I tried to word the question differently from all the "why does life want to live" questions on the internet. My question is not about the mental consciousness of being alive, but more about the chemical reasons for life.

So as bacteria (or even single cells) started to populate the earth, what made them start their processes? Why harvest sunlight for energy? Of course, bacteria don't have brains, so some chemical must be responsible for life wanting to continue itself, forcing the bacteria to produce and reproduce. What would the chemical/s be and why does it give this impulse of production?

If the chemical theory is wrong, then my other explanation would be that bacteria is there to fill the place of a "stupid" machine, to produce when the right conditions arise, no matter what happens to it. In this scenario, my take would be that some advanced civilization coded these machines to disseminate life wherever, thus populating the lonely universe. What do you guys think about this?

The 2 main questions end here, but below is the thought that made me wonder, keep reading at your risk...

I found it weird how the human body, like all other living structures, is an aggregation of cells, with the only goal of living; surely cells don't know that they are composing a bigger structure, but the body evolved to make pathways to "harvest" these harvesters. The body takes care of the cells, gives them oxygen, filters the nutrition and toxins, just so it can stay alive. Does the body know that without cells it wouldn't exist? Is the DNA the despicable figure pulling the strings to survive its trip throughout the universe? All this made me think that we too are machines coded to just inhabit a place, so life isn't erased forever from the universe. Some may ask why do all that, but I think that a life-full universe is better than a life-less one. Again, what do you guys think?

  • I made some edits. You may roll these back or continue editing. You can see the versions by clicking on the "edited" link above. Welcome to this SE! Sep 11 '18 at 20:10
  • DNA, RNA and other stuff in fact are shown to be effectively parts of TM.
    – rus9384
    Sep 11 '18 at 20:18
  • hey rus9384, thanks for the answer, but Im not really sure what TM is; could you explain a little more?
    – hey
    Sep 11 '18 at 21:04
  • Hunger is the most basic instinct. When hungry, we eat; if we eat, we tend thrive. And oddly enough, most of us enjoy it. Depletion triggers hunger. People who have suffered malnutrition often overeat.
    – Bread
    Sep 11 '18 at 21:25
  • True for big organisms, but do batceria feel hunger? I guess cells release chemicals to let bacteria know they need food, but my question is why? Why would a cell need to be hungry and use energy for processes? To survive? And why does it want to survive if it doesnt understand death? What chemicals react to signal death or depletion? Why? Sorry for all the questions, just curious...
    – hey
    Sep 11 '18 at 21:41

I think you have this a bit backwards. It's not that being alive pushes you to live, it's that if you don't live you will cease being alive.

Let's say that no life exists. Then suddenly, two equally big colonies of bacteria are formed. Bacteria in colony A have a way to sustain themselves (use energy/matter from the environment, say photosynthesis) and ones from colony B don't.

Colony B will eventually die off completely as all of its members run out of their own energy/matter as living expends it over time.

Colony A may or may not survive. If it does, would you say that A bacterias wanted to live and that's why they do photosynthesis? And if yes - would you say that all live does that given that colony A bacterias are the only life left to observe?

It's just that only life with viable survival strategy stays alive (survives). That doesn't mean said life "came up" with said strategy "in hopes" of staying alive.

Some organisms do in fact want to stay alive. But that is because the mechanism of having such wants (or any) proved to be a better survival strategy than the alternative for their species.

