# 6.1264 explained — Tractatus Logico-Philosophicus

> Chapter companion for Tractatus Logico-Philosophicus by Ludwig Wittgenstein.

## What happens

Wittgenstein distinguishes between significant propositions, which assert something and are proven by showing it is so, and logical propositions, which are themselves forms of proof. He states that every logical proposition is a modus ponens presented in signs, and that modus ponens cannot be expressed by a proposition.

## Themes in this chapter

### Logic and Tautology

Discusses the nature of logical propositions as forms of proof and modus ponens

### Limits of Language and Thought

Highlights the inexpressibility of modus ponens by a proposition, showing a limit of expression

## Character check-ins

### Mr. Wittgenstein

Author of the proposition

## Key lines

> The significant proposition asserts something, and its proof shows that it is so; in logic every proposition is the form of a proof.

A meaningful proposition makes a claim, and its demonstration confirms that claim; but in logic, each proposition itself constitutes a demonstration.

_Clarifies the contrast between empirical propositions and logical ones_

> Every proposition of logic is a modus ponens presented in signs. (And the modus ponens can not be expressed by a proposition.)

Each logical proposition is a rule of inference (modus ponens) shown through symbols, but this rule itself cannot be stated as a proposition.

_Emphasizes the inexpressible nature of logical form_

## Links

- HTML: https://www.betterreads.online/discover/tractatus_logico_philosophicus_se/chapters/6-1264
- Book: https://www.betterreads.online/discover/tractatus_logico_philosophicus_se
- All chapters: https://www.betterreads.online/discover/tractatus_logico_philosophicus_se/chapters