An etymology long current among Indo-Europeanists runs as follows: Gk. “ the dark underworld ” ( “ dark, gloomy ”, “ black, dark ”), Goth, riqis “ darkness ” (riqizyan “ to become dark ”, riqizeins “dark”) Arm. erek “evening”, Skt. rajas “darkness, dimness; dark space, space; dark mist, mist, cloud, atmosphere; dust, dirt; pollen; arable land (as black); the darkening quality, passion, emotion; the second of the three gunas whose nature is active, urgent, and variable ”. As far as the first three languages are concerned the equation is simple and straightforward; but the Sanskrit word creates difficulty on account of the extreme variety of meanings which it is said to possess, and the semantic problems which this involves.