Most of the volumes of this series are occupied with large subjects and subjects commonly recognized as important to great masses of people at the present day. In devoting the present volume to the study of a single writer, remote from us in time and civilization and scarcely known by more than name to many readers of the Library, I am moved by the belief that, quite apart from his disputed greatness as a poet and thinker, apart from his amazing and perhaps unparalleled success as a practical playwright, Euripides is a figure of high significance in the history of humanity and of special interest to our own generation.