Yes you can. But while under Dark Arts (using your example) you'd want to skill up on monsters that are above the Dark Arts skill level so above 246 instead of above 191. I took my Dark Skill from 101 to 210 off Qiqirn ranger mobs this way.
It should be noted, as a Scholar you will actually see a reduced benefit from Light/Dark arts until you are capped for your SCH. This needs to be mentioned, because a lot of players still assume that Light/Dark arts raises your skill to the B cap, when it's not always the case.