Theodor Lipps

Theodor Lipps (; 28 July 1851 – 17 October 1914) was a German philosopher, known for his theory regarding aesthetics, creating the framework for the concept of Einfühlung (empathy), defined as, "projecting oneself onto the object of perception." This has then led onto opening up a new branch of interdisciplinary research in the overlap between psychology and philosophy.

Biography Lipps was one of the most influential German university professors of his time, attracting many students from other countries. Lipps was very concerned with conceptions of art and the aesthetic, focusing much of his philosophy around such issues. Among his fervent admirers was Sigmund Freud. There were at least two theories that made an impact on Freud's works. The first was Lipps' theory of the unconscious mental events. Lipps was then a main supporter of the idea of the unconscious. The second was Lipps' works on humor. Particularly, Lipps concealed some of the thinker's mysticism, hiding it within the sphere of scientific psychology in his work, Aesthetics of Space and Geometrical Illusions. Lipps developed it into an aesthetic theory, which was refined further by other thinkers such as Roger Fry and Vernon Lee. According to Lipps, empathy incorporates movement or activity, which is bound up with observed object by: 1) being derived from it; and, 2) by being inseparable from it.

Psychologism Lipps was an important adherent of psychologism early in his career. This philosophy was based on the neo-Kantianism that became influential in German philosophy during the second half of the nineteenth century. He became a spokesman of this school as evidenced in his early publications. In his work, Logik (1893), he declared his "unlimited foundational logical psychologism", which is based on a partial identity of psychology of thinking and the logic of thinking. Here, logic is considered the "physics of thinking" rather than an "ethics of thinking". There was also who studied under Lipps at the Ludwig-Maximilians-Universität München and dealt with Husserlian phenomenology in his first publication, Die phänomenale Sphäre.

In the so-called aesthetics of "oughtness", Lipps attempted to reconcile "ought" with "is".

Lipps illusion

The Lipps illusion is a geometric-optical directional illusion discovered by the Lipps. It consists of the fact that parallel lines are no longer perceived as parallel due to inserted kinks. The human perception compensates for kinked lines by perceiving them as approximately straight. The middle sections of the five polygons, each consisting of three segments, are perceived as tilted relative to each other, even though they are parallel. This is caused by the alternating downward and upward orientation of the outer segments. This phenomenon is illustrated in the left part of the diagram. The right side of the illustration clarifies the parallelism of the middle sections.