When I first started volunteering at the University of Toronto, students occasionally asked me why. This was my answer:
When I was your age, I thought universities existed to teach people how to learn. Later, 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 teaching you is how to take over the world, because you're going to have to one day whether you like it or not.
My parents are in their seventies. They don't run the world any more; it's people my age who pass laws, set interest rates, 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, 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 when you have to.
It was stirring stuff, but it wasn't the whole story. I didn't just want my students to make the world a better place so that I could retire in comfort. I want them to make it a better place because it's the great adventure of our time. Just think: a hundred and fifty years ago, most societies still practiced slavery. A hundred years ago, when my grandmother was young, 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 we have than our grandparents did. Look at how many more things we 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. We don't think of these day-to-day decisions as political, but every time we buy one brand of running shoe instead of another or shout an anatomical insult instead of a racial one at a cab driver, we're choosing one vision of the world instead of another. We don't think about this bigger picture most of the time, 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.
At least, that's what I believed in 2004. I am less optimistic today. One upside of nuclear apocalypse from a preventive point of view was that the people pushing the buttons would pay the price. The bill for my generation's cowardice, lethargy, and greed, on the other hand, won't come due 'til my daughter is grown, by which point there will be no easy solutions (and quite possibly no solutions at all). The only things that will save us then will be more science and more courage, both of which need to be taught and practiced. Insisting on evidence, and then acting on it when the cost is immediate and the reward delayed, requires as great a social change as emancipation or universal suffrage.
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 reason I've done what I've done for the last eleven years. The world doesn't get better on its own. It gets better because people make it better: penny by penny, vote by vote, and one lesson at a time.