Philosopher Locke thinks, sense experience is the only way to the knowledge. At childhood our mind is a blank white paper (Tabula Rasa). Each and every idea comes into mind (to the ration) through sense organ while our mind is inactive. These ideas get into the mind through two ways a) sensation, b) reflection. Through sensation we get the ideas of coldness, hotness etc. And through reflection we can get the ideas of happiness, sorrows, faith etc.. “Sensation is feeling, this feeling converted to idea when it gets into the mind through sense organ.” After ideas have reached to the mind, our mind becomes active and tries to make relation among them with the similarities and dissimilarities of those ideas. This relation is called knowledge and ideas are the basic materials of knowledge.Locke has devided the ideas into two- a) simple ideas b) complex ideas. Simple idea is of four types–1)ideas of one sense organ, such as– ideas of colours 2)ideas of more than one sense,such as- idea of motion, extension 3)ideas of reflection, such as- idea of faith, doubt 4)ideas of sensation and reflection both, such as – unity, energy, happiness etc. Complex idea is of three types a)mode, b)substance and c)relation.Mode: Mode is of two types i)unmixed modes, such as- twenty, we can get the idea of twenty by repeatation of the same number one, ii)mixed mode, such as-beauty.Substance:No ideas can exist without a substrate or shelter, this shelter or substratum is called the substance.Relation:Comparing together the two ideas we can get the idea of relation, such as- causal relation. “The power to generate feeling about any object is called quality”, Locke says. A ice-handball in our mind produces the ideas of whiteness, coldness, and roundness. This powerof the ice-handballto produce the feelings (sensation) of coldness, whiteness is called quality and these feelings get into our mind (to the ration) are called ideas. Quality is of two types a)primary(objective) and b)secondary(subjective).However, we know only the ideas through the mind but not the worldly objects, which come contact to our senses.Mind knows the ideas, ideas know the object but mind and object could not come to contact.