In Part 4, Burke draws a distinction between the sublime and beautiful. The importance of defining these two qualities is inherent to understanding how human passion and the mind function. Humans are limited in their understanding. If they could follow the chain of all thoughts, they would discover everything leading back to God. However, humans can only conceive what they can take in through their senses. Therefore, any understanding of beauty and the sublime must be developed through the senses.

Association is a powerful way that humans interpret something as beautiful or otherwise. They find it difficult to separate their connections from the object. However, associations are not what makes something beautiful or sublime, because many things are first thought to be agreeable or disagreeable and then later discovered to be the opposite. Instead, Burke feels it is a better method to examine pain and how it manifests. While fear and terror are related, they have a different relationship to both pain and the sublime. Concepts which cause terror are related to the sublime. Fear, however, is more connected to pain and the body.