In the sad years that have intervened since this book was published, we have all been impressed by the brilliant achievements of science in every department of practical life. But whereas the application of chemistry and electricity and biology might, perhaps, be safely left to the specialists, it seems to me that in a democracy it is essential for every single person to have a practical understanding of the workings of his own mind, and of his neighbor's.

The understanding of human nature should not be left entirely in the hands of the specialists, it concerns all of us. There is no better way for beginning the study of human nature than by following the unfolding of a spirit as it takes place before us in the growth of a child.

I am humbly grateful of the assurances received from many quarters that these chapters have aided many parents and teachers in such study. In the present edition I have made a number of slight changes to harmonize the reading with the results of later scientific studies; there is a new list of references and some new material in the chapter on sex education; and there is a new chapter suggesting the connection between the new psychology and the democratic ideals of human relations.

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