The term naive empiricism refers to the view that knowledge only comes through empirical means (e.g. science). It’s called naive because this strain of empiricism lacks nuance and fails to recognize the amount of information, belief, and knowledge which is not acquired through empirical means. The most famous naive empiricists of the twentieth century were the logical positivists, but logical positivism fell apart seventy years ago largely due to the internal contradictions with the view.
However, you’d never know it by talking to many lay people who identify as both atheists and skeptics. Within that crowd, the dated claim that all justified belief or knowledge must conform to scientific or empirical means is surprisingly common. For example, the armchair naive empiricist will say things like this:
“If I can’t see it, taste it, touch it, smell it, or hear it, it doesn’t exist.”
“I’ll only believe in God if there is scientific evidence. For example, God could have written his name in DNA.”
Naive empiricism turns up in some strange places. Consider, for example, some recent comments from Rodrigo Duterte, the vulgar and bullying president of the Philippines. Duterte touts his own atheism and recently declared belief in God stupid. He went on to issue a surprising challenge: if anybody can provide a photograph of God, Duterte would resign the presidency. (Source)
But it isn’t just atheists and self-described skeptics who exhibit the characteristics of naive empiricism. Sometimes Christians do as well. I don’t know how else to describe this jaw-dropping, embarrassing case of popular preacher Louie Giglio citing the cruciform shape of the protein laminin as evidence for God: