For the last thirty-four years I have been teaching Psychology by written lectures to students in Ireland and America. From year to year I have been improving my course, and I claim to have advanced with the times. As Uncle Toby's stockings were so often darned that he was not sure whether there remained a single thread of the original fabric, so my prelections have been so constantly mended that I do not know that a single sentence remains of my early lectures. I certainly wish this little work to be used as a textbook, and would thus widen and prolong my teaching power. But people say "dull as a text-book". In physical science and in literature they illuminate their books (as in the old missals) by figures. We cannot do this in mental science, as our thoughts have not forms nor colors. I maintain, however, that they have livelier features. I have sought to avoid dryness by illustrating mental laws by examples taken from human nature. As general laws are drawn from particular cases, so they are best understood by concrete facts coming under our experience. - Summary by Preface