The Problems of Philosophy

In this chapter, Russell breaks down universals into how they are discovered: by acquaintance, description, or another method. Knowledge of universals by acquaintance includes concepts like colors, tastes, or textures. These are learned through the intake of sense data across platforms. Russell explains these concepts as sensible qualities. Universals can also be known through connection. Russell uses the example of a page of a book. A person recognizes the page by the connections between its various parts. A page is made of paper and contains both words and blank spaces. Many pieces of sense data work together to form a singular concept.

Humans can apply universals by connection across myriad contexts. It is used to understand time and space, as well as resemblance. Humans can also recognize both the similarity and difference between two shades of green, finding a universal quality between the two.

Russell returns to the equation 2+2=4 to establish how priori knowledge relates to universals. The equation is reliant upon several universals. Both “two” and “four” are examples of universals. The interaction and relationship between the universals form the meaning of the equation.