# X: On Our Knowledge of Universals explained — The Problems of Philosophy

> Chapter companion for The Problems of Philosophy by Bertrand Russell.

## What happens

This chapter explores the distinction between knowledge by acquaintance and knowledge by description, focusing on universals. It argues that a priori knowledge deals exclusively with relations of universals, and that such knowledge does not depend on experience of particular instances. The chapter also discusses how we become acquainted with sensible qualities, relations, and resemblance, and clarifies that empirical generalizations require experiential evidence while a priori propositions do not.

## Themes in this chapter

### Universals and Particulars

The chapter centers on the distinction between universals (e.g., whiteness, relations) and particulars (e.g., sense-data), and how knowledge of universals is acquired through abstraction.

### A Priori Knowledge

The chapter argues that all a priori knowledge concerns relations of universals, and that such knowledge is independent of experience of particular instances, resolving earlier mysteries about its nature.

## Key lines

> All a priori knowledge deals exclusively with the relations of universals.

Every truth known independently of experience is about how universals relate to one another.

_This is the central thesis of the chapter, used to explain the nature of a priori knowledge._

> Thus although our general statement implies statements about particular couples, as soon as we know that there are such particular couples, yet it does not itself assert or imply that there are such particular couples, and thus fails to make any statement whatever about any actual particular couple.

A general a priori statement like 'two and two are four' refers to the universal 'couple' and does not depend on the existence of any specific pairs of objects.

_This clarifies how a priori knowledge can be universal without requiring empirical instances._

## Links

- HTML: https://www.betterreads.online/discover/the_problems_of_philosophy_se/chapters/x-on-our-knowledge-of-universals
- Book: https://www.betterreads.online/discover/the_problems_of_philosophy_se
- All chapters: https://www.betterreads.online/discover/the_problems_of_philosophy_se/chapters