Without deciding whether or not they are real, Descartes notices differences between his ideas. Some differ in what they represent (angels, men, the sun, the sky, God) and in their apparent origins. Some seem to be invented – a hippogriff - and some, such as the idea of truth, seem innate. Some come from external things – the idea of a warm fireplace.

Among all his ideas Descartes identified one that stands at the top of the scale – the idea of God as an infinite and perfect being. Descartes reasons that this idea could only have come from God himself. Some commentators think this argument – from the idea of a perfect God to the existence of God is BS. But once God’s existence is established Descartes has his source for the clear and distinct ideas that form a basis for knowledge, as a perfect and benevolent God would not have installed defective innate ideas in us.

Descartes still has some work to do under this scheme, starting with explaining error. We are at risk of error when we make judgments on the basis of what is obscure and confused. If something is confused we should analyze into in clear mathematical or geometric terms- and so Rationalism was born, with abstract concepts at the heart of our pursuit of knowledge,

Human error can still arise, but this is due to human freedom to accept ideas that are less than clear and distinct.

But why did God give us obscure and confused bodily sensations along side our innate brilliant and perfectly accurate mathematical and abstract ideas? God also gave us an imagination, that is not simply reading the clear and distinct ideas of the intellect but is oriented towards the bodily senses. Our sensations and imagination serve the interests of the body and soul taken together. Sensations like hunger, pain, scent and color help ensure bodily survival which a benevolent God would have wanted to protect.

The Empiricism of John Locke

Locke’s ‘Essay Concerning Human Understanding’ sought to ‘search out the bounds between opinion and knowledge’ by using his ‘historical , plain method’ to style the natural operations of the human mind. Humans could not claim certainty nor attack others in matters of opinion or faith.

Locke questioned Descartes and the rationalists claim that we have ideas innate ideas: a baby could recognize its mother long before knowing the rationalist’s logical propositions such as ‘…tis impossible for the same thing to be, and not to be…’. Rather Locke proposed that the mind was a “tabula rasa”, a “blank slate” whose ideas came from two sources, the sensation of outer things and reflection on mental activities. Impressions on the mind from sensation and reflection can be combined to form more complex abstract concepts like justice, property, government or new ideas and inventions.

Locke noted that differences in defining and understanding key terms often frustrated debate around moral or political matters. He defined knowledge as ‘the perception of the connection and agreement, or disagreement and repugnancy, of any of our ideas’ and identified three ‘degrees’ of knowledge.

“Intuitive knowledge” is what we have when we immediately grasp agreement or disagreement of some ideas (‘that is a circle, not a triangle’). With “demonstrative knowledge” the mind sees agreement or disagreement between ideas through a chain of connecting ideas. “Sensitive knowledge” is not concerned with general truths or relations between ideas but with the existence of particular objects which we experience.

For Locke knowledge was a tool for the pursuit of happiness. Judgment was also such a tool but one which does not give us certainty but only probability, although in many cases probability high enough that we can treat it as practically certain.

We can contrast Descartes focus on the importance of abstract, innate ideas with Locke’s focus on experience and observation. Descartes has a “first-person” approach where the clearest instance of knowledge do not depend on anything external while Locke pays greater attention to observations including of himself and others. This difference developed into epistemological focus on “internalism” or “externalism” discussed in chapter 5.

...CONTINUED IN THE COMMENTS

[Shivam Sharma · Rating 4 out of 5]

one of those moments in life when you are confused between your stroke of genius and your transcendental bewilderment is when you read a book that makes you say "i think i just crossed the edge". not in a spiritual or Utopian way.
no. its not about that.
but when you stumble upon the notion that whatever you know this far might just be a hoax....a lie you told to yourself a long ago and made yourself believe it....or just as well someone else did it for you (or to you)....it even might have been an idea that has tumbled down from the hierarchy of the ages and found a rather comforting place in your mind.
do i have a hand?? how can i be sure?? how to prove myself that i am not dreaming right now. or even better, i might have been slipped into coma decades ago....and all this is nothing but a fragment of my imagination as truth eludes me.
has my brain turned into jelly?
how to know that a fact you 'believe' to be the truth (and therefore qualifying to be your knowledge) is in fact the truth? how sure are you??? 50%...70%...99.99%?????
even the person who buys a lottery ticket and knows for a fact that he stand 99.99% chance of loosing the game, still won't give up. 'you haven't lost till you've actually lost"
what then is knowledge?
as i reached the flyleaf there was but one thought in my mind:
"what do i know?????"

