Emerson means that lived experience provides the basic material from which people develop knowledge, language and understanding. Just as a dictionary supplies words and meanings, life supplies the experiences that allow ideas to become concrete. Observation, work, relationships and encounters with the world give substance to concepts that might otherwise remain abstract.

In The American Scholar, the phrase forms part of Emerson’s argument that education should not depend on books alone. Reading is valuable, but scholars also need direct experience if they are to think independently and express ideas with clarity. Emerson therefore treats action as an essential part of intellectual development. Experience enlarges the range of references from which a person can think, write and judge. The quotation condenses this argument into a simple metaphor: life itself is a continuing source of meanings through which knowledge can be interpreted and communicated.