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. In 1895, Külpe published a handbook called
Einleitung in die Philosophie (which translates to
Introduction to Philosophy). This book was a guide to both past and present philosophy at the time, and a basic text for German university students of not just general philosophy, but psychology, logic, ethics, and aesthetics as well. In the book, Külpe also looks at the relations of the body and the mind, and in doing so, takes a dualistic position. Külpe also gives a clear description of the relationship between physical and psychical, or in other words, natural science and psychology. He identifies the possibility of what he refers to as a mind substance. He theorized that both matter and mind are abstractions from thought experience. He believed that if matter required the idea of substance, why would the mind not require substance as well? The book is less than 350 pages and went through seven editions and four translations, including into English by W. B. Pillsbury and Titchener under the title
Introduction to Philosophy. In 1912, Külpe published
Über die moderne Psychologie des Denkens, which translates into English as
On the Modern Psychology of Thinking. In this book, he was looking back on his focus on the systematic experimental introspection method. He believed that before systematic experimental introspection existed, research on thought was incomplete. He also believed that having the subject report only on sensations, feelings, and presentations in thought research was severely limiting in that it did not provide an acceptable opportunity to identify what could be considered neither sensation, feeling, nor presentation. Once they were given the opportunity to objectively self-observe and describe what was neither sensation, feeling, nor presentation, yet was still a thought process, Külpe and his colleagues identified the need for new definitions and concepts aside from those that already exist. As Külpe wrote: “The subjects began to speak in the language of life and assign less importance to the presentations for their inner world. They knew and thought, they judged and understood, they grasped the meaning and saw connections without receiving any real help from occasionally occurring imagery.”
Die Realisierung, a three-volume text composed of Külpe's lectures, was published from 1912 through 1923. Other notable publications include the publication of a
monograph,
Zur Katagorienlehre, which was presented in the year of his untimely death, 1915, before the Bavarian Academy of Science. Other books by Külpe include the 1912 publication of
Psychologie und Medizin and
Philosophie der Gegenwart. ==References==