I have further to explain how far I have received help from other labourers in the same field. The books which I have found of most use are Steinhart and Muller's German Translation of Plato with Introductions; Zeller's 'Philosophie der Griechen,' and 'Platonische Studien;' Susemihl's 'Genetische Entwickelung der Paltonischen Philosophie;' Hermann's 'Geschichte der Platonischen Philosophie;' Bonitz, 'Platonische Studien;' Stallbaum's Notes and Introductions; Professor Campbell's editions of the 'Theaetetus,' the 'Sophist,' and the 'Politicus;' Professor Thompson's 'Phaedrus;' Th. Martin's 'Etudes sur le Timee;' Mr. Poste's edition and translation of the 'Philebus;' the Translation of the 'Republic,' by Messrs. Davies and Vaughan, and the Translation of the 'Gorgias,' by Mr. Cope. I have also derived much assistance from the great work of Mr. Grote, which contains excellent analyses of the Dialogues, and is rich in original thoughts and observations. I agree with him in rejecting as futile the attempt of Schleiermacher and others to arrange the Dialogues of Plato into a harmonious whole. Any such arrangement appears to me not only to be unsupported by evidence, but to involve an anachronism in the history of philosophy. There is a common spirit in the writings of Plato, but not a unity of design in the whole, nor perhaps a perfect unity in any single Dialogue. The hypothesis of a general plan which is worked out in the successive Dialogues is an after-thought of the critics who have attributed a system to writings belonging to an age when system had not as yet taken possession of philosophy. If Mr. Grote should do me the honour to read any portion of this work he will probably remark that I have endeavoured to approach Plato from a point of view which is opposed to his own. The aim of the Introductions in these volumes has been to represent Plato as the father of Idealism, who is not to be measured by the standard of utilitarianism or any other modern philosophical system. He is the poet or maker of ideas, satisfying the wants of his own age, providing the instruments of thought for future generations. He is no dreamer, but a great philosophical genius struggling with the unequal conditions of light and knowledge under which he is living. He may be illustrated by the writings of moderns, but he must be interpreted by his own, and by his place in the history of philosophy. We are not concerned to determine what is the residuum of truth which remains for ourselves. His truth may not be our truth, and nevertheless may have an extraordinary value and interest for us.