Tractatus Logico-Philosophicus · Chapter
5.151 explained
Wittgenstein introduces a formal schema for calculating the probability that one proposition gives to another, based on the ratio of shared truth-conditions.
What happens
Wittgenstein introduces a formal schema for calculating the probability that one proposition gives to another, based on the ratio of shared truth-conditions.
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Follow the arc while readingThemes in this chapter
- Logic and Tautology
The probability ratio is grounded in the logical structure of truth-conditions.
Characters to notice
- Mr. Wittgenstein
Author of the Tractatus, presenting a formal definition of probability between propositions.
Key passages
“Suppose in a schema like that above in No. 5.101 T r is the number of the “ T ”’s in the proposition r , T r s the number of those “ T ”’s in the proposition s , which stand in the same columns as “ T ”’s of the proposition r ; then the proposition r gives to the proposition s the probability T r s : T r .”
If we count the truth-conditions (T's) in a truth-table for proposition r, and then count how many of those same truth-conditions are also T's in proposition s, the ratio of the latter to the former is the probability that r confers on s.
Wittgenstein defines logical probability as a ratio of shared truth-conditions.