  • 1
    If you have any references (with relevant quotes) to people who take a similar view to yours that would strengthen your answer and give the reader a place to go for more information. Welcome! Sep 12 '18 at 15:42
  • @FrankHubeny, I would suggest readers take a look at Wikipedia's article on natural selection. If you are interested in philosophers that thought in those lines you can start from the "historical development" section directly.
    – ndnenkov
    Sep 12 '18 at 15:51
  • 2
    This post does not need any citations. It is a self contained logical argument.
    – user34017
    Sep 12 '18 at 16:59
  • Hmm i see, your answer actually made me think. Of course life does not have the consciousness for being alive, but cells and bacteria do start processes, seemingly for that goal. In your example, colony A does survive, but the processes they use allow them to do so. In this case why follow those processes, why not stop? They do not gain anything, other that the fact of being alive. Why would the chemicals in the first cells of the first bacteria order to start production? are they randomly generated, like life itself?
    – hey
    Sep 12 '18 at 23:01
  • @hey yep, that was what I was implying. There were tons and tons of other organisms that didn't have such mechanisms and hence didn't survive. The only ones left to observe are the ones that happened to have these mechanisms and were following them.
    – ndnenkov
    Sep 13 '18 at 6:06

The key is reproduction acted on by selection. Follows is an explanation of evolution. This is basically the formulation that Asimov used.


Imagine a chemical process that, entirely through chance, can make copies of itself. That is, the first step of abiogenesis is complete. There are a number of candidates for what the first replicators were, but the evidence is not retained since these chemicals were very fragile. And they tended to get consumed by many other chemical processes going on around them.


Now suppose that some inheritable feature of the copying organisms determines the characteristics of the copies. The copies look and behave like their parents most of the time, including making copies. So copying also copies the "instructions for copying."

Now imagine there is a small error rate in the copy process. This results in some variations in the copied items. This is true of DNA and RNA, for example.

Now imagine that, purely by accident, some particular variation is a little better at copying itself in the conditions it happens to be in. That variation will tend to dominate, in that particular set of conditions, and become more common relative to its neighbors. This is true whether it is behavior of the organism, or efficiency of chemical process, or sensitivity to important conditions around it, or any of several other possibilities.

From this new population there will similarly be variation. This can act as a scaffold. Each variation allows a new population of variations. The most efficient copying form becomes dominant and forms a new population. And so on.

So each time this happens, the newly dominant form is a little better adapted to the particular surroundings. Thus the plaint of the puddle: There must be a god, or how could the indentation under me fit my puddle shape so well? On evolutionary time scales, the puddle is adapting to the dent, not the dent to the puddle.

Now, consider that along the way, something has to happen. Many of the individual organisms must reproduce. If they don't then they don't leave offspring, and disappear. As the old joke goes, I come from a long line of people that had children. Indeed, if there is a characteristic of a particular variation that reduces its chance to reproduce, then that characteristic will get filtered out. It's ok if some don't reproduce so long as there are many that do, sufficient to keep up the numbers.

So, for each variation, there is a filter that picks out features that mean "behaves so as to reproduce." This feature will be fixed in by every generation. In evolutionary terms, being numerous is a powerful factor.

For bacteria these are not really desires. They are chemical conditions that cause various responses under various conditions. Lots of food will mean lots of reproduction, for example. These will all be chemical signals and conditions, all very much without any input from any sort of thought process. For creatures with brains it definitely becomes desires.

Note that this process can't predict the future. It cannot form long-term goals. If, for example, an organism were to adapt to a finite resource, it could find itself in a dead end regardless of how efficient it was. Maybe it adapts to some chemical that exists in a small deposit in a particular niche in the bottom of the ocean. When that chemical is gone, so is the organism.

Note that it is relative numbers that are important. The ancestors of snakes gave up their legs to adapt to a particular niche. They out competed their immediate neighbors. They did not become universally better at competing.

Note that there are often many compromises. For example, larger eyes may enable an organism to better adapt to a poorly lit location. But larger eyes use more energy, and are larger targets for injury.

Note that a big part of the environment an organism adapts to is the other organisms. When they change the organism may find it is suddenly very poorly adapted.

So the driving force is selection acting on reproduction. Those organisms that don't reproduce as well will get out competed. Those that don't work at it very actively, also get out competed.

