Even if the pleasures of the world are enjoyed as much as their nature permits, if they are as intense, as various and as uninterrupted as possible, yet old age approaches, and with it death. In one word, there is necessarily an end to all those enjoyments and what avails us beyond the moment of enjoyment. It is therefore in the nature of man to look out for an unchangeable, infinite happiness which must come from a being in which there is no change if such a being can be found, it is only from it that man attains an unalterable happiness, and if this be so, this being must become the sole object of all his aspiration and actions. This being is not very far. Human life is a process of knowledge.
All knowledge implies a subject or a knower, whose relation to an object manifests knowledge.
The existence of the knower in an act of knowledge cannot be doubted, for without a knower there is no knowledge, and without knowledge there is no experience. The whole of one s life is constituted of various forms of experience, and all experience is attended with consciousness. Consciousness has always to be in relation with the subject or the knower. Without a knowing self there is no objective knowledge. The experience of a world outside would become impossible if it is not to be given to a knowing subject.