There is, however, a still graver and quite insuperable distinction between the parallactic path and the aberrational path.
aberration 1590s, "a wandering, straying," from L. aberrationem (nom. aberratio) "a wandering," from pp. stem of aberrare "go astray," from ab- "away" + errare "to wander" (see err). Meaning "deviation from the normal type" first attested 1846.