Stealing is wrong. Period. The fact that it's wrong doesn't keep those who steal from stealing, whether it's making personal copies at the office or taking a sample (uninvited) from a chocolate bin.

If something doesn't belong to you, you shouldn't take it. You've assumed the position of ownership when that position wasn't warranted.

If you're bound and determined to take something (anything) that doesn't belong to you, then the least you can do is ask for permission. I have no idea what the chocolate bin owner (or supervisor) would say to your request. I'd expect that most owners or supervisors could care less if you asked permission to make some personal copies from the copier. The most interesting thing, in asking, would be to judge our individual reactions in receiving a refusal. Most people (I'll bet!) are afraid to ask in the first place, and that's the point that those rationalizations come marching in.

I used to be acquainted with a multi-millionaire (honest to goodness) who took a pocketful of paper napkins whenever he went out to lunch. I thought it was wrong and certainly unnecessary given his financial means, but I never said anything since part of my personal ethics is to avoid commenting on negative behaviors of others. I've got enough in this boat of mine to keep me busy correcting myself.