How do we know what is true? Each of us has a very narrow range of issues on which we have enough direct knowledge to answer that question. Matters of direct experience: our families, our neighborhoods, the range of our daily activities, that about does it. For all the rest, we have to rely on information from others, and we have to have a sense of how much to trust those sources.
We live in a time, long predating Donald Trump and “fake news,” when we have trouble agreeing on whom to trust. A thousand years ago in Europe, the Church filled that role, teaching us the Truth about God, Christ, the world and the right ways to live our lives. There was no other authority.
On the whole, those who see religious teachings as their primary window on the world are more likely to disbelieve science. Those who see science as their primary window on the world tend to be nonreligious.
But Church authority progressively broke down: first Islam, then Orthodox Christianity, then the inexorable splintering of the Protestant Reformation, then the Renaissance, the Enlightenment. By the time of the American and French revolutions there were so many claims to religious authority that the American founders amended the Constitution to prohibit any established (i.e., state-supported) religion. The French established a Republic that was militantly secular, independent of any religion.
Within Western societies two broad currents emerged. One celebrated the end of religious hegemony and the emergence of the natural sciences as the superior way to gain understanding of the world. Scientists like Charles Darwin became the indispensable interpreters of the world, fulfilling the role of priests to the nonreligious.
The other current insisted on the religious approach to interpreting the world, notwithstanding the ongoing fragmentation of religious authority. So the leaders of each religious sect, or even of individual congregations, were relied upon to help their faithful interpret the world. The sects varied widely in their attitudes toward science, from explicit acceptance by some liberal Protestants (and most Jews) to a militant rejection by some fundamentalists, particularly of evolutionary biology.
This pattern persists right up to the present: substantial sectors of religious conservatives are the mainstay of skepticism about human-caused climate change, for example, while support for that paradigm is found particularly among the nonreligious. There are of course inconsistencies. There are still many religious people who accept human-caused climate change as a reality, and they are usually helped to that conclusion by their religious leaders in denominations like the Episcopal Church or the Unitarian Universalist Association. And there are secular conservatives like Donald Trump who are climate skeptics. Religious conservatives don’t reject all science, only what seems to contradict scriptures as interpreted by their leaders. The nonreligious and religious liberals don’t accept all science: witness skepticism about vaccination, or about genetically modified foods.
But the broad pattern remains: on the whole, those who see religious teachings as their primary window on the world are more likely to disbelieve science. Those who see science as their primary window on the world tend to be nonreligious.
Where once everyone could turn to the priest for definitive answers about the world, we have now reached the logical conclusion of a millennium of fragmenting authority: each of us is our own priest. In the Facebook Age, no one but ourselves can tell us what is true.