there is a writter, islamic writer named Dr haqy something who writes in monthly magazine named "almojtama'a" once wrote very interesting research of his between rooh and nafs.
what he saying basically is: rooh as Allah mentioned: mel 3ind Allah. so he uses in that saying: when some one dies we say : roo7uhu tahira intaqalat ela rabia and we dont say it nafsaho taahira.....
After long references from quran ayat and ahadeetj.... he concluded that nafs did bad thing that Allah punished it* by throwing it to earth (story of adam and hawa) so it's not taahira and could do wrong, good and have ability to make decisions that deserves to be punished..etc
in other hand he says: roo7 is not and it's pure and did nothing wrong at all. so when Allah created all human...way before adam... he gathered them in place (some historian, scholares say was mecca now or ka'ba) and when Allah asked : man rabukum they all said : you. and that was roo7 way before creation of human.
Alpha, i always write every time i get those kind of assignments and i always amuse my profs without crossing line
we also have weekly debate class regarding 3ilm algeyb such life after death, before life on earth, how things were in 3arsh with Allah, angels and ibliis. and it's crazy thinking man.