Richard Dawkins
Evolutionary biologist, Oxford University; author, "The Ancestor's Tale"

I believe, but I cannot prove, that all life, all intelligence, all creativity and all "design" anywhere in the universe, is the direct or indirect product of Darwinian natural selection. It follows that design comes late in the universe, after a period of Darwinian evolution. Design cannot precede evolution and therefore cannot underlie the universe.

This is related to this post.

[jackdied] A few of the people touched on culture and its effects as the answer to "know, but can't prove" which rhymes with Hayek's "mess with Culture at your own peril" message (to stretch it out, "how sure are you that you are right and millions of people over hundreds of years are wrong? And you are asking them to prove that you are wrong?"). Here are excerpts of the "culture" answers (although not all of the scientists called it that):

• Roger Schank: Irrational choices. People believe they are behaving rationally and have thought things out, of course, but when major decisions are made - who to marry, where to live, what career to pursue, what college to attend, people's minds simply cannot cope with the complexity. When they try to rationally analyze potential options, their unconscious, emotional thoughts take over and make the choice for them.
  Does your family vet your girlfriends? Does you mother nag you to go to grad school? Has anyone ever Tsk-Tsk'd you? Culture steers and shapes our choices, "tsk-tsk" is the most underrated force in the West - humorously enough where it is met with a "tsk-tsk!" I don't think Schank is wrong, he is just thinking too narrowly of the individual and not their environment.
• David Myers: There is a God. The whole truth cannot be found merely by searching our own minds, for there is not enough there. So we also put our ideas to the test. If they survive, so much the better for them; if not, so much the worse.
  This "survival" sounds a lot like "mess with Culture at your own peril."
• Judith Rich Harris: I believe, though I cannot prove it, that three - not two - selection processes were involved in human evolution. The third process selects for beauty, but not sexual beauty - not adult beauty. The ones doing the selecting weren't potential mates: they were parents. Parental selection, I call it.
  She may be talking about infanticide, but I'll chalk this up to reinforcing behavior by picking a "favorite son."

I believe that consciousness and its contents are all that exists. Space-time, matter and fields never were the fundamental denizens of the universe but have always been, from their beginning, among the humbler contents of consciousness, dependent on it for their very being.