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Tractatus Logico-Philosophicus · Chapter

5.51 explained

Wittgenstein explains how the N-operator, when applied to a set with one proposition, yields its negation, and when applied to a set with two propositions, yields the joint negation (neither p nor q).

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Wittgenstein explains how the N-operator, when applied to a set with one proposition, yields its negation, and when applied to a set with two propositions, yields the joint negation (neither p nor q).

Free preview opens on this chapter — companions, themes, and character notes appear beside the text.

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Themes in this chapter

  • Logic and Tautology

    The N-operator defines how truth-functions are built from elementary propositions, grounding logical necessity in tautology.

Characters to notice

  • Mr. Wittgenstein

    Author of the Tractatus, presenting the N-operator as a fundamental logical operation.

Key passages

  • “If ξ has only one value, then N ⁡ ( ξ ‾ ) = ~ p (not p ), if it has two values then N ⁡ ( ξ ‾ ) = ~ p . ~ q (neither p nor q ).”

    When the set ξ contains a single proposition, the N-operator gives its negation; when it contains two propositions, the N-operator gives the conjunction of their negations.

    This illustrates how the N-operator can generate all truth-functions by joint negation.