Emerson links fear with a lack of knowledge or understanding. His point is that uncertainty can make people imagine dangers more readily, while greater knowledge may clarify what is genuinely threatening and what is based on assumption. The statement therefore treats ignorance not simply as an absence of information, but as a condition that can shape perception and judgement.

In The American Scholar, the idea fits Emerson’s wider emphasis on independent thought, learning and intellectual confidence. He encourages people to examine the world directly rather than submit passively to inherited beliefs or anxieties. The claim is deliberately broad and should not be read as saying that every fear is irrational; fear can also arise from real danger. Rather, Emerson stresses that ignorance can intensify fear by leaving uncertainty unexamined. Knowledge, inquiry and experience can therefore help distinguish justified caution from anxiety produced by misunderstanding.