Narziß Ach first studied medicine in Würzburg. He then worked as a ship's doctor on voyages to East Asia. Afterwards he worked for the psychiatrist Kraepelin in Heidelberg.
Attracted by Oswald Külpe, Ach decided to study philosophy in Würzburg in 1898. Already in 1899 he received his doctorate under Külpe and became his assistant for one year.

Along with Marbe, Ach also conducted studies using the method of systematic experimental introspection with a focus on volition. He discovered the determinining tendencies directing our attention, thinking and decisions in the context of specific actions. Moreover, Ach was not only a psychologist and medicine, but also a very talented and versatile inventor, to whom, among other things, a forerunner of the tachograph and at least improvements to the gyrocompass can be traced. For psychology, he developed also the card changer shown here in a 3D animation.
The photo shows Ach in 1892 during the time when he studied Medicine and Philosophy at Würzburg University.