Locke. Locke also advocates that the nature of the senses can be divided into "primary nature" and "secondary nature". Locke thinks that the world is made of matter. The main properties of matter include those that are inseparable from matter, such as shape, motion or stillness, quantity, etc. Secondary attributes include other attributes, such as color, sound and smell. Locke thinks that the first sex is in the object and the second sex is only in the perceiver.