[Heleen.A.H · Rating 3 out of 5]

knowledge, I have always been seduced by this word. the love for gaining knowledge, for knowing the reality and also for being somebody who knows about enormous things, has emerged within me since the beginning of my adolescence. without knowing the exact meaning of knowledge, I started to read any book that I had.
but then someday, when I was in sorrow and pain, I asked myself why I am doing that? what am I searching for? what is knowledge? and after reading some different ideas I observed that knowledge doesn’t have any specific definition. then I reached a conclusion that nearly nothing has a specific definition. even if we define something in a scientific way ( in a constant way with evidence) we can't be sure about and it can change in any time.
these thoughts and some other factors like an American tv series (Westworld) changed my love for gaining knowledge to the love of knowing about knowledge and then led me to this book. a very short introduction about knowledge which starts with epistemology and some philosophical background of knowledge (skepticism, rationalism, empiricism, testimony, internalism and externalism, etc) and it distinguishes between knowing something and believing something. it tries to analyze what is real and factual and what could count as knowledge about that fact!. now I have an idea about knowledge and I can define it in many ways, and also in my own way which is: knowledge is the link between us and reality of the world. and reality is anything that affects ourselves, our minds and our lives.

[فادي · Rating 3 out of 5]

أظنّ أنّ الكتب التي تكون "مقدمات" لعلم ما يجب أن تتمتع بخصلتين:
1- البساطة
2- الإلمام
لأنّ المتلقي قد ينفر من الموضوع إذا لم يجد ما يشدّه إليه، مهما كان أصل الموضوع مهماً.
وكلمة "المعرفة" جذّابة، وتغري بالبحث والاطلاع، لكني أعتقد أنّ هذا الكتاب لم يقدمها بصورة جيّدة، وكان أقرب لصورته الأكاديمية منه إلى صورته التبسيطية.
الفصل الذي أعجبني حقاً وشعرت أن فيه إفادة هو [ فصل الشهادة ] الذي في طيّاته يكاد يتطابق مع منهجية أهل الحديث في أخذهم الأحاديث عن الرواة ممن عاصروهم أو لم يعاصروهم ( علم الجرح والتعديل يعني).

برأيي- ليس مناسباً للمبتدئ - وإن كان يقدّم كذلك، الأجود منه ( كتاب مدخل إلى نظرية المعرفة تأليف أحمد كرساوي )

[Steve · Rating 5 out of 5]

If you would like a very short introduction to knowledge (epistemology) then this 116 page book is just perfect. Maybe someone with a deep philosophy background would have some reason to carp about it, I don’t know (haha). But as a lay reader it felt like this was a very clear explanation of various schools of thought over the centuries.

By the way, the author Jennifer Nagel (a philosophy professor and an engaging writer who can easily speak Plain English) is *not* related to Thomas Nagel, a very famous philosopher.

[Moh. Nasiri · Rating 4 out of 5]

کتابی در باب معرفت شناسی فلسفی
دویدن پی آواز حقیقت
Knowledge=Epistemology

این کتاب را در بلینکیست گوش دادم و برای درک معرفت شناسی و نحوه درک ما از جهان پرداخت است
اینکه درک و معرفت ما از جهان به چه شکلی هست نویسنده با بررسی دیدگاه های مختلفی از فیلسوفان یونان(پروتاگروس و افلاطون) و چند قرن اخیر(دکارت،جان لاک...) سعی می کند به این سوال جواب بدهد اینکه باور و معرفت چه نسبتی با هم دارند
آیا واقعیت وجود دارد یا ما رویا می بینیم

همانگونه که قلاب سلبی و ایجابی همیشه برای درک مفاهیم و تئوری پردازی از ما دست بردار نیستند به همین ترتیب درک آفاقی(آبجکتیو) و انفسی(سابجکتیو) جهان و حقیقت یا سوژه و ابژه به تعبیر استاد مصطفی ملکیان بر ذهن ما لنگر انداخته است .تا زمانی که مرزی بین بدن ما و جهان کشیده شده است این نگرش بیرون و درون وجود خواهد داشت سفر مکرربیرونی و درونی از دید ناظر اول شخص.
افلاطون معتقد بود که حقیقت آبجکتیو هست و در حالیکه پروتاگوراس می گفت سابجکتیو هست

به نظرم برای درک مقدماتی موضوع معرفت شناسی کتاب خوبی هست هر چند به دیدگاه برخی ار فیلسوفان نپرداخته هست
کتاب هایی از این دست در حوزه علاقمندان فلسفه ذهن و علوم شناختی قرار می گیرند

کلمات کلیدی
Objective Vs. Subjective
Externalism Vs. Internalism
skepticism
Perception
Empiricism
Rationalism
Contextualism
Testimony
Reductionism
Intuition

متنی درخصوص دویدن پی آواز حقیقت در ویرگول نوشتم
https://virgool.io/@m.nasiri/%D8%AF%D...

