No harm comes to man from outside alone: dumbness is the objective spirit.

The first clause echoes a broadly Stoic-sounding claim—harm is not merely inflicted from without—but Adorno’s twist is characteristically negative: what destroys us is mediated through social and subjective forms (habituation, conformity, damaged experience) rather than arriving as a simple external blow. The second clause, “dumbness is the objective spirit,” suggests that what presents itself as “objective” (institutions, prevailing rationality, public language) can congeal into mute, unreflective force: a spirit that no longer speaks truth but enforces silence and incapacity to think. Read together, the line indicts a society in which external domination becomes internalized, and where objectivity itself can become a vehicle of stupefaction.