4.063 explained

What happens

Themes in this chapter

• Nonsense and Meaning

  The simile illustrates that a proposition without a sense corresponds to nothing, emphasizing that sense must be determined before truth-value can be assigned.

• Critique of Traditional Philosophy

  Wittgenstein directly critiques Frege's conception of truth as a property of propositions.

Characters to notice

• Frege

  Referenced for his terminology of truth-value and his view that 'is true' or 'is false' are predicates of a proposition, which Wittgenstein criticizes.

Key passages

• “To the fact that a point is black corresponds a positive fact; to the fact that a point is white (not black), a negative fact.”

  A black point represents a positive fact, while a white point (the absence of black) represents a negative fact.

  Wittgenstein uses the black-and-white paper simile to illustrate positive and negative facts.

• “But to be able to say that a point is black or white, I must first know under what conditions a point is called white or black; in order to be able to say “ p ” is true (or false) I must have determined under what conditions I call “ p ” true, and thereby I determine the sense of the proposition.”

  Just as one must know the criteria for calling a point black or white, one must first establish the conditions under which a proposition is true, which defines its sense.

  Wittgenstein emphasizes that determining the truth-conditions of a proposition is prior to assigning truth or falsity.

• “The verb of the proposition is not “is true” or “is false”—as Frege thought—but that which “is true” must already contain the verb.”

  Truth or falsity are not predicates added to a proposition; rather, the proposition itself already includes the verb that makes it true or false.

  Wittgenstein rejects Frege's view that 'is true' functions as a predicate.