Every term, a few students ask me why I teach when the university doesn't pay me for doing it. Here's the answer I gave a CSC207 class at the University of Toronto in December 2003:
When I was your age, I thought universities existed to teach people how to learn. Later, when I was in grad school, I thought universities were about doing research and creating new knowledge. Now that I'm in my forties, though, I've realized that what we're really doing here is teaching you how to take over the world---because whether you like it or not, you're going to have to one day.
My parents are in their seventies, and retired. They don't run the world any more; instead, it's people my age who pass laws, decide whether interest rates will go up or down, and make life-and-death decisions in hospitals. As scary as it may be, we've become the grownups.
Twenty years from now, though, we'll be heading for retirement, and you will be in charge, because there won't be anyone else to do it. That may sound like a long time when you're nineteen, but let me tell you, you take three breaths, and it's gone. That's why we give you problems whose answers can't be cribbed from last year's notes. That's why we put you in situations where you have to figure out what needs to be done right now, what can be left for later, and what you can simply ignore. It's because if you don't start learning how to do these things now, you won't be ready to do them on your own when you have to.
Stirring stuff, isn't it? ;-) But it's not the whole answer. I don't just want my students to make the world a better place so that I can retire in comfort. I want them to make it a better place because that's the great adventure of our times. Forget about landing on the moon and unraveling the genetic code: when future historians write about our era, what they'll focus on is that for the first time in history, our species started taking the Golden Rule seriously.
Just think: a hundred and fifty years ago, most societies still practiced slavery. A hundred years ago, when my grandmother was a young girl, she wasn't legally a person in Canada. Fifty years ago, most of the world's people suffered under totalitarian rule; in the year I was born, judges could---and did---order electroshock therapy to "cure" homosexuals. Yes, there's still a lot wrong with the world, but look at how many more choices you have than your grandparents did. Look at how many more things you can know, and be, and enjoy. And most importantly, look at how many other people can too.
This didn't happen by chance. It happened because millions of us made millions of little decisions, the sum of which was a better world. For the most part, we don't think of these day-to-day decisions as being political, but they are. Every time we buy one brand of running shoe instead of another, every time we choose to take this class instead of that one, every time we give the homeless guy on the corner fifty cents (or don't), every time we decide to shout an anatomical insult instead of a racial one at a cabbie who shouldn't be allowed to drive a shopping cart, we're putting our weight behind one vision of what the world should be rather than another. We don't think about this bigger picture most of the time---we'd be paralyzed if we did. But the last century and a half shows that once enough people make "doing the right thing" a habit, the big picture more or less takes care of itself.
In his 1947 essay "Why I Write", George Orwell said:
In a peaceful age I might have written ornate or merely descriptive books, and might have remained almost unaware of my political loyalties. As it is I have been forced into becoming a sort of pamphleteer... Every line of serious work that I have written since 1936 has been written, directly or indirectly, against totalitarianism... It seems to me nonsense, in a period like our own, to think that one can avoid writing of such subjects. Everyone writes of them in one guise or another. It is simply a question of which side one takes...
Replace "writing" with "teaching", and you'll have the real reason I'm taking on twenty students next term. Every line of code you write changes the world in some small way. Every deadline you meet, every security hole you don't plug, every user need you satisfy, every disability you don't accommodate---each one makes tomorrow different from today.
That's why I teach. You're shaping the future we're all going to spend the rest of our lives in. I want you to do things right, and to believe that doing things right is important, because the world doesn't get better by chance, or on its own. The world gets better because people like you make it better: penny by penny, vote by vote, and one line of code at a time.