[Joshua · Rating 3 out of 5]

Interesting. Upon digging into it, it is clear that the concept of knowledge and being knowledgeable is actually quite feeble. Do you really know? How? Can you be sure you aren't dreaming, or that this isn't an illusion? It often depends on the source, context, available evidence and what sub genre of epistemology you most subscribe to.

Personally, I both agree and disagree with snippets of the epistemology and philosophers mentioned in this book, but I don't really care about any of that. I care about what it means to obtain and retain knowledge, to be knowledgeable and wise, and how to pass on knowledge to future generations. I have come to understand that the more you know, the more you realize how much you don't know, and that the storage within our minds is finite. An endless stream of sensory information passing through our brains continuously and only the stuff of importance will stick, so spend time learning about the things you you are genuinely interested in and passionate about, and let everything else disappear into the universe.

[Michael Scott · Rating 3 out of 5]

Overall, a good and short introduction to the  notion of knowledge and to epistemology (all philosophical problems related to knowledge). Complement by reading also the chapter in https://plato.stanford.edu/entries/epistemology/.

The author covers primarily the safe, well-known aspects of knowledge; she avoids the modern questions of the influence of values, gender (especially feminist views on the matter) on acquiring knowledge, but still follows contextualism, social epistemology (when the social contwxt may play a role in how knowledge is acquired and expressed). Would have also liked a deeper analysis of rhe knowledge as available through modern technology; addressing onky Wikipedia seems insufficient. 

+ Covers core concepts: knowledge, belief, thought, opinion, and knower.

+ Covers sources of knowledge: perception, reflection, memory (very little, much more could be said about cognitive sciences), and testimony (could be linked to the justice system notiona of civil and penal codes). Introspection is minimally covered. 

+ Covers skepticism (scepticism) as strict traditional invariantism, modern variant brain in a vat, rationalism and epiricism, internalism and externalism, reductionism in testimony, contextualism, modern variant interest-relative invariantism (never heard of IRI before). 

+ Covers origins and types of ancient epistemology, including types of skepticism, stoicism.

+ Covers origins and variants of realism, starting with René Descartes, and of empiricism, starting with John Locke. 

+ Covers Gettier's challenge, causal theory of knowledge. 

+ Covers internalism and externalism, Nozick's tracking theory, the generality problem concerning the method for tracking truth. 

+ Covers ancient and modern views of testimony, including several types of reductionism. 

+ Covers standards, contextualism and IRI, various ways to use them to interpret limit-cases, and their relationship with skeptical views of the same cases. 

[Sara Sheikhi · Rating 3 out of 5]

Cute little book that gives a good introduction to the current stance in the field of knowledge. It could have been a bit less decorated with text that appealed to recognition of situations and have more structure. But overall it is a cute book that I probably have to re-read in order to understand (not gain knowledge, it seems so hard now) better.

[حسين الضو]

اللي يعجبني في سلسلة أكسفورد هذي، إنها ليست مجرد "تلخيص" للفكرة مثل ما نشوف في برامج الكبسولات المعرفية. هذي السلسلة تتناول الموضوع انطلاقا من الوضع الراهن له، أي أنها أشبه بما يعرف بـ
Literature review في الأطروحات الأكاديمية

ومنها ينطلق إلى أبعاد أخرى تتعلق بالموضوع سواء كانت من ضمن تاريخ الأفكار أو أي شيء آخر. وهذا متوقع طالما كتاب السلسلة هم من الأكاديميا

[Blair Hodges · Rating 4 out of 5]

Spoiler alert:

"We still do not fully understand what knowledge is" (116).

A fun, readable book on epistemology. Tells a concise history from pre-Modern to Modern thinkers, up to present theories of what it means to "know" and how we know it.

[Berr · Rating 5 out of 5]

I know it you know it :)

short yet thorough history and story of knowledge theories as well as knowledge possibilities.

