An Essay Concerning Human Understanding | Study Guide

John Locke

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An Essay Concerning Human Understanding | Glossary


complex idea: (n) an idea put together in the mind from various simple ideas. Concrete examples include "man" and "horse"; abstract examples include "justice" and "ambition."

innate: (adj) present in a person at birth. Locke argues against the existence of innate ideas, claiming instead that all ideas are acquired through experience.

judgment: (n) the process of assessing the probability of a claim which has not been proven true or false. Many things we think of as knowledge are, for Locke, merely well-supported judgments.

maxim: (n) a short statement capturing a basic truth or rule. Locke argues that the role of maxims in knowledge-building is seriously overrated.

mode: (n) a type of complex idea which does not represent a substance in itself, but an abstract quality or attribute which a substance might have. The idea of a triangle, for example, is a mode because triangles are not physical substances, though a physical object can be triangular.

nominal essence: (n) the abstract idea denoted by a name. For Locke, a nominal essence is like a bundle of traits which all members of a group (e.g., all horses) have in common.

real essence: (n) the true essence of a thing, which gives rise to all its observable properties. Locke regards the real essences of things as generally unknowable.

reason: (n) the process of discovering new truths and finding connections between them. Locke is very cautious, even pessimistic, in his claims about the potential of human reason.

reflection: (n) the process whereby the mind observes its own patterns of thought. Reflection is, along with sensation, one of the two basic pathways by which the mind obtains ideas.

sensation: (n) the process of obtaining new ideas through the direct sensory impressions of the outside world. For Locke, this is one of two ways ideas arise in the mind, the other being reflection.

simple idea: (n) an idea which makes an immediate and unalterable impression on the mind. For Locke, basic sensory perceptions like "hot" and "cold" are the definitive simple ideas.

syllogism: (n) a formal rule or pattern for showing the validity of an argument. Unlike some academic philosophers of his time, Locke thinks syllogisms are usually more of a distraction than a help in reasoning.

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