 Prior to Ebbinghaus, most contributions to the study of memory were undertaken by philosophers and centered on observational description and speculation.For example, Immanuel Kant used pure description to discuss recognition and its components and Sir Francis Bacon claimed that the simple observation of the rote recollection of a previously learned list was "no use to the art" of memory.This dichotomy between descriptive and experimental study of memory would resonate later in Ebbinghaus's life, particularly in his public argument with former colleague Wilhelm Dilthey.