I know I must highly recommende this book :)

[Pavlogreen]

Afilada, grácil en su escritura, clara en sus explicaciones y con tono distendido, Jennifer Nagel ofrece en Knowledge: A very short introduction una de las mejores obras si uno tiene interés en esta rama tan enrevesada de la filosofía que es la epistemología. Nagel, lejos de complicar la ya difícil teoría, la hace accesible e incluso apasionante. Tras esta lectura mi agrado por la disciplina ha aumentado y ahora dispongo de unas cuantas herramientas conceptuales nuevas y referencias bibliográficas valiosas para continuar profundizando en la materia.

[Shko · Rating 4 out of 5]

This small book took me on a journey from the ages when arguments about knowledge firstly appeared, and then coming all the way to modern times. It helped me to healthily second-guess (I do say that, because while reading, I realized what being skeptic is like) the very basic matters about knowledge, e.g., skepticism, testimony, standards, how points of view matter (especially first and third), decisions and opinions.

After collecting arguments from each side trying to create an invariable definition for knowledge, and their worries and falsities, I feel that knowledge is no such thing to be defined by only a factor and not it's opposite, but it is a feeling that has been balanced between every factors, and their oppositions, mentioned in the book, per se, it is something that could be in between internal feelings and external facts. After all for better analyzation of knowledge, I think it's better to discriminate human made objects from what are called natural objects, because it is possible for someone to know all about humanities creations without fully-knowing the source from which the object has been altered and modified to create what is knowable.

Since it's my first fully philosophical arguments read, It is hard to evaluate it and see whether whom I should recommend it for, but overall it is a small pocket book, with an abstract for -maybe- every intriguing issues about knowledge, so I can say that it is a good point to start digging into the matter of knowledge.

[Rooster · Rating 2 out of 5]

Rather frivolous semantics discussion disguised as an academic subject matter

This may well be my bad. I was expecting more of an ontological discussion -of the ultimate nature of “reality” (so called “truth”) and how we can/can’t have access to it. This was a epistemological/semantics discussion on what is “meant” by the word “knowledge”. That seems to me to be a frivolous undertaking. It becomes an investigation on what we “mean” by knowledge and not an investigation of knowledge itself. It seemed to me evident that the meaning ascribed would largely be context derived -but that the root of the notion was the relationship between “truth” and human access to it. That investigation would require going well beyond semantics and taking a cross-disciplinary approach heavily informed by physics, psychology and neuroscience, notably. That was wholly absent, even if the last few pages seem to lead there. So, can’t fault the author if this is the state of epistemology, but I can fault the subject for (in my view) being grossly myopic and limited. Sorry.

[David · Rating 4 out of 5]

Worth a read. Nagel briefly but clearly explains a number of approaches to knowledge and belief, including classic and contemporary work. She discusses a number of classic problems and some proposed solutions, while being honest that there are no universally accepted approaches to the topic. Props to Nagel for at least briefly engaging with science, such as physics for ontology and psychology for how the mind works. It was shallow engagement, but vastly better than none (such as Robert Audi's turgid Epistemology).

I appreciate that while this is grounded in the Western tradition, she does in a few places compare and contrast to other systems, mostly Chinese and Indian. These systems sometimes paralleled, anticipated, or followed Western ideas, but there are also some differences.

I was most disappointed by the almost-absent treatment of probability. To any modern scientist, probability is fundamental for knowledge. No scientist who's even moderately reflective ever thinks they actually establish anything as "true" or "false"; rather, they may say things like they reject the null hypothesis at 95% (or 99.7%, or so on). Thus it appears that classic and much modern epistemology is missing the boat when it comes to how science approaches the idea of knowledge, which is rather a large boat to miss given that science is our only reliable way of establishing knowledge.

Nagel does briefly mention probabilities when discussing the idea of using thresholds in a reliabilism approach (pp. 53–54). However, she still weirdly uses a binary where there is "knowledge" and "not knowledge", and the (seemingly impossible) task is to decide what probability the dividing line should be at. This is absurd. There is no such thing as The One True Knowledge, so we just have degrees of probability.

She also gets hung up on the weird problem of the lottery example (p. 54), where if you require a probability threshold of 99.9% for knowledge, then after buying a lottery ticket with a 1/1000 chance of winning you could "know" that you lost before the results were announced, which most people would disagree with. (Suggest a higher probability, and we can just make a less likely lottery.) She suggests that this is an insoluble puzzle, which seems weird. It helps to consider a Bayesian approach here. If my prior is 50% (say, flipping a coin and checking for heads) and then I receive information boosting my reliability to 99.9% (a quick glance at the actual outcome), it's perfectly reasonable to say that I "know" I got heads (or not). However, if my prior is 99.9999% (say, that my ticket will lose a one-in-a-million chance lottery), then I will not say that I "know" the result until my credence has significantly changed. "Knowing" the result means a reliability substantially above an ignorant prior.

