Scottish philosopher David Hume (1711-1776) believed that all human knowledge is based on our perceptions and feelings.
The notion that our existence, experiences and feelings were the foundation for all ideas was a departure from the prevailing wisdom that science and society were disconnected. For two millennia, scientists and non-scientists had been separated - from the secretive Pythagoreans in the sixth century BC to medieval Europe, where human knowledge grew along with our capacity to become more and more specialized.
Hume used his powers of reason to calmly overturn this kind of thinking. His emphasis on experience helped bring science back to Earth and to connect it to our humanity: to who we are, what we know and what we can do.