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On Certainty

4.16  ·  Rating details ·  4,249 ratings  ·  123 reviews
Written over the last 18 months of his life & inspired by his interest in G.E. Moore's defense of common sense, this much discussed volume collects Wittgenstein's reflections on knowledge & certainty, on what it is to know a proposition for sure. ...more
Paperback, bilingual, TB1686 , 194 pages
Published September 6th 1972 by Perennial/Harper & Row (NYC) (first published 1969)
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Ahmad Sharabiani
Über Gewissheit = On Certainty, Ludwig Wittgenstein

On Certainty is a philosophical book composed from notes written by Ludwig Wittgenstein over four separate periods in the eighteen months before his death on 29 April 1951.

The book's concerns are largely epistemological (theory of knowledge), a recurrent theme being that there are some things which must be exempt from doubt in order for human practices to be possible, including the activity of raising doubts: "A doubt that doubted everything wo
Dec 28, 2011 marked it as to-read
Some interesting things that people are certain about:


You have an invisible friend who is the most important being in the world and responsible for everything that happens.


The great strength of science is that all its findings are provisional and subject to revision at any moment if new evidence comes in. This is why you should trust it.


Even 0.1% growth over a few tens of millenia would result in an economy bigger than the known universe. But, although it is impossible
David Katzman
Feb 03, 2009 rated it really liked it
I’m not…certain how I feel about this book. What I mean more precisely is…that…it is impossible for me to be certain how I feel about this book. In fact, it’s impossible for me to really be certain of anything whatsoever. According to Mr. Ludvig Vittgen-shhhhhhhtein, that is.

On Certainty was a rather enjoyable read despite the fact that it contained 676 numbered paragraphs of somewhat repetitive analysis. But if one is as fascinated by philosophy as I am, then it’s no bother. Some would say Witt
Aug 15, 2013 rated it really liked it
I will not be able to use "I know" in my vocabulary without first questioning my statement's certainty a hundred times. Would I be certain of my knowledge then? I might not be. Wittgenstein, in this book, uses short philosophical and linguistic reflections on "knowing" as a response to G. E. Moore's 1939 paper, “Proof of an External World”. He asks you to emphasize on "I believe" than "I know" whenever you "don't know", because when you think you "believe", and say that you "know", you actually ...more
Steven Godin
Second Wittgenstein book I have read, that was far less challenging that the first.
A deeply insightful collection of notes that effectively gets into the mind of this influential and complex philosopher. Wittgenstein writes on the theme of common sense, as he attempts to address the debate between radical skepticism and GE Moore's claim to know various facts with certainty. He has always been difficult to read and truly grasp, but this book reads relatively straightforward, making it a good plac
William West
It seems to me that Wittgenstein is trying, with this very late work, to answer the questions raised in his Tractatus in the terminology he employed in his mid-period, that of the language games of the Blue and Brown Books and Philosophical Investigations. With On Certainty, finished two days before the author's death, I think Wittgenstein arrives at surprisingly Kantian conclusions.

Wittgenstein begins both this work and the Tractatus with an inquiry into that of which he can be certain. In the
Oct 27, 2007 rated it it was amazing
Recommends it for: Sully
Shelves: philosophy
Strange, wonderful little book. It has its dull moments, but there are moments of blazing light.

How certain am I, that I have never been to Jupiter?
"It is as certain as any grounds I could give for it."
Apr 18, 2010 rated it really liked it
What can we be certain of? The only thing Wittgenstein is certain of is that there's something fishy about philosopher G.E. Moore's assertions "I know that that's a tree" or "I know that here is a hand" or "I know that I have never been far above the earth's surface." Wittgenstein is terribly perturbed by these statements but doesn't know quite why. It has something to do with the fact that the only people who ever make such statements are philosophers; the rest of us "know" such things by simpl ...more
Aug 16, 2018 rated it it was amazing
Shelves: books-bought
Reading Ludwig Wittgenstein is a series of moments when one thinks of language and what it truly means. 'I think there is a tree' and 'there's a tree' is a vast difference, that can fit an entire universe. Or at the very least in the world of Wittgenstein. For me, I 'think' I understand Wittgenstein, but the lasting impression he has on me as a writer is to write as clearly as possible, but without surrendering the poetics in a specific description.

