I think early humans were probably more empiricist than we are today. While lacking the accumulated knowledge we have, they were intimately familiar with terrain, biology, weather, climate, etc., for they relied on these factors every day. Failure to read the indicators meant the difference between life and death. Knowledge was integrated in small bands, not isolated. Early hunter-gatherer "religious" belief was more closely linked to reality than any "advanced" religions that came later. Today we have maniacs blowing themselves up to get free sex with seventy-two heavenly virgins, and all sorts of people, even politicians and generals, who do insane things based on stuff that's in their heads, wholly separate from reality. ("If we don't bomb the Russians or Iranians to kingdom come, Christ's return will be delayed, the gathering of the Jews to Israel won't happen, and the one-world communist government will take our guns and precious bodily fluids!") Early hunter-gatherers lacked the luxury to be wrong. They needed to base their views based on all available facts, and facts only. Arguably, today's humans have figuratively devolved as their "civilisation" has "advanced" since the rise of agriculture. We are more unequal, paranoid about each other and sex, and militarily aggressive, competitive, and violent than ever before, to not mention overpopulated.