El escepticismo tiene por función ser peligroso. Es un desafío a las instituciones establecidas. Si enseñamos a todo el mundo, incluyendo por ejemplo… - Carl Sagan

Imagine how different our world would be if those discoveries had been explained and used for the benefit of everyone, if the humane perspective of Eratosthenes had been widely adopted and applied. But this was not to be. Alexandria was the greatest city the Western world had ever seen. People from all nations came here to live to trade to learn, on a given day these harbours were thronged with merchants and scholars and tourists, it's probably here that the word Cosmopolitan realised its true meaning of a citizen not just of a nation but of the Cosmos, to be a citizen of the Cosmos. Here were clearly the seeds of our modern world, but why didn't they take root and flourish why instead did the Western world slumber through a 1000 years of darkness until Columbus and Copernicus and their contemporaries rediscovered the work done here? I cannot give you a simple answer but I do know this, there is no record in the entire history of the library that any of the illustrious scholars and scientists who worked here ever seriously challenged a single political or economic or religious assumption of the society in which they lived. The permanence of the stars was questioned, the justice of slavery was not.

I maintain there is much more wonder in science than in pseudoscience. And in addition, to whatever measure this term has any meaning, science has the additional virtue, and it is not an inconsiderable one, of being true.

Claims that cannot be tested, assertions immune to disproof are veridically worthless, whatever value they may have in inspiring us or in exciting our sense of wonder.