For inspiration and getting my brain exercised
Erik Graff
Mar 05, 2009 rated it really liked it
Recommends it for: Wittgenstein fans
Recommended to Erik by: Bill Ellos
Shelves: philosophy
As recalled, this was my favorite volume of the very many produced by the clever fellows who have made careers out of his. Wittgenstein himself published very little, but an enormous body of works attributed to him have been culled from his correspondences, notebooks and students' notes of lectures and conversations.

On Certainty comes as close as Wittgenstein ever does to being a systematic philosopher rather than just playing at being a skeptic, phenomenologist, speculator or analyst of languag
Jun 06, 2011 rated it it was amazing
Shelves: philosophy
Wittgenstein always fascinates me. He is not easy to read unless you are willing to go into his terrain of mind. He has a different mind from most of us, above, on a meta level of what we call "things in life". This book questions all the things we take for granted in order to live, to the extreme extent of almost being silly. After the questioning, there is not much left to maintain the human life. I wonder how many people can overcome that void.
Theresa Macphail
Jan 19, 2011 rated it it was amazing
Shelves: philosophy
I love Wittgenstein for, if nothing else, his pithy writing style. I also find him helpful for thinking through my research data in terms of the relationship between certainty, uncertainty, and the production of knowledge. Worth it, even if you haven't read Philosophical Investigations.
Jul 16, 2018 rated it really liked it
Oh, how intolerable the notion of a perennially incomplete system of knowledge! And yet how fortunate I can commiserate with Wittgenstein, though we are separated by time.

At the foundation of well-founded belief lies belief that is not founded.
On Certainty, Ludwig Wittgenstein
Brandon Henke
Sep 02, 2015 rated it it was ok
Epistemology as linguistic analysis. The phrase "I know _" is more appropriately rephrased as "I believe _ to be so", that is, an expression of a degree of certainty regarding a proposition that is dependent on a specific frame of reference. That all judgments of "truth" ultimately rely on some faithful assumption is an important insight. And yet, I'd much rather read about the domain-specificity of skepticism and heuristics à la Nassim Taleb than proceed further down Wittgenstein's rabbit hole ...more
Aasem Bakhshi
Mar 06, 2013 rated it really liked it
Shelves: philosophy
At times tough, at times perplexing, at times dull. Its about language, not epistemology but kind of vague epistemic conjecture in undertones. Looks like a soliloquy but a wonderful little masterpiece.
Sep 23, 2014 rated it really liked it  ·  review of another edition
Facing multitudinous uncertainties as of late, I reached for philosophy to stem the tide of despair. On Certainty, perhaps was not the appropriate book to reach for. I remember why I had originally given it three stars four years ago: they are the notes of W on various strands of incomplete thoughts about as many aspects of certainty as he could think of, which means they were written in an aphoristic-style.

This is more me than W. I loathe aphorisms. It's not that I despise terseness, it's that
Dec 14, 2015 rated it really liked it
This book belongs to the last 1 1/2 years of Wittgenstein's life. In 1949, he visited the US at the invitation of Norman Malcolm and stayed at his home in Ithaca, NY. Malcolm goaded Wittgenstein to write about G. E. Moore's famous "defence of common sense." Moore claimed to know a number of propositions for sure. For example, Moore stated in "Proof of the External World" the following:

"Here is one hand, and here is another."

That quote by the way explains the cover with hands on it.

Here are tw
Jan 24, 2008 rated it it was amazing
Recommends it for: skeptics
i couldn't decide whether this book is for humans or space aliens. i guess it's for both.

wonderful wittgenstein. 90 excruciating pages (676 numbered sections) on whether G. E. Moore was justified in holding up his hand and saying, "I know that here is my hand." the second half is quite creepy to read, as he was dying of cancer while writing it. the dates are on the entries, with the final page written two days before he died.

127 - how do i know that someone else uses the words "I do
Ege Özmeral
Jun 20, 2019 rated it it was amazing
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Would it be extremely weird of me if I said it was a 'fun' read? As much as saying this amuses me, this was a really funny book, and I mean in a very positive and serious way. First thing Wittgenstein does to you, from the outset, is tear apart your cozy little way of thinking, and 'knowing'. I'll never 'know' anything the way I've known before, or at least I'll think a second more before I say I'm certain of something. Next, as you read and re-read and re-re-read almost every other sentence, yo ...more
Mar 13, 2014 rated it it was amazing
This was an excellent read. Wittgenstein's main works are, of course, the Tractatus and Philosophical Investigations, but some consider On Certainty to be his third major work. Unfortunately, On Certainty was not formally organized by Wittgenstein. It is more or less a collection of notes, which represent Wittgensteinian thought post-PI.

