This study is a revised version ofa book, published in February 1990 under the same title, as my Ph.D. thesis at the University of Stockholm. Revision of an earlier work poses specific problems, some of which deserve mentioning. After the appearance of the first version of this book new literature on related subjects and a new version of the principal HusserI text involved in the discussion have appeared. The newer literature contains both accounts of Twardowski's thought and its relations to HusserI's philosophy, though without referring to my study from 1990, largely because the texts...