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Bedrock (“hinge”) propositions in On Certainty

Bedrock (“hinge”) propositions in

On Certainty

What they are (in Wittgenstein’s terms):

  • Certain propositions are “exempt from doubt”—they function like the hinges on which our questions and doubts turn. They are not upshots of proof but the background that makes inquiry possible.
  • These certainties belong to our “world-picture” and form the foundation of our language-games; they “stand fast” for us. They are typically wrongly expressed by saying “I know…”.
  • They’re historically and culturally conditioned: a community’s science and education fix many of them, and some can shift over time (Wittgenstein’s then-plausible moon example illustrates this).

Typical examples Wittgenstein uses (with § numbers):

  • “Here is a hand” (Moore’s example) / “I know that here is my hand” — treated as a framework certainty rather than a proof of the external world. (OC §§1, 18–25, 389–407)
  • “The earth existed long before my birth.” (OC §§84–92, 183–191, 201–203)
  • “No one has ever been on the moon.” (given the then-accepted physics/world-picture). (OC §108)
  • “My body has never disappeared and reappeared after an interval.” (OC §101)
  • “We are certain how letters are pronounced; that other humans have blood and call it ‘blood’.” (OC §340)
  • “It is reasonable to believe I have never been on the moon; that I have a nervous system and innards like other people.” (OC §327)
  • “I know my name is L.W. / “I am called …” treated as (near-)incontrovertible in practice. (OC §§328, 657)
  • “The earth is round; we shall stick to this unless our whole way of seeing nature changes.” (OC §§291, 299)
  • Everyday certainties such as “motor cars don’t grow out of the earth.” (OC §279)

Why they matter:

  • They enable meaningful doubt and investigation: if you try to doubt everything at once, the very practice of doubting collapses; inquiry needs fixed points. (OC §§341–346)
  • They guide what counts as evidence and reasonableness within a community’s practices (“bound together by science and education”). (OC §298)
  • They are not pieces of knowledge won by proof, but conditions for having knowledge-claims at all. (OC §§401–404, 415)

Plain-text sources (for Obsidian):
Wittgenstein, Ludwig. On Certainty (trans. G.E.M. Anscombe & G.H. von Wright) – PDF used above:
https://prawfsblawg.blogs.com/files/wittgenstein-on-certainty.pdf
Background on hinge/world-picture reading:
https://iep.utm.edu/witt-epi/