Some readers take Wittgenstein's stance in these notes to be sceptical. I personally don't sympathize with this view. If anything, Wittgenstein is starkly anti-s
Olli K
Feb 16, 2010 rated it really liked it
I read Tractatus Logico Philosophicus and On Certainty one after another and I must say that On Certainty is much more enjoyable to read than TLP. At least if you do not have any previous knowledge about philosophy.

I was happy to notice that this book was not so hard to read and gave the reader opportunity to form own opinions. At one point I even noticed that there was a flaw in Wittgenstein's thinking.

If you do not have any or very limited previous knowledge about philosophy and wish to read
David Williamson
Sep 14, 2011 rated it really liked it
I know I liked On Certainty, but that would be playing the language game properly, and not making a statement of fact, of this I can be certain but not know, of which I can be wrong but still believe...

This book sometimes feel like its a head on collision between philosophy and the everyday. What we can say and its implications within varied contexts, contexts that can never be nailed down. It's almost like what it would be like if an AI computer had a mental breakdown. Good stuff.
Michael Starks
Sep 02, 2012 rated it it was amazing
Recommends it for: everyone
Recommended to Michael by: nobody
On Certainty was not published until 1969, 18 years after Wittgenstein’s death and has only recently begun to draw serious attention. I cannot recall a single reference to it in all of Searle and one see’s whole books on W with barely a mention. There are however xlnt books on it by Stroll, Svensson, McGinn and others and parts of many other books and articles, but hands down the best is that of Daniele Moyal-Sharrock (DMS) whose 2004 volume “Understanding Wittgenstein’s On Certainty” is mandato ...more
Aug 06, 2015 rated it really liked it

This is a slim little book that Wittgenstein wrote toward the end of his life, in his characteristic numbered succinct paragraphs. It's good. Clear, somewhat repetitive (though that's only a plus because you never know when you're missing something in his hyper-compact writing), it tackles the perennial questions of uber-skepticism: can you doubt everything, even the existence of the world and my body?

Does the world exist?

The book was actually written in response to G.E. Moore's landmark
Dec 09, 2019 rated it it was amazing
As is always the case with LW, I'm finding it difficult to say precisely what I think is "valuable" here, and worry that Wittgenstein is being too quietist, but simultaneously have the feeling that LW is limning the conceptual boundaries of human thought like no one else has. Since his notes on this topic were not arranged to be published this can feel repetitive and disorganized, but his fundamental points about the nature of certainty/knowledge/doubt seem "right" to me, and make me wonder abou ...more
Oct 12, 2013 rated it liked it
Shelves: philosophy
Do we become more or less certain as we get closer to death? In Wittgenstein's case, judging from his notes during his final days, he was open to questioning even the most obvious and trivial facts. The book was published posthumously from notes compiled within his last two years alive in the early 1950s, and did not appear to a broader audience until nearly 20 years after his death.

The text was written mostly, but not exclusively in German. I benefited from having the German and English side-b
Sep 18, 2015 added it
Shelves: note, philosophy
"I did not get my picture of the world by satisfying myself of its correctness; nor do I have it because I am satisfied of its correctness. No: it is the inherited background against which I distinguish between true and false."
"All testing, all confirmation and disconfirmation of a hypothesis takes place already within a system. And this system is not a more or less arbitrary and doubtful point of departure for all our arguments; no it belongs to the essence of what we call an argument. The syst
Sep 24, 2011 rated it it was amazing
Amazing. Wittgenstein goes in circles a bit trying to get across his point (then again, these are his notes/journal), but this ranks among my favorite books of all time.
Robert Heckner
Jun 19, 2015 rated it really liked it
Wittgenstein is always worth reading.
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Ludwig Josef Johann Wittgenstein (26 April 1889 – 29 April 1951) was an Austrian-British philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.

Described by Bertrand Russell as "the most perfect example I have ever known of genius as traditionally conceived, passionate, profound, intense, and dominating", he helped inspire t

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“I am sitting with a philosopher in the garden; he says again and again 'I know that that’s a tree', pointing to a tree that is near us. Someone else arrives and hears this, and I tell him: 'This fellow isn’t insane. We are only doing philosophy.” 217 likes
“I act with complete certainty. But this certainty is my own.” 124 likes
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