Why shouldn't you cheat?
You're not well-prepared for the quiz or test. You have heard people say it's wrong to cheat, but you really need to do decently on this, and it's just too bad, but you gotta do what you gotta do. And after all, everyone does it from time to time. And it's only a quiz, not like you murdered someone. It's not really that bad. So, you're starting to rationalize cheating.
You're wrong. Here's why.
Simple reasons first: 1) high probability, higher than you think, that you'll get caught, and the penalty for getting caught is much worse than what happens if you get a poor grade: you'll get kicked out of the class, receive an F as a final grade, and the professor will recommend to the Dean that you be expelled. 2) low probability, lower than you think, that the person you're cheating off is vastly smarter than you are. Do you really regard yourself as the stupidest person in the room, yet also the luckiest, in that you're next to or behind the smartest? Don't bet on it.
But say you think you can get away with it, and you're pretty sure the other person is pretty much on the ball. It's still a bad idea.
You think you're slightly bending the rules to advance your self-interest. But the truth is, you are not advancing your self-interest by cheating. Think for a second - how do you see yourself? What kind of person are you? You think of yourself as a basically decent person, right? Let's check on that. To cheat is both to steal and to lie. Why? It's stealing because you are taking something from someone without permission. It's also stealing in the sense that you are claiming title to something (a grade) you have not earned. That's theft. And by passing it off as your own work, you are lying. You are making a representation that you have done work you have not in fact done. That's lying. So when you cheat, you are stealing and lying. That's despicable. Are you a despicable person? Is that the self-image you would like to have? You can pretend that it's not that bad, but you'll be lying again, this time to yourself, and you won't be able to fool yourself like that for too long. Be honest with yourself: is it of no importance to you to have personal integrity? Is honor something you really don't care about at all? You probably do not want to be a horrible person, or to think of yourself as a horrible person. So don't do things that are despicable like lying and stealing. Bombing the quiz may sting a little, but that's nothing compared to how you'll feel when you realize that you're a dishonorable and morally worthless person. And that's what you'll be if you cheat. So don't do it.