What do you think is the scariest metaphysical problem?

[Moloth]

I've often thought about that.  I would be strange Earth was the only place life took place in the entire universe.  Lately we have found that life exists in environments too toxic to support life--bottom of the lightless oceans, in boiling chemical vents on the surface of the planet, and other places--that support the notion that life exists everywhere it can.  What it looks like and where it is located is another matter.  But I think it is only a matter of time and technology before we find it.  And I would be willing to bet that life of some sort will be found on the moon of Europa. 

But when we do find life, that will have no impact upon any purpose I may feel I have here and now.  Nor will it make me less lonely (not that I'm lonely now).  The only purpose I serve is what I deem my purpose to be.  God, my parents, my neighbors, my boss, my wife, my children, my society cannot define my purpose--that is up to me and only me.  So, if you want a purpose, find it.

Oh, i have purpose in my life, but i'm talking more about a cosmic perspective. Its simply a mater of scale.

The chemistry of life is basically everywhere we look. the odds that earth is the only life-bearing planet, according to all i know, is so vanishingly small as to barely consider. However, as a skeptic and scientifically-minded person, i cant simply believe without real evidence

[Mike Cl]

Oh, i have purpose in my life, but i'm talking more about a cosmic perspective. Its simply a mater of scale.

The chemistry of life is basically everywhere we look. the odds that earth is the only life-bearing planet, according to all i know, is so vanishingly small as to barely consider. However, as a skeptic and scientifically-minded person, i cant simply believe without real evidence

Yeah, know what you mean.  I do 'believe' that life exists elsewhere.  But there is no scientific facts to back that up yet, so it remains a belief.  Instead of trying to kill everybody who does not believe the way the US does, and fund scientific endeavors--like going to Europa--we would be light years better off.

[Sal1981]

I find the Brain-in-a-Vat hypothesis quite scary.

[Moloth]

I find the Brain-in-a-Vat hypothesis quite scary.

Really?

I counter it with this:
I am free because I know that I alone am morally responsible for everything I do.
I am free, no matter what rules surround me.
If I find them tolerable, I tolerate them; if I find them too obnoxious, I break them.
I am free because I know that I alone am morally responsible for everything I do.
--Robert A. Heinlein

Basically, it doesnt matter what the nature of external reality is, i am still real and have agency because of my choices.

[Mike Cl]

Robert A. Heinlein!  Love his stuff!  I grok it.

[Sal1981]

Not exactly why I find it scary.

If the universe is some sort of simulation, or  we're just playthings for some external unseen force, you'd never know when the simulation ends.

[Contemporary Protestant]

I think people hopelessly follow the herd instinct

and when someone doesn't follow the instinct, they gather with other people who don't and form a herd that doesn't believe in herds