The achievement of speech is commonly and properly regarded as the distinctive trait of man, as the gate by which he emerged from his pre-human state. It means that, like Helen Keller, he has learned that everything has, or may have, a name, and so has entered upon a life of conscious fellowship in thought. It not only permitted the rise of a more rational and human kind of thinking and feeling, but was also the basis of the earliest definite institutions. A wider and fuller unity of thought took place in every group where it appeared. Ideas regarding the chief interests of primitive life—hunting, warfare, marriage, feasting and the like—were defined, communicated and extended. Public opinion no doubt began to arise within the tribe, and crystallized into current sayings which served as rules of thought and conduct; the festal chants, if they existed before, became articulate and historical. And when any thought of special value was achieved in the group, it did not perish, but was handed on by tradition and made the basis of new gains. In this way primitive wisdom and rule were perpetuated, enlarged and improved until, in connection with ceremonial and other symbols, they became such institutions, of government, marriage, religion and property as are found in every savage tribe. Nor must we forget that this state of things reacted upon the natural capacities of man, perhaps by the direct inheritance of acquired social habits and aptitudes, certainly by the survival of those who, having these, were more fitted than others to thrive in a social life. In this way man, if he was human when speech began to be used, rapidly became more so, and went on accumulating a social heritage. So the study of speech reveals a truth which we may also reach in many other ways, namely, that the growth of the individual mind is not a separate growth, but rather a differentiation within the general mind. Our personal life, so far as we can make out, has its sources partly in congenital tendency, and partly in the stream of communication, both of which flow from the corporate life of the race. The individual has no better ground for thinking of himself as separate from humanity than he has for thinking of the self he is to-day as separate from the self he was yesterday; the continuity being no more certain in the one case than in the other. If it be said that he is separate because he feels separate, it may be answered that to the infant each moment is separate, and that we know our personal life to be a whole only through the growth of thought and memory. In the same way the sense of a larger or social wholeness is perhaps merely a question of our growing into more vivid and intelligent consciousness of a unity which is already clear enough to reflective observation.