# 5.02 explained — Tractatus Logico-Philosophicus

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

## What happens

Wittgenstein distinguishes between arguments of functions and indices of names, arguing that confusing them underlies Frege's theory of propositions and functions. He illustrates with examples from Russell's notation and the name 'Julius Caesar'.

## Themes in this chapter

### Critique of Traditional Philosophy

Wittgenstein critiques Frege's theory of meaning by exposing the confusion between argument and index.

### Limits of Language and Thought

The distinction between argument and index highlights how logical notation can mislead understanding.

## Character check-ins

### Mr. Wittgenstein

Author of the Tractatus, presenting the distinction between argument and index.

### Bertrand Russell

Referenced for his notation '+c' as an example of indexing.

### Frege

Criticized for confusing argument and index in his theory of meaning.

## Key lines

> It is natural to confuse the arguments of functions with the indices of names.

People often mistakenly treat the arguments of functions as if they were indices attached to names.

_Wittgenstein identifies a common logical error._

> The confusion of argument and index is, if I am not mistaken, at the root of Frege’s theory of the meaning of propositions and functions.

This confusion, I believe, underlies Frege's entire theory of meaning for propositions and functions.

_Wittgenstein directly links Frege's error to this confusion._

## Links

- HTML: https://www.betterreads.online/discover/tractatus_logico_philosophicus_se/chapters/5-02
- Book: https://www.betterreads.online/discover/tractatus_logico_philosophicus_se
- All chapters: https://www.betterreads.online/discover/tractatus_logico_philosophicus_se/chapters