One hundred years ago - in 1899 - Emil Kraepelin, Professor of Psychiatry in Heidelberg and later in Munich - created, in two very important pieces of work, the concept of "manisch-depressives Irresein" ("manic-depressive insanity"). The first was entitled Die klinische Stellung der Melancholie(The Clinical Position of Melancholia), and the second publication was the sixth edition of his textbook. In the same year Kraepelin's pupil and colleague, Wilhelm Weygandt, published his book Uber die Mischzustande des Manisch- Depressiven Irreseins (On the Mixed States of Manic-Depressive Insanity). A...

One hundred years ago in 1899 Emil Kraepelin, Professor of Psychiatry in Heidelberg and later in Munich created, in two very important pieces of work, the concept of "manisch-depressives Irresein" ("manic-depressive insanity"). The first was entitled Die klinische Stellung der Melancholie(The Clinical Position of Melancholia), and the second publication was the sixth edition of his textbook. In the same year Kraepelin's pupil and colleague, Wilhelm Weygandt, published his book Uber die Mischzustande des Manisch- Depressiven Irreseins (On the Mixed States of Manic-Depressive Insanity). A...

This study appears at a time when a decisive turn is due in the research on personality development. After many years of stagna tion and misguided research in this field, this book should lead to a thorough revision and a better understanding of current views on the factors which have an influence on personality. Let us consider the unsatisfactory aspects of the recent develop ments in personality studies. At the beginning of this century, the revolutionary insight gained ground that personality is susceptible to various influences, in particular to those resulting from human interaction....