Epistemology

“If you know that here is one hand, we’ll grant you all the rest.” This deceptively simple proposition opens On Certainty by engaging with G.E. Moore’s famous “proof” of the external world. Moore claimed to know with certainty that “here is one hand” — but Wittgenstein asks: what does such knowledge really rest upon? The statement functions as a conditional surrender — if we accept certain basic propositions as known, the entire edifice of knowledge follows. But this reveals that our knowledge system requires starting points that are not themselves justified by other knowledge. ...

“From its seeming to me — or to everyone — to be so, it doesn’t follow that it is so. What we can ask is whether it can make sense to doubt it.” This remark cuts to the heart of epistemology: consensus is not truth. Even if something seems certain to everyone, this collective certainty doesn’t guarantee correspondence with reality. But Wittgenstein adds a crucial twist: the relevant question isn’t “is it true?” but “does it make sense to doubt it?” Some propositions are so fundamental that doubting them would undermine the very framework within which doubt operates. ...

“But 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.” This is one of the most profound observations in On Certainty. Our worldview (Weltbild) is not something we chose after careful verification — it was absorbed, inherited, taken on without explicit consent or evaluation. ...

“The propositions describing this world-picture might be part of a kind of mythology. And their role is like that of rules of a game; and the game can be learned purely practically, without learning any explicit rules.” Wittgenstein makes a stunning move here: our foundational beliefs are not scientific propositions but something closer to mythology. They function like rules of a game — rules that can be absorbed through practice without ever being explicitly stated. ...

“If you tried to doubt everything you would not get as far as doubting anything. The game of doubting itself presupposes certainty.” This is perhaps the most devastating critique of Cartesian skepticism ever formulated. Descartes attempted to doubt everything to find an indubitable foundation — but Wittgenstein shows this is structurally impossible. Doubt is not a freestanding activity. To doubt X, you must hold Y fixed. To doubt Y, you must hold Z fixed. The “game of doubting” requires pieces that don’t move. There is no view from nowhere, no Archimedean point from which all can be questioned. ...