It is an acknowledged fact that we perceive errors in the work of others more readily than in our own. —Leonardo da Vinci In this Beginner's Psychology I have tried to write, as nearly as might be, the kind of book that I should have found useful when I was beginning my own study of psychology. That was nearly thirty years ago; and I read Bain, and the Mills, and Spencer, and Rabier, and as much of Wundt as a struggling acquaintance with German would allow. Curiously enough, it was a paragraph in James Mill, most unpsychological of psychologists, that set me on the introspective track,—though many years had to pass before I properly understood what had put him off it. A book like this would have saved me a great deal of labour and vexation of spirit. Nowadays, of course, there are many introductions to psychology, and the beginner has a whole library of text-books to choose from. Still, they are of varying merit; and, what is perhaps more important, their temperamental appeal is diverse. I do not find it easy to relate this new book to the older Primer,—which will not be further revised. There is change all through; every paragraph has been rewritten.