You could say that the modern age really began in Europe in the 1600s. Around this time, people began to ask for proof before they were willing to believe something. No longer were they willing to accept something as fact just because it was what they were told. They wanted facts. They wanted things to make sense.
It was called The Age of Enlightenment, and its main idea was that humans had a very important power - the ability to reason. It was believed that this ability to reason would allow people to break away from the superstitious beliefs of the past.
It was a radical new way of thinking for many Europeans. For centuries, they had accepted the teachings of certain leaders. If the leaders said that something was true, then it was. At one time, that would have been the end of the story, but not any longer. Now people used their own abilities to discover truths for themselves.
Since all humans had this ability to reason, the Enlightenment philosophy led to a new way of looking at people as well. It led to the idea that all people were equal. Anyone could make important scientific discoveries, not just members of the noble class or members of the clergy. Also according to the Enlightenment philosophy, everyone has certain natural rights.