This weekend we will celebrate Canada Day, marking 145 years of this country's existence as an independent nation.

It's a good time to put your feet up, sip something cool, enjoy some sunshine (we hope) and relax for a bit, basking in the lives we can lead in one of the richest and most peaceful nations in the world.

It's also a good time to remember, between flipping the burgers on the grill, that Canada is a moving target.

We're not the same nation at 145 that we were at 144, or in the centennial year of 1967, or in during the wars or in the throes of the Great Depression. This country is, like every other country in the world, an ongoing experiment in politics, sociology, and economics. The results of that experiment will determine if Canada celebrates its 200th birthday, its 300th, or its 500th.

If Canadians have any advantages as we look into the future, it's that we can't help but be aware of the fact that we are an artificial creation. We're not some monolithic ethnic group or insular clan. We are the result of countless decisions and compromises made by explorers and First Nations, map makers and war makers, francophones and anglophones and allophones.

They carved a nation out between early colonialism, staved off the Manifest Destiny of our friends to the south, and then pried themselves loose from the somewhat stifling embrace of Great Britain.

Since then, Canadians have proven adept at making war and keeping peace, at science and business, at both taming a vast landscape and appreciating its undisturbed grandeur.

We know that there is no perfect, finished Canada. The experiment will never be over, really. We have screwed up more than a few times over the past 144 years. We're making mistakes right now that our grandchildren will have to correct, and they'll make mistakes of their own.

If they're lucky, they'll be able to have a day to appreciate the good choices we made. - M.C.