To this insight into the underivability and pre-eminence of consciousness over the world of external reality there must be added at this stage a recognition of its peculiar creative character. We have here to recognise that consciousness itself creates its world,—that is, the world that becomes our own through actual experience, possession, and enjoyment. We are led to this position even by the conception now current in natural science of the world as it is, not as it is mirrored in consciousness, and the theory of the “subjectivity of sensory qualities.” The qualities which we perceive in things through the senses are “subjective”; philosophy has long taught that, and now natural science teaches it too. That is to say, these qualities are not actually present in the things themselves; they are rather the particular responses which our consciousness makes to stimuli. Take, for instance, tone or colour. What we call tone or sound is not known to acoustics. That takes cognisance only of vibrations and the conditions of vibration in elastic bodies, which, by means of the ear and the nerves of hearing, become a stimulus of consciousness. Consciousness “responds” to this stimulus by receiving a sense-impression of hearing. But in this, obviously, there is nothing of the nature of oscillations and vibrations, but something quite different. What outside of us is nothing more than a complex process of movement according to mathematical conditions, blossoms within us to a world of sound, tone, and music. The world itself is soundless, toneless. And the same is true of light and colour; “light” and “blue” are nothing in themselves—are not properties of things themselves. They are only the infinitely rapid movements of an infinitely delicate substance, the ether. But when these meet our consciousness, they spin themselves within us into this world of light and colour, of brilliance and beauty. Thus without us there is a world of a purely mathematical nature, without quality, charm, or value. But the world we know, the world of sound, light, and colour, of all properties whatsoever, of the ugly or the beautiful, of pain and pleasure, is in the most real sense the product of consciousness itself, a creation which, incited by something outside of itself and of a totally different nature, which we can hardly call “world,” evolves out of itself and causes to blossom. No part of this creation is given from without; not the blue of the heavens, for outside of us there is no colour, only vibrations of the ether; not the gold of the sun nor the red glory of the evening sky. External nature is nothing more than the stimulus, the pressure upon the mind, which liberates from its depths the peculiar reactions and responses to this stimulus, and calls them forth from its own treasure-stores. Certainly in this creating the consciousness is entirely dependent on the impressions stamped on it from outside, and to that extent upon