Subject affectedness stands as one of the most rigorously theorized concepts in the depth-semantics of voice, receiving its most sustained treatment in Rutger Allan’s 2003 monograph on the Ancient Greek middle voice. For Allan, subject affectedness functions as the abstract semantic invariant underwriting the entire polysemous range of middle-voice usage: wherever a verb’s subject undergoes internal change, absorbs the consequences of an action, or is cognitively and emotionally implicated in an event, the middle voice is the formally marked vehicle for that involvement. The concept is not to be confused with the narrower Greek notion of pathos—sheer passivity—but encompasses a gradient from prototypical passivehood through spontaneous bodily and mental processes to the indirect reflexive, where benefit accrues to the acting subject. Crucially, Allan argues that the active voice is semantically unspecified with respect to subject affectedness, making the middle the marked, informationally dense pole of the opposition. The concept also illuminates scalar phenomena: degrees of affectedness correlate with telicity, punctuality, and the salience of the change undergone. Where active and middle near-synonyms coexist, the middle either foregrounds inherent affectedness already latent in the lexical root or renders it redundant, confirming the theoretical primacy of the feature. The term thus serves as the organizing axis around which questions of transitivity, voice alternation, and event-structure converge.