
“Music is a hidden arithmetic exercise of the soul, which does not know that it is counting.”
Musica est exercitium arithmeticae occultum nescientis se numerare animi.
Letter to Christian Goldbach, April 17, 1712.
Arthur Schopenhauer paraphrased this quotation in the first book of Die Welt als Wille und Vorstellung: Musica est exercitium metaphysices occultum nescientis se philosophari animi. (Music is a hidden metaphysical exercise of the soul, which does not know that it is philosophizing.)