Anyway. Philosophy often seems stupid, but this book does a good job being engaging and non-stupid.

[Hom Sack · Rating 5 out of 5]

Excellent introduction to Epistemology.

For the visual learners, her series on Wireless Philosophy is excellent too:

Epistemology: Introduction to Theory of Knowledge - YouTube (https://www.youtube.com/playlist?list...)

as well as the much longer series of lectures:

Jennifer Nagel - Frege Lectures 2019 - YouTube (https://www.youtube.com/playlist?list...)

[Junie Rönnqvist]

En kort bok om kunskap som förklarar många olika områden på ett enkelt och lättförståeligt sätt! (Läste för min kurs i kunskapsteori)

[AFP · Rating 1 out of 5]

(0.5) literal nonsense, no way bro is that invested in some of the most round about absurd justifications of even lamer chicken and the egg ahh crap

[Abigail Franklin · Rating 3 out of 5]

Fewer philosophers, more farmers. Nagel made concepts approachable, but the concepts are stupid.

[loïs]

🥱

[Cassandra · Rating 2 out of 5]

It was ok. I enjoyed the discussion at first, but soon realized the book wasn't going to discuss much beyond "what does it mean to know something?" It got pretty boring and seemingly pointless from my view. I guess I would take the blue pill.

I've always been curious about this series of short introductions and how they compare to Wikipedia. Well, the Wikipedia entry on knowledge is broader and very different. This book goes into more detail on theories and different perspectives, so narrower and deeper.

[Cecilia · Rating 4 out of 5]

A starting point to learn about theories of knowledge and epistemology.

[Magzhan · Rating 4 out of 5]

This is my first review in English and Goodreads. I want to do it simply, just for practicing my English outputting.
There were some questions keep hunting me last days. Is there a truth exists? If there is a truth, how could I get it properly. Can I figure out the truth by myself barely through sitting-and-thinking? Then this book turned up. My thoughts about this book and my questions may follow.
1.There IS a truth of human.
2.Skepticism is a autoimmune disease, we need it, but should not be trapped in it.
3.The proper way to get the truth is the empirical one, because of the limitation of the individual.
4.Knowledge is not as same as the truth, it is something to approach the truth.
5.I prefer the objective truth, because, in general we human beings are all the same. In other word, there are lots of consistencies among all of us.

[Brent Pinkall · Rating 5 out of 5]

An excellent introduction to epistemology. Nagel does what few academics are able to do--write clearly and succinctly. It takes real skill to explain something as complicated as epistemology in such simple terms. What's more, Nagel does an excellent job defending and critiquing the various positions she covers. She presents each position in the best, most persuasive light possible before attacking it through the mouths of its critics. I've thought about many of the issues she discusses but haven't known the technical terms for these different views. I'm glad to know them now and also to have learned about some new ways of thinking about knowledge that I haven't considered before. If you're new to epistemology, this is a great place to get your bearings.

[Hank Hoeft · Rating 4 out of 5]

Knowledge: A Very Short Introduction, Jennifer Nagel's primer on epistemology, takes a fairly esoteric branch of philosophy and succeeds in making it comprehensible to the uninformed layman. My only complaint is that when it comes right down to it, no one yet has a completely satisfactory idea of what "knowledge" really is. But Nagel does an excellent job of explaining the strengths and shortcomings of the many different schools of thought that have been generated since ancient Greece.

[Mohammed Kotb · Rating 2 out of 5]

A mind boggling journey in the concept of knowledge at which it ended in total mess. It only strengthened my conviction that the death of epistemology should be declared. We better invest our energy in deciphering the problem of consciousness. And whether consciousness is related to something higher than our neural mantle, a quantum ether perhaps.

[Mahdieh Ebrahimi · Rating 5 out of 5]

صادقانه بگم کتاب رو به بدترین شکل ممکنه خوندم شاید اگر تمرکز بیشتری داشتم دریافت بهتری ازش میداشتم. اما کتاب خیلی خیلی خوبی بود. معرفی خوبی است راجع چگونگی کسب دانش و اینکه اصلا دانش چی هست. سیر تاریخی سوال هم خیلی خوب مطرح شده.

[David Gross · Rating 4 out of 5]

Very clearly and precisely written. An excellent overview of the past and current philosophical problems concerning knowledge.