Like everything else, it depends on a number of variables. If I have tight players behind me and I've developed a tight image, then I will consider raising with 33 in middle position. Even if there are a lot of high cards on the flop, I can still c-bet and represent a big pair. There are other important factors to consider, like (1) any limpers in front of me ? (2) stack sizes, (2) tournament or cash game.