John Locke is the founder of a new school of philosophy called empiricism. He did it through a new interpretation of how we get knowledge. The key concept of his empiricism is that everything we know we know from experience. It was diametrically opposite to the Cartesian view that we have our mind stuffed with ideas during our birth.
Builder of a new system
Locke built a new system of philosophy. In order to build his new system Locke, at first, aims to clear the ground a little and remove some of the rubbish that lies in the way to knowledge.The main rubbish that he removes is the rubbish of the innate idea. Side by side Locke also describes how our mind works and how much knowledge we can expect from our mind.
Start of empiricism
With the publication of his celebrated work An Essay Concerning Human Understanding, Locke founded empiricism in Britain.According to Locke our knowledge is restricted to ideas generated by objects we experience. And ideas take two forms sensation and reflection. Without exception all our ideas come through our senses and through reflection upon these ideas our mind becomes internally aware of these ideas.
First of all we have to have the idea of sensation and then that of reflection, because reflection means simply mind’s taking notice of its own operations upon ideas, given through senses. Reflection involves perception, thinking, doubting, believing, reasoning, knowing, willing etc.Locke insists that each person’s mind is in the beginning like a blank sheet of paper, void of all characters and the senses are the only agents to provide the mind with ideas.
Simple and complex ideas
Locke divides ideas into two groups namely simple and complex ideas. The source of ideas is experience. There are two kinds of experiences namely internal and external. On the basis of these experiences our ideas are also of two kinds: simple and complex ideas.
Simple means single idea. Whenever we look at an object ideas come into our mind single file. Although an object has several ideas blended together, the mind receives the ideas of those qualities separately such as a white lily has the qualities of whiteness and sweetness without any separation, but our mind can think of them separately, because each idea enters through a different sense, namely the sense of sight and that of smell. But different ideas may enter into our mind through the same sense, such as both the ideas of hardness and coldness enter through the same sense namely the sense of smell. Simple ideas constitute the chief source of the raw materials out of which our knowledge is made. Simple ideas are received passively by our mind through our senses. Simple ideas at first originate in sensation and then by mind’s taking notice of its own operation originate in reflection.
Complex ideas occur when our mind puts together several simple ideas and makes a composite idea out of simple ideas. Unlike simple ideas, complex ideas are not received passively by our mind. Here the mind actively receives the ideas. The mind does the three things such as the mind joins ideas, brings them together, but holds them separate and abstracts. Thus the mind joins the ideas of whiteness, hardness, and sweetness to form the complex idea of a lump of sugar.
Primary and secondary qualities
To describe even more detail how we get our ideas Locke turned his attention to the problem of how ideas are related to the objects that produce them. In order to account for how we get our ideas, Locke says that objects have qualities and he defines a quality as the power to produce idea into our mind. Locke distinguishes between two kinds of qualities namely primary and secondary qualities.
Primary qualities are those qualities that really do exist in the bodies themselves. Primary qualities resemble exactly those qualities that inseparably belong to the object. A snowball, for example, looks round and is round, appears to be moving and is moving.These qualities are primary because they really exist in the object snowball. Primary qualities refer to solidity, motion, or number.
Secondary qualities are those qualities that have no exact counterpart in an object. We have the idea of cold when we touch the snowball and the idea of white when we see it, but there is no whiteness or coldness in it. Secondary qualities such as colors, tastes, sounds, odors, warmth, and smells do not belong to or constitute bodies except as powers to produce these ideas in us. What Locke wanted by this distinction is to distinguish between appearance and reality.
The discussion of substance is an important part of Locke’s theory of knowledge. He approached the problems from common sense point of view. According to him as there are qualities so there must be something that holds these qualities. If ,for example, we ask what has shape and color ,we answer something solid and extended. Solidity and extension are the primary qualities and if we ask in what they subsist, Locke answers substance. In Locke’s philosophy substance is an abstract idea and he himself could not give satisfactory definition of substance.
The degrees of knowledge
The extension and validity of our idea depend upon the relations our ideas have to each other. Locke defines knowledge as nothing more than the perception of the connection of an agreement or disagreement or repugnancy of any of our ideas. There are three modes of perception namely intuitive, demonstrative and sensitive and each one leads us to a different degree of knowledge regarding reality.
Intuitive knowledge is the most fundamental and certain. It leaves no room for doubt, hesitation and examination. The mind perceives the agreement and disagreement of two ideas immediately by themselves without the intervention of any other idea. We know that a circle is not a square or that 6 is not 8, because we can perceive the repugnancy of these ideas to each other. From intuitive knowledge we know that we exit. Experience convinces us that we have intuitive knowledge of our own existence.
Demonstrative knowledge occurs when our minds perceive agreement and disagreement of ideas, not immediately, but through other mediating ideas. We reach this knowledge through investigation, reasoning, questioning and inquiry. Each step in demonstration rests upon intuitive certainty. This type of knowledge leads our mind to an exiting reality. By an intuitive certainty, man knows that out of nothing nothing can be created. Since there are in fact existing things around us that begin and perish in time, it is an evident demonstration that from eternity there has been something. And Locke terms this eternal being which is most knowing and most powerful as God.
Sensitive knowledge is not knowledge in the strict sense of the term. It only passes under the name of knowledge. So this sort of knowledge does not give us certainty, nor does it extend very far. We have the knowledge of the existence of a particular man as long as we observe him. But whenever the man moves away from us, we are no longer assure of his existence. Nevertheless, sensitive knowledge gives us some degree of knowledge but not certainty.
Thus, Locke founded empiricism in Britain. Later his followers Berkeley and Hume led empiricism to further development.