  • Ok, I do understand most of the answer ;) . I do see that selection is the driving force, but my question is why? Organisms adapt and survive by chemical reactions, who is weak does not make it. That seems to be the explanation for how species survive, not for how it all started though(or i did not understand the answer). Lets take cells as an example; it is true that chemicals make cells behave a certain way, but why did chemicals start a process, why just not start it at all? Do you explain that by saying that random chemicals got created, and they started a chain reaction that created life?
    – hey
    Sep 12 '18 at 22:48
  • You are now asking about abiogenesis. This is a different topic. You should ask a new question.
    – user34017
    Sep 13 '18 at 0:27

There's a problem on your question: we don't know what life is. See my answer to "is fire a living thing?" here: https://philosophy.stackexchange.com/a/47552

Nevertheless, your question is still valid. But we must reformulate the question, since we don't know what biological life is. So, instead of asking...

what pushes life to live?

... that essentially means what causes biologically living entities to persist?, we can ask instead...

What causes physical (including biological) entities to persist?

And that's a good question.

We all know that if we try to kill a living entity, it will offer an opposite reaction. But that's the exact same reaction a non-living entity performs.

It might sound stupid, but touching a rock should cause it to get damaged. A rock (or any entity) is almost empty space. When you touch it, it is reacting like a beach ball in an infinitesimal scale: it gets deformed, storing potential energy, and then it reacts, in part against your finger, in part starting to move. Why does it keeps trying to exist? It's completely obvious to our intuition, but it shouldn't.

So, I will propose two answers. Disclaimer: the second is an own idea.

  • Physical entities (including biologically living entities) try to persist due to its nature. Persistence is an inherent trait of existence. Things that exist, tend to keep such state along time.

  • This is a non-accepted idea, which I propose in my last book (avoiding publicity: if you're interested, you'll find it): physical entities might also follow Darwin's natural selection principles; living entities are just a subset of all natural entities following such principles. Natural systems are a product of physical interaction (Richard Feynman: mass is interaction). Interaction generate entities (e.g. H2O is the product of three atoms interacting). Entities must interact with the environment (e.g. hot air molecules will hit H2O molecules) and natural selection will define which entities will persist. We know entities that persisted natural selection. And we don't know those who didn't, because they were not fit enough to persist. You can think there are two types of physical entities: those which exist, having this trait of tending to persistence. There are others, which are not fit enough to persist in time, which exist at least for an instant (try building a house of cards). It's clear here that biological entities are the same as inert entities.


I suppose you really meant to ask a why question rather than a what question since a what question would be better answered in a biology SE.

The answer to a why version of this question would be the same as the answer to the antrophic principle and similar questions that have to do with evolution - namely, if it didn't it wouldn't be here.


The main observable aspect of life is its movement. Literally. #edit (apparently we're only talking about carbon life forms, so no particles we're harmed in the making of this point. big shout out to my man @rus9384 for keepin me down to earth)

If something moves, it's alive. Rocks and other stuff don't move by themselves. They don't invest any sort of energy obtained from other sources in order to move. So you can take life as movement.

But life ends at some point so it must make a little life from itself in order to continue movement. That's what drives the living: accidental movement and the inescapable desire to keep moving.

  • 1
    Then particles are alive since they move. Are you a panpsychist?
    – rus9384
    Sep 11 '18 at 20:47
  • The defining characters of life are what is technically known as irritability and reproduction. Irritability means some ability to respond to stimulus. A plant can respond to light, an animal can move toward positive stimuli and away from negative, etc. Reproduction, of course, means that the organism can have some sort of offspring.
    – user34017
    Sep 12 '18 at 17:02
  • "If something moves, it's alive" - please support this claim (which is the main claim of this answer) by any sort of mean - papers, quotes, etc. This is a huge metaphysical and terminological step to say that moving=living. If I stop moving am I dead? What are the exact characterizations would you give to "life" that'd result in the statement you give? Elaborate on answers, take time to write them. Don't just throw out claims like that. Sep 29 '18 at 22:57

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