This Self is something that exists for itself and not for others. While everything that is purely corporeal only exists for us men, inasmuch as it is perceived, the Self exists by reason of the fact that it perceives. While the _Esse_ of all objects is a percipi, a something perceived, which has come into knowledge, the _Esse_ of the self is a _percipere_, a perceiving, a knowing, that is, the Self can only be thought of as self-knowing. The Self exists even when it does not yet clearly know itself, but it is not the real Self until it knows itself; and it requires long and earnest thought for the Self to know or recognise itself as different from the ego or the body. But if the Self has once come to itself, the darkness or the phenomenal appearance which the Vedânta philosophers called _Avidyâ_ (not knowing, ignorance), or also _Mâyâ_ (appearance, or illusion), vanishes. The origin of this ignorance, this illusion, or the world of appearance, is a question which no human being will ever solve. There are questions which must be set aside as simply _ultra vires_ by every reasonable philosophy. We know that we cannot hear certain tones, cannot see certain colours; why not then understand that we cannot comprehend certain things? The Vedânta philosophers consider the _Avidyâ_ (ignorance) as inexplicable, and this was no doubt originally implied in the name which they gave it. Their aim was, to prove the temporal existence of such an _Avidyâ_, not to discover its origin; and then in the _Vidyâ_, the Vedânta philosophy, to set forth the means by which the Avidyâ could be destroyed. How or when the Self came into this ignorance, _Avidyâ_, or _Mâyâ_ (illusion, or the phenomenal world), the Vedânta philosophers no more sought to explain than we seek to explain how the Self comes into the body, the bodily senses, and the phenomenal world which they perceive. We begin our philosophy with what is given us, that is, with a Self, that in its embodiment knows everything that befalls the body; that for a time is blended with the body, till it attains a true self-knowledge, and then, even in life, or later in death, by liberation from its phenomenal existence, or from the body, again comes to itself.