For example, a hard-core physicist writing on the subject of micro-genetics can describe molecular sequences that can account for every change in a cell. And can describe every change in an organ as a series of changes in cells. And can account for every change in an organism as a change in its component organs, including the brain and nervous system. These molecular sequences, it can be argued impressively, define the very quick of life and raise the very question of death.
Examining the tortuous habituation to the forms and frequencies of material and biological science the depressing truism comes forth that all the myriad miracles of life can be found in cells, which in turn can be fully diagrammed in terms of perhaps two thousand purely chemical reactions between carbon, hydrogen, phosphorous, nitrogen, and other elements.
Now this may be true, and it may well not. Certainly the facile presentation of every transformation involved in all of two thousand chemical changes involved in cell structure does not itself prove its own premises and assumptions. For example, there is inherent in the assumptions of physical science that time is a certain way; that the spectrum of the physical elements is the substance of physical phenomena; that space has a continuity in fact as it does in apparency; and that the apparency of space (and things in it) is there for us to look at, explore and discover and not simply the by-product of thought-patterns, beliefs, of projections of some sort from a different quality or frequency area altogether. These assumptions are mandatory for our physical sciences in application, and their application is really the only argument that supports them. For many people this seems like a persuasive but underhanded PR campaign.
Why we as scientists are certain that the physical universe around us is the show, rather than just a preview or worse yet just a channel-selection indicator light, is hard to say.
But out of charity one should, I suppose, try on for size the belief that all of life IS contained in these reactions; that the molecular shifts account for all the desires, fancies, visions and virtues of the human being, and that nothing in the realm of molecular, atomic, sub-atomic or macro-biological science justifies any leap to vitalism. This leaves us with a dry existential view of things: intention is merely the waggle of electrons; ethics, the self-perpetuated hologram of some very intricate strings of amino acids twisting in a certain way; aesthetics, nothing more than the un-informed humming of a kind of crystal radio receiver in response to its appropriate frequencies, and emotion entirely attributable to an imbalance in, say, citric acid or some pre-cursor in brain molecules.
If this is so, then the best of thought itself is holographic self-persuasion. The impressions of life outside the body are impressions of chemically-driven projectors within the neurological paths of cells in the brain Your impression of "All that is" is only a picture of what "all that is" might look like if one were more than a brain in a shell being driven around by a carbon-oxygen engine.
Something about this model does not sit right; taking it one step further, for example, its implications for death (individual death) are the blank nothingness of Un-existence -- the death of a poet being no more or less than the decay of a brick or the death of a single cell. This is fretting to some people to contemplate, and to others a funny sort of paradox. The paradox is something like that of a movie projector projecting on a screen a film of the projection booth -- but in the projected picture, the projection booth with the projector removed. The movie projector, somehow sentient, observes this picture of its surroundings without it in them, and frets over the possibility.
This is an analogy that seems scraped and twisted. What brings about the image? How does that picture get on the screen? How did the screen itself, reflecting the particles of light which form the image, get to be what it is and where? How was it determined that certain parts of all the energy around would make up an image, through what lens, and how is the meaning of image itself decided upon? Can the meaning of those selected wavelengths be changed if the image is shifted to include, say, something more in an ultraviolet band? And finally, if meaning itself, interpretation and understanding and very consciousness only a biochemical shift, is "awareness of being aware" more than that? And how many iterations can this process take?
And, perhaps more important, who wrote this damn script anyway?
One reason to protest is that the belief system (within which these biochemical truths are so convincing) is a system of premises which are themselves invisible in the experience which supports the conclusions. One of these premises is that time is as it seems to be in these events, a hangover from Newton's perfect mathematical belief in Time. Another is that the evidence of the wavelengths from optical to solid (and slightly higher as used in electron-microscopy) irrefutably reflects the entire system within which it is found. This may not be the case -- the wave-lengths that make up these phenomena may in fact be a minor aberration in a small part of one frequency band, a leak from some entirely different arrangement, the accidental tip of one corner of a fizzy iceberg.
A related reason is that the system within which these beliefs operate may itself be the hologram, and not the source, of life. There is something deadeningly Sourceless about the "string of chemicals" interpretation of life's wonderfully busy business. There is evidence that all biochemical change is preceded by some sort of electrical or electromagnetic field adjustment; where does that come from?
To put it another way, observe that any part of a movie is part of a movie. To believe from this that experience is a movie is like being stuck on the screen, not truly in the audience at all, let alone projecting the film and certainly not writing the script which prompted all the machinations preceding the perception of picture on the screen.
All these factors lie behind the unease that consciousness might experience, if it chose, in considering the idea of death as an extinction of consciousness.