An Essay Concerning Human Understanding

Classical liberalism refers to a political branch that emphasizes the free market and civil liberties. Locke is considered a founder of classical liberalism, and his political writing influenced major movements such as the American Revolution.

Empiricism is a theory asserting that knowledge is acquired through sensory experience. This epistemological premise has foundations in ancient Hindu philosophy as well as Greek medical science. Locke proposed that the human mind is a blank slate that sensory experience fills, providing the bedrock for consciousness.

Epistemology is the philosophical theory of knowledge. The field attempts to understand what humans know and how they obtain knowledge.

Locke uses the word “essence” to refer to the observable qualities that define a species, genus, or type. Real essence applies to tangible things, including substances.

Like real essence, nominal essence is composed of the qualities of an idea. However, nominal essence refers only to the abstract. Locke provides the example of gold. Its physical qualities make up its real essence, but the complex idea of gold and our human relationship with it form the abstract “nominal essence.”

Locke suggests that two major processes contribute to knowledge. The first is sensation, and the second is reflection. The latter refers to reflecting on ideas presented through sensation. Reflection creates a deeper understanding of the world and its workings.

The world presents various stimuli, which humans receive through sensory experience. This information is translated into knowledge. Locke refers to this process as “sensation.”

This term refers to the major thesis of Locke’s work—the mind as a blank slate. This philosophical theory suggests that all humans are born with minds free from ideas or thoughts. The mind fills with ideas as a person experiences the world through the senses.