We can only conjecture the life of man, or of his humanizing progenitor, before speech was achieved; but we may suppose that facial expression, inarticulate cries and songs,[23] and a variety of imitative sounds and actions aroused sympathy, permitted the simpler kinds of general ideas to be formed, and were the medium through which tradition and convention had their earliest development. It is probable that artificial gesture language was well organized before speech had made much headway. Even without words life may have been an active and continuous mental whole, not dependent for its unity upon mere heredity, but bound together by some conscious community in the simpler sorts of thought and feeling, and by the transmission and accumulation of these through tradition. There was presumably coöperation and instruction of a crude sort in which was the germ of future institutions. No one who has observed children will have any difficulty in conjecturing the beginnings of speech, since nearly every child starts in to invent a language for himself, and only desists when he finds that there is one all ready-made for him. There are as many natural words (if we may call them so) as there are familiar sounds with definite associations, whether coming from human beings, from animals, or from inanimate nature. These the child instinctively loves to reproduce and communicate, at first in mere sport and sociability, then, as occasion arises, with more definite meaning. This meaning is easily extended by various sorts of association of ideas; the sounds themselves are altered and combined in usage; and thus speech is well begun. Many humble inventors contribute to its growth, every man, possibly, altering the heritage in proportion as he puts his individuality into his speech. Variations of idea are preserved in words or other symbols, and so stored up in a continuing whole, constantly growing in bulk and diversity, which is, as we have seen, nothing less than the outside or sensible embodiment of human thought, in which every particular mind lives and grows, drawing from it the material of its own life, and contributing to it whatever higher product it may make out of that material.