"Welcome to economics 101. By the end of this semester I hope to indoctrinate you into the cult of economics, just like my teachers indoctrinated me. But first, we must define economics.
In order to do that, you need to know some of the jargon of the trade. Does everyone know what it is to be selfish? Economics starts out recognizing that people always act for their own gains - and there is nothing wrong with that ever. Oh wait, I see a hand... what's that?... you say what about seemingly unselfish behavior and what about acts toward a common good? No No No, see I just told you economics shows us that people don't really care or need to worry about these things. See look, I'll prove it (writes a utility function on the board). See? This math equation says so. Ahem, ok, moving on....
Second, economics recognizes that there are scarce resources, and that the best way to allocate these resources is to let selfish people trade them in a market. These markets always function perfectly and in doing so, create the most efficient system possible.
That brings us to our second term: 'efficiency'. You see class, 'efficiency' is a necessary result of the indoctrination I'm teaching you today. Because selfish people are allowed to own property, and because they are allowed to freely trade in a market, society's gains are maximized. Imagine one of these markets was baking pies. Efficiency is basically giving society as much of that pie as possible.
Yes? You have another question... what's that you say? What about if you are a person that wants a piece of pie and can't afford it? No No No. You aren't understanding right. Economics doesn't have anything to say about equity or fairness or things that Europeans care about, economics talks about important things, like making sure we don't just have a blueberry pie, we have blueberry pie with lots of whipped cream. That's what's important here. See, because the more pie we have, we could, if we wanted to, allocate some of the leftover scraps to this poor person. But I kinda like whipped cream alot, so...., luckily for her economics tells us not to worry!
...Anyway, these irrational questions are making me get off topic. I need to get back to the indoctrination. But incidentally, that reminds me of one more term we need to understand: 'rationality'. Economics assumes that everyone is rational and that everyone has well-defined preferences and acts in their own best interest.
If we didn't make these assumptions, I wouldn't be able to teach economics. If I wasn't able to teach economics, I wouldn't be able to indoctrinate you. Were I not able to indoctrinate you, then you won't be able to be an intelligent person - and if you aren't able to be an intelligent person, then you won't be able to indoctrinate the next generation! Do you understand now Garth?"
Do you understand now?