Accordingly, it is not at all clear that children are, on the whole, any more given to imitation of the mechanical sort, any more suggestible, than adults. They appear so to us chiefly, perhaps, for two reasons. In the first place, we fail to realize the thought, the will, the effort, they expend upon their imitations. They do things that have become mechanical to us, and we assume that they are mechanical to them, though closer observation and reflection would show us the contrary. These actions are largely daring experiments, strenuous syntheses of previously acquired knowledge, comparable in quality to our own most earnest efforts, and not to the thoughtless routine of our lives. We do not see that their echoing of the words they hear is often not a silly repetition, but a difficult and instructive exercise of the vocal apparatus. Children imitate much because they are growing much, and imitation is a principal means of growth. This is true at any age; the more alive and progressive a man is the more actively he is admiring and profiting by his chosen models. A second reason is that adults imitate at longer range, as it were, so that the imitative character of their acts is not so obvious. They come into contact with more sorts of persons, largely unknown to one another, and have access to a greater variety of suggestions in books. Accordingly they present a deceitful appearance of independence simply because we do not see their models. Though we may be likely to exaggerate the difference between children and adults as regards the sway of suggestive influences, there is little danger of our overestimating the importance of these in the life of mankind at large. The common impression among those who have given no special study to the matter appears to be that suggestion has little part in the mature life of a rational being; and though the control of involuntary impulses is recognized in tricks of speech and manner, in fads, fashions, and the like, it is not perceived to touch the more important points of conduct. The fact, however, is that the main current of our thought is made up of impulses absorbed without deliberate choice from the life about us, or else arising from hereditary instinct, or from habit; while the function of higher thought and of will is to organize and apply these impulses. To revert to an illustration already suggested, the voluntary is related to the involuntary very much as the captain of a ship is related to the seamen and subordinate officers. Their work is not altogether of a different sort from his, but is of a lower grade in a mental series. He supplies the higher sort of co-ordination, but the main bulk of the activity is of the mentally lower order.