Oswald Külpe’s books and published works cover a variety of subject matter, which impacted his interest in psychology. Examples of his publication topics include logic, aesthetics, philosophy, and epistemology. His first major book, published in 1893, was "Grundriss der Psychologie". The handbook summarized a comprehensive amount of experimental research at the time, including new research on reaction time, contributions to psychophysics, Carl Stumpf’s research into tonal fusions, and Hermann Ebbinghaus’ research on memory. He defined psychology as, “the facts of experience," as the book concerned itself strictly with scientific fact. The lack of focus on the concept of thought in his book is interesting because the Würzburg school greatly researched mental set and imageless thought. He once wrote to a colleague, however, that the concepts behind the book were, “the source of the investigations in the psychology of thinking.” So, he had anticipated the idea of imageless thought in this publication. Külpe was still under the shadow of Wundt during this time. In fact, only one of his distinctive views was included, which was his criticism of the subtractive procedure on reaction time. Two years later, Grundriss der Psychologie was translated into English by Edward Titchener under the title Outlines of Psychology.