: All we know is that Life exists, and it has only ever been seen to
: reproduce from existing Life, and no one has created a living entity (by
: our own 'common understanding' of life), from non-living material. That's
: the observation . We can interpret those observations as evidence to
: support what we believe - whether there is or is not a 'spark of life'.
: Because it has not been observationally determined one way or another.

We know that the universe started off sterile because there was no matter. It took time for the universe to cool enough for particles to form. Even then it was a plasma of protons, neutrons and electrons.

Later there was mostly hydrogen, some helium and trace amounts of Lithium. There was no carbon, nitrogen, oxygen, phosphorus, calcium, sodium, or sulfur. These came later, formed in stars and seeded throughout the universe by stellar explosions. So we know that life didn't always come from preexisting organisms because organisms didn't always exist.

: Well then, you may ask, what is the definition of life? If you say there is
: no 'spark of life', then you may as well admit that there ultimately is no
: "life", that machines and humans must fundamentally be the kind
: of entity - just a mix of atoms that can do things autonomously, even be
: self-sustaining, and present the capability to 'think'. I think you'd find
: the vast majority of human civilization would take issue with that.

You don't need magic to have life.

Life can be life, it doesn't have to have a spark - whatever that is. It adds nothing to what is already there.

Essentially you are saying that people are shit, animals are shit and the universe is shit. All that we see is nothing - only the presence of a magic spark gives us worth.

Our opinions, actions, thoughts, bodies - all shit.

My opinion is that what we see is enough. people matter to me irrespective of whether there is something that we can't detect. What we can detect is enough for me. My feelings, my actions, the thoughts and actions of others are enough for me to care about them. I don't have to invent fictions in order to respect other people.

What would you do if we detected this vital spark? What would you do if we understood it? Could generate it? Convert it to and from electricity? Knew its units and understood its physics?

Would you say that if we were just vital spark then we were nothing?

We understand chemistry, we can do the math. Does that make chemistry shit? Why would being a product of chemistry make people worthless in your eyes? Do you not respect what we know and experience of people as they are?

: Alas,
: going back to an initial comment of mine - that's precisely the topic of
: conversation I love to have explored in science fiction: the nature of
: "Life". IS it biological? Or is it philosophical? Cultural?
: Religious? Supernatural? etc. What is life, and how does that play into
: human morals and ethics in how we treat each other?

I don't think that inventing fictions helps one iota. It doesn't make us any deeper or better as people. Would you stop respecting people if we could make them in a machine? Would people loose their worth to you?

: If you have no convincing evidence that X does not exist (let alone any
: proof), let's just assume for now that it does.

No, definitely not. That way lies madness. We would have to accept all propositions - especially the more formless and non-nonsensical ones (the hardest ones to understand or reason about).

: No, you are starting from an assumption - you are framing the topic of the
: existence of X within the framework already that it does not exist,
: therefore anyone who says it does has the "burden of proof" -
: and that's exactly my point. You're starting on an assumption. Regardless
: of how "reasonable" the assumption is, it's still an assumption.
: And yes it is possible to prove a negative, if your perspective of
: observation is from outside the boundaries of the model in question.

No. A is a positive claim. Not A is a negative claim. The burden of proof is on the positive claim.

By default we reject positive claims until we are presented with sufficient evidence to take them seriously. It is a time saver and a bullshit reducer.

: Prove to me a goldfish is not in the bowl. Easy! You look at the whole of the
: bowl, and there is no goldfish. You might swirl a net around through the
: water inside to make sure there are no mirrors hiding the fish; that the
: fish isn't somehow transparent, or very tiny. Observation and
: experimentation covering the entirely of the proposed model will prove
: that there is no goldfish (defined by a visible golden fish-like entity)
: inside the bowl.

Doesn't work when the claims involve the existence of things that we can't demonstrate. For example: there is an invisible pink unicorn in the corner of the room. And in addition: it is inaudible, intangible, has no smell and gave mankind intelligence. Please disprove.

Or

The harmonious colors of the rainbow gives us our harmonious sense of morality. Disprove! Bonus points for disproving without recourse to personal incredulity.