John Locke and the Beginning of Empiricism

Rationalists claimed that knowledge is innate and therefore true knowledge lies within ourselves.

John Locke differed from these theories.

To prove his point, he takes an example of a child. A child from birth is like a clean slate (tabula rasa), hardly any ideas are present in the mind of a child. It is through experience that a child is able to know what he knows.

Snippet from the Philosophy Book

Further, he says that if ideas were ever innate, then a mentally challenged individual would have knowledge too, but that is not the case.

So how is true knowledge gained?

According to John Locke, experience. He proposes the Theory of Perception to explain. According to this theory, all knowledge comes from sensory experience. However, he admits the limitations of this theory:

First, it suggests that our perceptions of the world are subjective and depend on the individual’s sensory experiences. This means that different individuals may have different perceptions of the same object or event.

Second, Locke argued that our perceptions are not always accurate or reliable, as they are subject to various distortions and errors. For example, our perceptions can be influenced by our prior beliefs and expectations, or by various cognitive biases.

Finally, Locke’s theory of perception emphasizes the importance of empirical evidence in validating knowledge. He believed that our perceptions must be tested against the evidence of our other senses and corroborated by the experiences of other individuals in order to be considered reliable knowledge.

Snippet from Philosophy Book

He further proposes that experience is built by two types of Ideas; Simple and Complex.

Simple ideas are those that are derived from sensory experiences, such as the color of an object, its size, or its shape. These ideas are basic units of knowledge that are gained exclusively through experience. These are passively received by the mind.

Complex ideas are those that are formed by combining simple ideas together. These are actively processed by the mind. Complex ideas are of three types:

1. Ideas of Modes: These are created by combining simple ideas of the same kind, such as the idea of a triangle, which is formed by combining the simple idea of a straight line and the simple idea of a three-sided figure.
2. Ideas of Relation: Such as mother, smaller, similar, different, etc
3. Idea of Substance: Substances are complex ideas that are created by combining simple ideas of different kinds, such as the idea of a chair, which is formed by combining the simple ideas of wood, fabric, and other materials.

What exactly is Locke’s substance?

He defines substance as a “supposed support of qualities”. By this, he means that the qualities we see, feel, or taste in things are not necessarily a part of the thing itself but are rather the way our brain interprets the object based on how it interacts with our senses.

According to Locke, there are two types of qualities of every object; Primary and Secondary.

Primary qualities are objective. For example, a chair is wood, metal, or plastic, and the arrangement of these components gives the chair its shape, size, and structure. They are inherent in the idea of a chair.

Secondary qualities include its color and texture. These are not inherent to the chair itself but are rather qualities that we perceive in the chair. They are not properties of the chair but are instead caused by the chair's primary qualities interacting with our sensory organs — such as the color interacting with our eyes.

The thing that supports both these qualities is what Locke calls substance.

From here, he asks himself what any particular object is made of and he ends up with matter as the final observable primary quality. Then finally, he asks himself, “what is matter made of?”

Locke says that we don't have a clear idea here.

So our idea of substance will always be somewhat confused because we dont know what stands under, supports, or gives rise to observable properties.

So how do you construct knowledge from ideas?

He proposes three grades through which knowledge can be constructed;

1. Intuitive knowledge: This doesn’t require any proof and is immediately evident. It has the highest degree of certainty. For example, the knowledge of the existence of the self. Another example is the idea that “the whole is greater than the sum of its parts.” This principle is also self-evident and requires no further proof or explanation.
2. Demonstrative knowledge: This type of knowledge is acquired through reasoning and demonstration, and it is based on the necessary connections between ideas. Demonstrative knowledge is less certain than intuitive knowledge, but it is still reliable and certain as long as the reasoning is valid. For example, 2 +2 = 4, and that “All Bachelors are unmarried Men”.
3. Sensitive knowledge: Assures the existence of particular objects. For example the color of an object or the touch and feel of an object. But is least certain as it is subject to deceit. Such as a mirage in the desert. While intuitive and demonstrative knowledge is based on clear and distinct ideas, sensitive knowledge is based on our perceptions of the world around us, which can be subjective and subject to error.

Limitations of Knowledge

Locke says that many things are either too big or too small that we cannot clearly perceive them properly. For this reason, knowledge about the physical world is not certain and we must rely on intuition and demonstration.

God, Soul, and Body according to John Locke

1. The body is the material substance, and the matter is the unknown substratum of primary qualities — size, extension, solidity, etc.
2. The soul is the mind. Mind is the substratum of the powers of perceiving, thinking, feeling, and being willing.
3. God is the maker of the external world.

John Locke is deemed to be an inconsistent philosopher

1. By admitting the existence of substance, he goes on the line of the rationalists.
2. The existence of primary and secondary qualities is not empirically justified.
3. He admits the existence of God and Soul
4. He admits to three kinds of knowledge, but as an empiricist, only one kind i.e sensitive knowledge should have been admitted.