Good article on the "dismal science"

This is an excellent article explaining how and why economists think the way they do

http://www.smh.com.au/news/opinion/reasons-to-be-happy-about-the-dismal-science/2006/09/12/1157826940159.html?page=fullpage#contentSwap1

This paragraph is related to what I discussed in last nights class

"Economics is dismal because it grapples with the problem of scarcity, which arises because, though our wants are infinite, the resources available to satisfy those wants are finite.
From this comes the first way in which economists make themselves unpopular: by banging on about "opportunity cost". This is the notion that anything you decide to do has a cost, which is the thing you can no longer do. A dollar can be spent only once, so if you spend it on A it's no longer available to be spent on B or C or D."