Something quite extraordinary happened in Europe during the 17th and 18th centuries: the diversified intellectual explosion called the Enlightenment. Philosophers, natural scientists (the divide between the two wasn't that wide then), artists and political scientists created a revolution in thought based on equal rights for men the freedom to reason without constraint.
Admittedly, it was a relative equality, with some Enlightenment philosophers mistakenly placing white men at the apex of society.
But, as a general rule, the core message of the Enlightenment was the need to create a global civilization with shared moral values. This overarching intellectual framework was far removed from traditional religious precepts. In fact, the Enlightenment declared war on the excesses of religion and blind nationalism.
Adam Smith, for example, saw patriotism extending beyond one's own country to the great society of mankind. Immanuel Kant called this "global patriotism." We can identify the influence of these ideas in none other than Albert Einstein, who believed in a need to abolish international borders.
"In my opinion there is no other salvation for civilization and even for the human race than the creation of an international government with the security on the basis of law," he declared in a September 1945 interview.
When we revisit these ideas today, we notice that the globalization of free-flowing information has realized part of the Enlightenment program. Political frontiers still stand, while ideas move at light speed across the planet. There is an emerging perspective, that of the planetary citizen.
Will this lead to a new Enlightenment? Or are the same age-old rifts simply going to get amplified by the hundreds of millions of anonymous voices claiming authority over the Web? Should we spend our time considering whether every opinion is equally valid or should we aim collectively for some higher goal? (Of course, the problem is to decide what this goal would be.)
In the past, I have suggested that modern astronomy offers a new vision for humanity, which I called humancentrism. Essentially, humancentrism is an inversion of Copernicanism. While Copernicanism states that the more we learn about the cosmos the less important we become (so, a doctrine of human insignificance in the grand scheme of things), humancentrism states the opposite.
As we scan the skies in search of other Earth-like planets with missions such as the sensational Kepler satellite, which has found thousands of exoplanets, and learn more about the history of life on Earth, we learn something new and essential about our planet and who we are.
Even if there are other planets or moons with properties like Earth (similar mass, liquid water, oxygen-rich atmosphere, etc.), our planet and its geophysical properties are unique. (A large moon, tectonic plates, thick atmosphere, magnetic poles.) These properties are a key ingredient in the success that life has had here, in particular by providing long-term climate stability and protection from harmful cosmic radiation. Standing on this propitious background, single-celled bacteria evolved to multicellular, complex multicellular and, finally, intelligent multicellular life forms. Each one of these steps was delicate and improbable. Most were also deeply linked to the planet; some of them transformed Earth itself, like the oxygenation of the early atmosphere. We have thus learned that if there is complex life elsewhere, and we can't determine either way yet, it will be rare and certainly very distant from us. In other words, in practice we are alone.
We matter because we are rare.
If the philosophes from the Enlightenment knew this, I imagine they would have expanded their global stance for humanity to a cosmic stance. A complex molecular machine capable of wondering about its existence should also celebrate and respect its existence. And since we are here only because Earth allows us to be (no teleology implied here, only stable geophysical conditions), we must also celebrate our planet as being unique.
Human reason, that leads us to comprehend our place in the universe, leads us also toward a new moral imperative, perfectly secular in its values: the equality of all creatures and the preservation of life and of this planet.