I am optimistic again. Let me tell you why.

When I was very young, the world was an uncertain place. 1968 was a turbulent time, with an unpopular war, multiple political assassinations, and a steeply rising crime rate.

That fall would see the election of a president who would soon face legal pressure to resign. Protesters were shot by our own military. Domestic terrorism would plague the country for a decade.

Around the world, starvation was rampant, poverty seemed intractable, and an out-of-control population bomb promised to make these problems ever worse.

More than all this, though, we lived in the shadow of imminent destruction as two superpowers aimed nuclear death at one another. No one knew if democracy could survive the challenge of totalitarian communism, and at times it seemed that every country’s government faced the threat of violent overthrow, fueled by either our own Western governments or those of the Soviet bloc.

This is the world I grew up in. Now let’s look at today.

(By the way, I know many of you, of all political persuasions, will not believe what I’m about to write. You are convinced that things are terrible, maybe worse than ever. I urge you to look at the data. In particular, read books by Steven Pinker, David Deutsch, Matt Ridley, Max Roser, and Hans Rosling.)

The threat of totalitarian communism has disappeared. There were many reasons for its decline, but chief among them is this: liberal democracy is a better system. Democracy is ascending all over the world, because people want it.

The world is more peaceful than at any time in history. Yes, there are still wars, but nowhere do we have the level of violence and bloodshed that characterized the wars of religion in the 16th and 17th century and the world wars of the early 20th century. The level of violence compared to these events barely registers.

In addition to international peace, we have domestic peace. Crime rates started falling in the 1990s and are still on the way down. I know it doesn’t feel that way. Again, I urge you, look at the statistics. We are far more peaceful today than we were only a few decades ago.

Poverty is plummeting. Not just decreasing – plummeting. Two hundred years ago 90% of the world lived in extreme poverty. That left only 10% not in this condition. Today the numbers are exactly reversed. Only 10% of the population lives in extreme poverty. Certainly 10% is still too high, but surely this is monumental progress – particularly considering that in the 10,000 years of civilization that proceeded it no discernible progress was made at all!

And one feared result of all this peace, freedom, and prosperity – the fabled population bomb – has fizzled. It turns out that when people are healthier, freer, less fearful, and (maybe most important) better educated they have smaller families. They put more resources into the children they have. They invest in the future.

And that brings me to the point of this post. As Pinker writes, “The point of calling attention to progress is not self-congratulation but identifying the causes so we can do more of what works.”

After World War II, the world in a sense said enough of this. We made warfare illegal. Yes, wars still happen, just as people still rob banks. But international norms and institutions prize peace and work hard to defend borders and pressure all nations into being good actors. By and large, it has worked. Again, if you don’t believe me look at the data.

We set up international trade networks. My leftist friends will hate this, but the fact is that trade works. It creates relationships that prevent violence. Gentle commerce has made the world not only more prosperous, but far more peaceful.

We committed ourselves to eradicating disease, ending hunger, curing poverty and teaching the world to read and write. We’re not there yet, but the trajectory is clear. It’s working.

And this is my point. When I was born in 1968, we didn’t know. The great experiment that followed the horror of World War II was still too new. We couldn’t be sure any of it would work.

Now, fifty years later, we know. The world is getting better. It isn’t an accident. It isn’t luck. It’s because the tenets of liberal democracy – free trade, gentle commerce, democratic institutions that protect not states’ rights nor national rights, but individual human rights – and so many others, are working.

There are still monumental problems – not least of which is how do we keep all this prosperity from destroying the environment. But as David Deutsch tells us, problems are soluble. Everything we try from here on out is an experiment – it’s never worked before. But we are in so much a better place than we were in 1968, because we have a record of what has worked to get us here.

I believe we need to stop making decisions based on ideology. Instead we need to become pragmatic. We need to base decisions on data, on hard numbers and facts. We have the ability to do so. We have the required knowledge to use as our starting point. We have the mathematical tools to analyze data and make decisions based on that analysis. We have the resources to check spurious claims and call them out for what they are.

When someone makes a claim, instead of reacting with a counter-claim that just feels right to you, I urge you instead to ask for data. What evidence do you have that supports your claim? You claim that illegal immigrants are overrunning the country. What is your data? You claim that crime is rampant. Data, please. You claim that free trade is destroying the economy. Let’s look at the numbers.

Beware of those claims you want to believe. Remember the easiest person for you to fool is yourself. Look at the data, question your own beliefs, and remember that, as journalist Sylvia Strumm Bremer wrote in 1950, “A lot of the nostalgia for the “good old days” is just the result of a poor memory.”

We are getting better. Let’s keep it up!