CONSCIOUS.—Here we come to something specially distinctive of higher animal life. Probably it makes its incipient appearance low down in the scale, in vague feelings of pain or discomfort, and of pleasure; though it is not likely that worms are as conscious as they appear to us to be. In its higher grades consciousness means awareness of the world and of ourselves, a discrimination between the self and the external world—“self-consciousness” in its proper signification: an immense subject that can only be hinted at to children. They can, however, be taught to have some appreciation of the senses, or channels, whereby our experience of external nature is gained; and to perceive that the way in which we apprehend the universe is closely conditioned by the particular sense-organs which in the struggle for existence have been evolved by all the higher kinds of animal life,—organs which we men are now beginning to put to the unfamiliar and novel use of scientific investigation and cosmic interpretation. What wonder if we make mistakes, and are narrow and limited in our outlook! _Digression on the Senses_ Our fundamental interpretative sense is that of touch—the muscular sense generally. Through it we become aware of space, of time, and of matter. The experience of _space_ arises from free motion, especially locomotion; _speed_ is a direct sensation; and _time_ is the other factor of speed. Time is measured by any uniformly moving body—that is by space and speed together. Muscular action impeded, the sense of _force_ or resistance, is another primary sensation; and by inference from this arises our notion of “matter,” which is sometimes spoken of as a permanent possibility of sensation. Hardness and softness, roughness and smoothness, are all inferences from varieties of touch. Another sense allied to touch is that of _temperature_, whereby we obtain primitive ideas concerning heat. Then there are the chemical senses of taste and smell; and lastly, the two senses which enable us to draw inferences respecting things at a distance. These two attract special attention; for the information which they convey, though less fundamental than that given by the muscular sense, is of the highest interest and enjoyment. The ear is an instrument for the appreciation of aerial vibrations, or ripples in the air. They may give us a sense of harmony; and in any case they enable us to infer something concerning the vibrating source which generated them, so that we can utilise them, by a prearranged code, for purposes of intelligent communication with each other—a process of the utmost importance, to which we have grown so accustomed that its wonder is masked.