The greatest light is thrown upon the nature of language by analogy. We have the analogy of the cries of animals, of the songs of birds (“man, like the nightingale, is a singing bird, but is ever binding up thoughts with musical notes”), of music, of children learning to speak, of barbarous nations in which the linguistic instinct is still undecayed, of ourselves learning to think and speak a new language, of the deaf and dumb who have words without sounds, of the various disorders of speech; and we have the after-growth of mythology, which, like language, is an unconscious creation of the human mind. We can observe the social and collective instincts of animals, and may remark how, when domesticated, they have the power of understanding but not of speaking, while on the other hand, some birds which are comparatively devoid of intelligence, make a nearer approach to articulate speech. We may note how in the animals there is a want of that sympathy with one another which appears to be the soul of language. We can compare the use of speech with other mental and bodily operations; for speech too is a kind of gesture, and in the child or savage accompanied with gesture. We may observe that the child learns to speak, as he learns to walk or to eat, by a natural impulse; yet in either case not without a power of imitation which is also natural to him—he is taught to read, but he breaks forth spontaneously in speech. We can trace the impulse to bind together the world in ideas beginning in the first efforts to speak and culminating in philosophy. But there remains an element which cannot be explained, or even adequately described. We can understand how man creates or constructs consciously and by design; and see, if we do not understand, how nature, by a law, calls into being an organised structure. But the intermediate organism which stands between man and nature, which is the work of mind yet unconscious, and in which mind and matter seem to meet, and mind unperceived to herself is really limited by all other minds, is neither understood nor seen by us, and is with reluctance admitted to be a fact.