Locke
PRIMARY AND SECONDARY QUALITIES
John Locke believed that every object has primary and secondary qualities. In other words, he maintained that every object consisted of primary and secondary attributes, which are important to develop the final idea of the object. Primary qualities to him were attributes such as shape, seize, movement etc. Of the object, which remains static, regardless of who the perceiver is and how good or bad the circumstances or conditions are. In other words, primary qualities are independent of the perceiver and his way of perceiving the object and they remain the same for every observer. On the other hand secondary qualities were attributes such as color, and those things that we get from the object including the feelings we derive etc.
Primary qualities are thus "Those qualities of an object in the external world which are thought to be characteristic of the object as it is in itself, and thus whether anyone is aware of the object or not. Locke lists extension [an object's occupying space or three-dimensionality, hence its size], shape, motion or rest, solidity or impenetrability, and number as primary qualities of an object. Primary qualities of an object are said to be those, which are measurable. Thus, we can measure...
Secondary qualities are thought to be mind-dependent in that physics does not tell us that the object has a color, but says that it consists of atoms, which lack color. Color is due to matter interacting with minds." (Strayer)
This is not an easy concept to understand because there exist a number of ambiguities in his argument or theory. For one, we cannot say that size, shape and movement are independent of perceiver and can be termed primary qualities. This is because a lot depends on the perceiver in this regard too. For example a person viewing the object from s short distance would get a different idea of its shape and size compared to someone stand far away. Similarly, it is not entirely correct to assume that color of an object is a secondary quality. A thing, which is red in color, would remain red no matter when you see it unless it is something that is prone to changing colors. 'To Locke, primary qualities are utterly inseparable from... [a] body', while secondary qualities 'in truth are nothing…
