## Wednesday, August 15, 2007

4.063 A picture to explain the concept of truth: a black spot on white paper; one can describe the form of the spot in that one can answer for each point on the sheet whether it is white or black. To the fact that a point is black corresponds a positive fact, to the fact that a point is white (not black), a negative one. If I indicate a point on the sheet (a Fregean truth-value) then this corresponds to the assumption that is proposed for judgment, etc. etc.

In order though to be able to say whether a point be black or white, I must first know when one calls a point black and when one calls it white; in order to be able to say “p” is true (or false), I must have determined under which conditions I call “p” true, and thus I determine the sense of the proposition.

The point at which the simile breaks down now is this: we can indicate a point on the paper without knowing what white and black are; to a proposition without sense however nothing whatsoever corresponds, because it signifies no thing (truth-value) whose properties are called false or true; the verb of a proposition is not “is true” or “is false”—as Frege believed—but rather that which “is true” must already contain the verb.

Anscombe (note 1 on pp. 105-106) says that Wittgenstein’s reference to “the Fregean Annahme” (assumption) is really a reference to what Russell says about Frege in Principles of Mathematics Appendix A, §477. She argues that Russell and Wittgenstein get Frege (in “Function and Concept”) wrong, and mistakenly attribute to him a technical meaning of ‘assumption.’ Assumption in this sense means something like the assertion of a proposition as either true or false, so that the truth-value of the proposition can be thought of as a verb, meaning the checking of an imaginary box next to “is true” or “is false.” Anscombe notes that Frege did say that the verb of the proposition is “is true” in the Begriffsschrift, but he never said this of “is false” and he rejected this earlier view of his in “Sense and Reference.”

Anscombe pp. 152-153 notes that Wittgenstein’s talk of determining the conditions under which I call a proposition true sounds like verificationism to some people, but it is just a reference to truth-conditions. The emphasis is on logic, not epistemology.

Ostrow (p. 84): “What is important in the notion of the assumption for Wittgenstein is that it brings out how the possibility of saying something determinate about the world depends logically on a prior inner connection between language and reality, a form that is common to both. At the same time, a clear understanding of this idea makes evident that we have no holds on that form apart from our capacity to make true and false statements about the world.”