Interesting question Sam, and one of great interest to philosophy as well as to science. For me in philosophical terms, life is a process of discrimination which means that it is by somewhat differentiating things as opposed to ‘oneness.’ It should be noted that I am not simply referring to the feeling of oneness that some people (usually religious) claim to feel for if one feels a certain way it is still a distinct feeling as opposed to not feeling at all. I think that it is possible to put up categories along this line to explain (to a degree) the different levels through which life evolves, albeit it would by necessity be a very general system.
The problem however remains in the unsurpassable jump that is needed in order for something to pass from a state of unity to a state of differentiation, but this problem is ultimately more philosophical in nature. We can probably put it off for the moment, at least until we explain the other levels that spring from it.
Therefore, starting from a state of unity and jumping to one of differentiation, where discrimination is possible in so far as either pain can be felt or in the sense of an intention to overcome pain, pleasure is produced. Although for our purposes here these can be seen as different categories with a chronology attached to them; i.e. discrimination/differentiation, pain/pleasure, intention/instinct, - these categories are not so clear cut as they may seem at first and may in fact be much more similar to each other, or even different aspects of the same thing.
In “Beyond the Pleasure Principle,” Freud elaborates on the great impact pain and therefore the instinct to reduce it; i.e. by returning to an earlier state, - have in all life forms, following its implication to the ultimate borderline, namely the death instinct. However, things cannot remain in such an uncomplicated state since a return to an earlier state demands a repetition of everything that has occurred in the evolution of previous generations (DNA, RNA information) and as such the seeking of pleasure becomes somewhat independent of the existence of pain. This by its nature is a contradiction to the death instinct and opposes it, as a sexual instinct. There are of course other complications that can be included here, such as for example the fusion of the sexual instinct with aggressive ones etc, which I will not follow here for lack of time. It will be enough to point out that a preservation instinct arises in much the same way and is not unrelated to the sexual instinct.
According to Freud the Reality Principle works only as a postponement of pleasure (demanded by the preservation instinct) until it is judged appropriate to act without submitting to extensive dangers in order to achieve one’s goal. Thus pain and its expectation introduce fear onto the scene.
There is of course much room for error here, but in general lines I think it may be a good explanation.
By this explanation, if any light was shed at all, it was only directed at living things and only implicitly on dead or non-living things. The whole, however, does become a little more organized as an order is established, from non-living, to living, to dead and the necessary cycle that follows. The borderline between these different states remains as I said earlier, indistinguishable. Considering that it was precisely the distinguishability that made possible the three different states, it comes as a paradox that we should not be able to tell apart their differences, perhaps even suggesting that distinguishabilty is indistinguishable from indistinguishability.
Pesla is going to love this :)
The Mandelbrot set would be a great visualization of what happens at the border: