Wolfgang Hagen is not the best known of German media theorists outside of Germany - despite his long career, and such huge books as on the history of radio. Hagen's way of thinking through media epistemologies - and hence related to media archaeologies - is however important in the way it ties into that concept material and phantasmatic dimensions of epistemological objects (instead of the slightly always more vague "episteme" of Foucault).
With a keen interest in the 19th century, Hagen is able to tap into the formative technicality of media cultures - and hence the prehistory of the contemporary "software unconscious". As such, this quote by Hermann von Helmholtz, requoted from Hagen (and his translation) is a good example of the German focus on Helmholtz as important figure as for instance Freud in thinking about the medial unconscious of our culture - and aesthetics. A lot of this you recognize from emphases of Kittler ("psychophysics" as the way to understand the emergence of the So-Called-Man of media cultures), but here in the own words of Helmholtz:
"Aesthetics seeks the essence of the artistically beautiful in its unconscious rationality. I have... sought to reveal the hidden law that determines the mellifluousness of harmonic tonal connections. Actually, this is something that happens unconsciously as far as the overtones are concerned, which are indeed perceived by the nerves but do not usually come forth into the domain of conscious ideation; nevertheless, their pleasantness or unpleasantness is felt without the listener knowing where the grounds for such feelings lie." (Helmholtz,Über die physiologischen Ursachen der musikalischen Harmonie, lecture from 1857, published in Vorträge und Reden in 1896 90).
Hagen's article - from which this quote comes from - is in the book Artists as Inventors, Inventors as Artists.
What's more, this quote points to the early formulations and scientific basis that relates to economies and politics of affect - such a crucial part of societies of spectacle and post-Fordism.