An Essay Concerning Human Understanding
by John Locke
Book I. No Innate Principles
Book I of the Essay is devoted to an attack on nativism or the doctrine of innate ideas.
The doctrine of innate ideas, which was widely held to justify religious and moral claims, had its origins in the philosophy of Plato.
Furthermore, travelers to distant lands have reported encounters with people who have no conception of God and who think it morally justified to eat their enemies. Such diversity of religious and moral opinion cannot not be explained by the doctrine of innate ideas but can be explained, Locke held, on his own account of the origins of ideas.
If propositions were innate they should be immediately perceived—by infants and idiots (and indeed everyone else)—but there is no evidence that they are. (p29)
Locke allowed that some ideas are in the mind from an early age, but argued that such ideas are furnished by the senses starting in the womb: for instance, differences between colours or tastes. If we have a universal understanding of a concept like sweetness, it is not because this is an innate idea, but because we are all exposed to sweet tastes at an early age.
Book I is intended to reject the doctrine of innate ideas proposed by Descartes and the rationalists
Book II Of Ideas
Every idea is derived from experience either By
Sense
- direct sensory information
- the red color of a rose, the ringing sound of a bell, the taste of salt
OR
Reflection
- “the perception of the operations of our own mind within us, as it is employed about the ideas it has got”.
- one’s awareness that one is thinking, that one is happy or sad, that one is having a certain sensation
Sense and Reflection provide Ideas, which are objects “before the mind,” not in the sense that they are physical objects but in the sense that they represent physical objects to consciousness.
Ideas are simple or complex
Simple ideas are derived from sense experience
Complex ideas are derived from combination of simple ideas. Therefore complex ideas can be broken down into simple ideas.
The complex idea of a snowball, for example, can be analyzed into the simple ideas of whiteness, roundness, and solidity (among possibly others), but none of the latter ideas can be analyzed into anything simpler.
In Locke’s view, therefore, a major function of philosophical inquiry is the analysis of the meanings of terms through the identification of the ideas that give rise to them. The project of analyzing supposedly complex ideas (or concepts) subsequently became an important theme in philosophy.
Primary and Secondary qualities of physical objects
Primary qualities include size, shape, weight, and solidity, among others
Ideas of primary qualities resemble the qualities as they are in the object
Secondary qualities include color, taste, and smell
Ideas of secondary qualities do not resemble any property in the object; they are instead a product of the power that the object has to cause certain kinds of ideas in the mind of the perceiver.
Personal Identity (contested)
Personal identity consists of continuity of consciousness.
One is the same person as the person who existed last week or many years ago if one has memories of the earlier person’s conscious experiences.
Association of ideas
Ideas, Locke observes, can become linked in the mind in such a way that having one idea immediately leads one to form another idea, even though the two ideas are not necessarily connected with each other. Instead, they are linked through their having been experienced together on numerous occasions in the past.
The psychological tendency to associate ideas through experience, Locke says, has important implications for the education of children.
BOOK III Of Words
Role of language in human mental life
Words, Locke says, stand for ideas in the mind of the person who uses them. It is by the use of words that people convey their necessarily private thoughts to each other.
The problem is, if everything that exists is a particular, where do general ideas come from?
Locke’s answer is that ideas become general through the process of abstraction. The general idea of a triangle, for example, is the result of abstracting from the properties of specific triangles only the residue of qualities that all triangles have in common—that is, having three straight sides.
Book IV The nature and extent of human knowledge
It is possible to know that the three angles of a triangle equal two right angles if one knows the relevant Euclidean proof. But it is not possible to know that the next stone one drops will fall downward or that the next glass of water one drinks will quench one’s thirst, even though psychologically one has every expectation, through the association of ideas, that it will.
These are cases only of probability, not knowledge—as indeed is virtually the whole of scientific knowledge, excluding mathematics.
Humans would be incapable of dealing with the world except on the assumption that such claims are true.