What is all this but a kind of play upon words? We are so constituted that the impressions which a thing external to us produces upon our nerves of perception are instantly transmitted to the brain, and the mind has an instantaneous perception of that object. The phenomenon which we see with our eyes, or become sensible of by touch, thus becomes a thing perceived by the mind, and when we think of it we do not think of its ghost, but we think of the thing itself. Did Laura Bridgman, who had neither eye-sight nor hearing nor speech, but who acquired all her ideas of external objects by the sense of touch, conceive of a round or a square, a rough or a smooth surface, by contemplating the ghost or double of what she touched? And had she no thinking in the true sense of thinking, because the double, or _imago_ of the thing which she touched--the so-called _noumenon_--was at once necessary to her mental perception, and yet could not be thought of without seeing the object by the corporeal eye? She had no corporeal eye in which there was any vision. All her mental perceptions of external objects were acquired by the sense of touch alone; and we may well believe that she did not need the supposed _noumenon_ to give her an idea of _phenomenon_. She perceived many phenomena by the simple transmission to her brain, along her nerves of touch, of the impressions produced upon them by external objects; and there is every reason to believe that many of her perceptions were as accurate and true as those which we derive from all our senses. We may now dismiss Mr. Spencer's distinction between _phenomenon_ and _noumenon_ as a distinction quite needless for the elucidation of what takes place in thinking of that which is behind appearance, and may proceed with the discussion of what remains of the passage above quoted. At the risk of wearying by repetition, I will again resort to the illustration before employed, and will again describe how we reach the conception, for example, of endless space. According to Mr. Spencer, space, or extension, as a thinkable idea, or a subject of thought, is confined to a measurable extent of space. This is the phenomenon, or appearance. All our forms of thought are, it is said, molded on our experience of phenomena that are measurable, or capable of being definitely described; and the connotations of our words which express the relations of phenomena relate to phenomena that we measure, or see, and can definitely describe. Therefore, we can not think of a reality that is behind appearance; can not bring the consciousness of such a reality into any shape, nor bring into any shape its connection with appearance.