This is a translation of Edmund HusserI's lecture course from the Summer semester 1907 at the University of Gottingen. The German original was pub- lished posthumously in 1973 as Volume XVI of Husserliana, Husserl's opera omnia. The translation is complete, including both the main text and the supplementary texts (as Husserliana volumes are usually organized), except for the critical apparatus which provides variant readings. The announced title of...