The Idea of Infinity, which we shall refer to in a later View and show to be a false conception, is therefore a necessary result of the limitation of our thoughts; our physical Ego cannot conceive beyond the Finite as long as we are conscious of living under present conditions. With every act of perception by our senses, we have therefore not only intuition of the Visible or Finite, but we become at the same moment aware of an Invisible Infinite beyond. Time appears to us as an inconceivable, intangible something, which gives us the impression of movement without anything that moves it. Space is an omnipresent, intangible, inconceivable nothing, outside of which nothing which has existence can be even thought to exist. Let us now try and get an insight into what we mean by perception of distance in space. The appreciation of distance depends upon what is called _parallax_, or the apparent displacement of projectment of an object when seen by our two eyes separately. If you hold up a finger and look at it, with each eye separately, you will see that the finger is projected by each eye on to a different part of the background; the angle which the lines of sight, from each eye, make when they meet at the object, is called the angle of parallax, and the further the object is away the smaller that angle becomes; it is, in fact, the angle subtended, at the object, by the distance between the two eyes. As the object is brought nearer the eyes have to be inclined inwards to impinge on that object; the appreciation of distance then, in our sense of sight, is dependent upon our perception of the amount of inclination of those two lines of sight, and is therefore an acquired knowledge. The distance between the eyes is about 2-1/2 inches, and this is a very short base line upon which to estimate distance; in fact, without the help of perspective and known dimensions of surrounding objects, it is doubtful if anyone could by its means estimate distance beyond a few hundred yards. The object would, of course, also have to be an unknown one, as, otherwise, the converse of the above comes into play, and the distance could be estimated by the angle which the known diameter of the object subtends at the eye; but this necessitates the size of the object being known beforehand and the employment of perspective.