"The radical error of those who believe that we perceive things _as they are_, consists in mistaking a metaphor for a fact, and believing that the mind is a mirror in which external objects are reflected. But, as Bacon finely says, 'The human understanding is like an _unequal mirror_ to the rays of things, which, _mixing its own nature with the nature of things, distorts and perverts them_.' We attribute heat to fire, and color to the flower, heat and color being states of our consciousness, occasioned by the fire and the flower under certain conditions. Perception is nothing more than a _state of the percipient_, a state of consciousness.... Of every change in our sensation we are conscious, and in time we learn to give definite names and forms to the causes of these changes. But in the fact of consciousness there is nothing _beyond_ consciousness. In our perceptions we are conscious only of the changes which have taken place within us.... All we can do is to identify certain _external appearances_ with certain internal changes.... We conclude, therefore, that the world _per se_ in nowise resembles the world as it appears to us. Perception is an Effect; and its truth is not the truth of _resemblance_, but of _relation_.... Light, color, sound, taste, are all states of Consciousness; what they are beyond consciousness ... we cannot know, we cannot imagine, because we can only conceive them _as_ we know them. Light, with its myriad forms and colors--Sound, with its thousand-fold life--make Nature what Nature appears to us. But they do not exist, _as such_, apart from our consciousness; they are investitures with which we clothe the world. Nature, in her insentient solitude is an eternal Darkness--an eternal Silence." CHAPTER XII. FURTHER ANALYSIS OF THE UNIVERSE. In a previous chapter, some special reference has been made to a little German professor named Immanuel Kant. He was born at Königsberg, in 1724. In 1781 he wrote a book which he called "The Critique of Pure Reason." This provokingly modest title, as already said, covered, in reality, _the analysis of mind and matter, time and space_. It was the most far-reaching piece of purely intellectual work that had ever been given to the world. It has split the heads of hundreds of "philosophers." Certain thinkers have fancied they have thought beyond it, and have supposed it to be laid on the shelf of "deceased philosophy." Meanwhile, we are told, the universities "are returning to the study of Kant." Better still, some of them are even beginning to understand him. Here we shall take him straight, paying no attention to any of the side issues in which he was apt to cover himself up.[56]