I understand what you are trying to get at here, and maybe I will try to explain something about set theory and definitions. I hope this helps you.

In your man-human analogy: man is a SUBSET of HUMAN, thats fine.

To define something, you really want to approximate what that set is about. You cannot define a man by saying that his minimum criteria is that he must be human. There needs to be more specificity: i.e. what distinguishes men from other humans?

At the moment you are defining life by saying that whatever it is, it has to be something that does something to something else. Ok, that is one criteria, but it doesn't define what life is at all. It's useless. The criteria is so general that an almost infinite (or at least very very large) number of things can fulfil it. You need more criteria, much more.

It's like saying that the minimum criteria that defines a dog is that it must be an organism with teeth, capable of eating meat. Yes, dogs fit this criteria, but this criteria doesn't define a dog.

Yours is not a criteria that can define "life". Sorry.

Bugsy,

Gee, I simply cannot resist leaping back to this topic.

Thanks for the comments.

You misunderstand where I was coming from though.

In terms of set theory, my attempt was really to first identify a "Super Set" that all life-forms must belong in. If an almost infinite number of things fit in this "Super Set", then so be it. It's a good place to start from.

Such a "Super Set" must corresponds to a minimalist criterion, agree?

The next step (I suppose) is to reduce the "size" of this "Super Set" to exclude non-life out of it, as much as possible. For instance, do this by codifying the "process" in the minimum criterion and/or increasing the number of inputs/outputs that a life-form must be able to process.

One reason for an all-encompassing "Super Set" (hence my minimum criterion) is facts that we do not understand how some viruses operate and we need to cast a wide net. Could it be possible some viruses satisfy that minimum criterion, but no more. In which case we have a "Super Set" that maps directly to those viruses.

To define life-forms of a higher order (eg. cats & dogs) is to move away from the boundary that separates life from non-life. What is important is to identify that boundary, not that we need to define a complex life-form.

Do I make some sense?

Gz, the evolution theory is about how existing life has developed; it makes no claims about the origin of life as it begins with the premise that life already exists.
Whether the origin of life took off naturally from non-living material or was created by God, the evolution theory explains development of life- not origin of life. Even if someone discovered that God created the first inchoate live form, evolution’s evidence would still explain how life has developed from there.
The line between the two can be confusing though- they may sometimes appear to overlap especially since evolution biologists have a keen interest in the question where life exactly begins.

I don’t really grasp what your aim is in regard to “Super Set… minimum criterion”. Science has worked out already what life (and non-life) is away from the boundary- the difficulties with defining life merely exist along that boundary line.

gz, I am only using higher life forms as an example. Your broad "super set" though is too broad, and while it it seems that it may encompass non-living things, I suspect it may actually exclude things like viruses. Not so bad in itself, there is a school of thought that viruses are non-living and so the definition would be applicable, but probably for the wrong reasons. It also gives no indication as to how likely something is to be alive. Some organisms may only be capable of "processing inputs" under particular circumstances, and then it's quite obvious that they're alive, not so obvious under other circumstances. Eg. a dormant grain of wheat.

Definitions or criteria must be useful in a scientific sense in that they define what is actually being talked about and that people can understand exactly what is being talked about. At the moment many of the concepts outlined in your definition are subject to so many different interpretations that it is unworkable. It should be becoming increasingly obvious that you are having to explain several different concepts (eg "input", "process", "stand-alone intelligence", "output"), which are ambiguous when applied to living or non-living organisms. In this sense the definition needs much more refinement as it doesn't describe the boundary between living and non-living things (not even close), which I suspect was the original intention?

gz,

CJ's infantile behaviour is just a manifestation of his nasty personality rather than ignorance in respect of a particular topic. He wants to hurt our feelings and is surprisingly unconcerned about embarassing himself.

Bugsy,

"mjpb, in case you hadn't noticed about the only thing you have written that comes close to proper definition of science ... is:

'Science has been defined as a "method utilized in organised efforts to formulate explanations of nature, always subject to modifications and correction through systematic observation".

The rest ... confined to what you believe science isn't."

You consider it a proper definition. I agree. When I'm saying what it isn't I'm not defining it. I agree. Originally I said what it isn't is in the belief that saying what something isn't helps explain it. Subsequently I have said what it isn't in response to people giving examples of the use of systematic observation alone or explanations alone that didn't go farther or stillbirths of science. Would it be clearer if I said that if only a portion of the definition applies I don't believe it fits the definition? For these reasons I believe science got off the ground at a time period and place.

I value ancient and mediaeval non Christian examples of learning, innovation, observation or explanation just as I value science. I just don't consider them science for the reasons given above. Yes that is the same as saying that Christian Europe gave rise to the kind of science that arose in Christian Europe because that kind of science fits the definition that I believe equates to science. This is not because of some preference for that type of science but because I believe it is a reasonable definition of science. I'm not the only one. People who call Gallileo the father of science must be saying the same thing. However people who use the label science to historical figures as far back as Sumerians appear to subscribe to another definition. They keep denying it and I'm trying to make sense of that anomaly.

I googled this early on in the discussion and was planning on using it to better express something I believed but the topic keeps spiralling away. It is from someone at Columbia University who wants to share the opinion of someone called Stanley Jaki who argues for the birth of science being due to Christianity. To be honest the main reason I'm putting it here is to keep it somewhere I can find it but it deals with something that has been touched upon in here.

http://www.columbia.edu/cu/augustine/a/science_origin.html