You're missing my point.

"That's like saying there's no objective distinction between mechanical and radioactive energy. They're objectively different phenomena, in theory and in measurement."

Of course they are different material phenom - but I''m indicating that in materialism - you have the problem of only being able to define what life is, in very materialist terms - which will always fail.

So you say: "Life is these properties". Fine.

Now you can go out and measure things.

Some things are 'life' , some are 'not life'.

According to your definition.

But however you chose to define it, materially, it falls apart very quickly.

"In the case of your aliens, I would argue they are intelligent, but not alive-- sort of like a robot or AI machine."

I don't agree with this. How can you say this alien that appears in every way to be intelligent, creative, conscientious, self-aware - 'conscious' - is not 'alive'.

Let me ask you - are you 'conscious'?

Prove it to me!

--> You can't <--

By empirical, objective, materialist measure you are a biological machine - a material process - that's it.

You can say: "I reproduce therefore I'm alive"

The alien says: "I'm as alive as you are, and reproduction has absolutely nothing to do with it"

Or rather: The alien is by all accounts and every reasonable observation - 'alive'- it just doesn't fit into another, narrow mechanical view of what life is.

He makes a pretty good case.

So - however you chose to define life 'materially' - anyone can likely quickly come up with a situation in which you have the appearance of 'consciousness/life' that breaks those rules.

It's because we're trying to define it the wrong way, using a set of rules that won't permit it.

Another hint:

The definition of 'life' that you've just offered is not cannon.

So how is it possible in 2016 that we don't have an obvious, simple, and objective definition of 'life'? How could we possibly even debating this?

... because materialism (i.e. the assumption that the Universe is a big mess of particles interacting randomly according to set of rules) - does not allow for it.

You may chose to identify certain 'patterns' as 'life' - but your choice of what constitutes life is completely arbitrary.

"Saying that life is not objectively real is nonsense. "

Really, this is false. It's only 'real' if you arbitrarily define a set of processes to be 'life'.

You'd basically be defining 'life' as just a set of mechanical properties - that is really insufficient for describing what we all observe in 'life' - which is to say something transcendent.

Trying to define life in material terms is actually, kind of 'ridiculous'. We like to try it, because it's the only way we know how to be objective.

But - I'd argue that 'life' is the expression of something - not the existence of material components.

And I'm not making this argument out of opinion - it's rooted in what any normal person would consider to be 'alive' vs. 'not alive'.

"That which is expressed" - not the mechanical details of that expression.

Biology (and physics) is ultimately a useful tool for some things, but it is not ultimately going to help us find the answer to what 'life' is, in many ways, it will send us in the wrong direction.