freethinker

noun

Etymology: From free + thinker, since 1692.

1. A person who has formed their opinions using reason and rational enquiry; somebody who has rejected dogma, especially with regard to religion.
2. A person with no religion.

   “The report projected that in the Asia-Pacific region, the proportion of freethinkers is projected to decline from 21 per cent in 2010 to 17 per cent in 2050.”