When President Barack Obama nominated the Christian geneticist Francis Collins to head the National Institutes of Health in 2009, some American scientists questioned whether someone who professed a strong belief in God was qualified to lead the largest biomedical research agency in the world.
This argument -- that scientific inquiry is essentially incompatible with religious belief -- has been gaining traction in some circles in recent years. In fact, according to a 2009 Pew Research Center survey, American scientists are about half as likely as the general public to believe in God or a higher, universal power. Still, the survey found that the percentage of scientists that believe in some form of a deity or power was higher than you may think -- 51 percent.
Scientists throughout history have relied on data and observations to make sense of the world. But there are still some really big questions about the universe that science can't easily explain: Where did matter come from? What is consciousness? And what makes us human?
Where did matter come from? What is consciousness? And what makes us human?
In the past, this quest for understanding has given scientists both past and present plenty of opportunities for experiencing wonder and awe. That's because at their core, both science and religion require some kind of leap of faith -- whether it's belief in multiverses or belief in a personal God.
In chronological order, here's a glimpse into what some of the world's greatest scientists thought about the possibility of a higher power.
CORRECTION: A previous version of this story stated incorrectly that Francis Collins was born in 1960. He was born in 1950.
Also On HuffPost: