In ethics, the idea that lives, in and of themselves, are valuable (with a complete disregard of the consequences that followed from that life) is often used to prove some point, but the claim that lives actually are valuable is seemingly an unproven premise which stems more from intuition than reason.

My question is, what are some arguments made in favor of this claim by philosophers? Why are lives intrinsically valuable?

I think the question is quite deep. Note that one cannot give an answer such as "lives are the source of happiness, love, friendship, etc", since those are consequences that sometimes follow from a life. But they are not intrinsic qualities of the abstract concept of life, and certainly many lives do not produce those qualities, in fact it is often the opposite, meaning one could just as easily say "lives are the source of pain, suffering, sadness, anger, etc".

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    The theory of evolution claims that life exists not because it should but because it can, so life and death, according to it, are equally in harmony with the natural order of things. The value of life, on the other hand, is the measure that life should be guarded against this natural order. Consequently, any theory of value must somehow account for tendencies that often war against the normal course of nature. This dilemma is easily resolved when we take into account that God created us in His own image, and for that reason we have value.
    – user3017
    Commented Oct 19, 2017 at 2:17
  • @PédeLeão : The theory of evolution does not assert that life, or anything else, "exists because it can". If your position relies on the assertion that anything which can exist must exist, you've got a few intermediate steps to fill in.
    – WillO
    Commented Oct 19, 2017 at 18:33
  • @WillO. Claiming that life does exists because it can is not the same as claiming that it must exist. I believe the former is what the theory of evolution does actually assert, but it's not my claim at all. The theory of evolution is full of holes as far as explaining life or a whole host of other things. My point is simply that it's a claim that addresses a matter of fact as opposed to a normative claim; the fit survived because they were able, as opposed to there being any reason they should survive.
    – user3017
    Commented Oct 19, 2017 at 19:11
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    If you accept a principle of equality, you could say: "my life is valuable, therefore I must accept that other life is also valuable". Of course, how far "other life" goes depends on what other life you consider equal (specific race? humans? animals? plants? fungi? rocks? [not alive under traditional definition, but who knows]).
    – user935
    Commented Oct 19, 2017 at 21:16
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    This is often discussed under the meaning of life heading, the linked SEP article describes both religious and non-religious approaches.
    – Conifold
    Commented Oct 23, 2017 at 19:51

6 Answers 6


I think you're right in a sense that "lives are valuable" is generally a working assumption in ethics rather than a claim which is argued for. I'm familiar with four honest arguments for it and one semi-honest one.

First, one can raise a theological argument that human lives are valuable because they are created by God or in the image of God (two variations there). This isn't limited to just the monotheists. It could be applied equally to "we are all the emperor's children" as in state Confucianism or to many animistic religions.

Second, one can raise a separate theological angle that we are commanded to value life. Here, the idea is that in divine command theories we can arrive at values because we are commanded.

Third, on Kant's ethical theory, human life is valuable because human life is rational. In other words, we have worth as people because we possess reason and this makes us have infinite worth vs. other things.

Fourth, one can argue that humans are valuable insofar as value-giving is a human act. This is a bit of a variation on Kant's approach that informs the thinking of Hegel and the Kantians (for instance Christine Korsgaard).

One interpretation of Hegel merges the second and the fourth ideas with the notion that we are part of a social command theory. Robert Stern defends this in a book (here's a journal volume on the book).

A fifth view that is that these human lives contribute to a larger organic whole.

This can be expressed somewhat disingenuously as an argument for value is that valuing human life is sociologically or evolutionarily productive. Worded another way, this is the claim that to survive a species or society must do so (with some caveats and qualifications as to what they define as human life, etc. etc). But that's not really an argument for why so much as an explanation that.

The same thing, however, can be taken in a slightly different direction following Aristotle (and Plato and later Hegel) that the organic whole of the society is such that each person is a valuable part. The parts are valued within ethics for the same reason that you care about keeping your legs and hands from damage. An author who writes a lot on this is Martha Nussbaum.

All of this is of course tied up in a question about what "ethics" is and whether we should be moral realists, but on the level of moral arguments for value, these are the ones I can think of.

  • Thanks for recognizing the theological argument +1. I realize that mentioning the other arguments doesn't imply that you adhere to them, but they are, nonetheless, subject to serious objections. For example, couldn't it be argued that death has value because it is in greater harmony with the chaos of entropy, and that any disruption to the homogeneity of chaos (such as human reason) should be the object of disparagement? Why should we value anything that seems so unnatural and improbable as life?
    – user3017
    Commented Oct 19, 2017 at 13:25
  • I'd never thought of that, but I think that is one potential angle. If we take harmony or order to be a value, then lives are valuable insofar as they avoid harmony / disorder. I guess I've never seen that in the literature.
    – virmaior
    Commented Oct 19, 2017 at 23:40
  • The point is that it's completely arbitrary to claim that order, productivity or some sort of organic wholesomeness serve as a norm. Any norm in its capacity to stand against the tide of the natural flow must be qualified in some substantial way. Evolution's assertion that it was all just a convenient accident doesn't even come close.
    – user3017
    Commented Oct 20, 2017 at 1:19
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    The evolution angle strikes me as missing the point in that it does not explain why something has value; only why valuing certain things is advantageous to survival. To give an analogy, cultures that believe 2+2 = 4 probably do outlast ones that don't, but that's not the same thing as saying 2+2 = 4 is true.
    – virmaior
    Commented Oct 20, 2017 at 1:52
  • Good point. The theory of evolution is a blunt instrument that doesn't create anything; it only pummels to death anything that's unfit. So, any evolutionary doctrine of ethics would have to claim that the information content of value judgements simply happened on its own as a convenient accident, having a highly suspect truth value as a result of — what else could it be? — an accident.
    – user3017
    Commented Oct 20, 2017 at 9:57

This question has some similarities with another about absolute truth on this forum. The answer is similar:

We value biological life because our essential goal is to exist. Biological life is valuable because it increases our probabilities of survival. A healthy ecosystem represents more probabilities for our group survival.

There is a human problem in relation to this issue, though. For an group to survive on a system, it is required that the priority is on the system first, and then on the individuals. 200 years ago, humans were a priority over animals and plants, due to sickness had the potential to eliminate huge groups in months. In consequence, human life has been prioritised over animals and plants.

But today, animals and plants are in risk, while our law prioritises humans. If we have to choose between an elephant and a human being, we kill the elephant, and that could be a fallacy, due to it reduces our probabilities of persistence of the planet and therefore of us. Perhaps some day we will prioritise the environment over individuals. And that will not be a devaluation of human life, but precisely the opposite. Preventing human overpopulation would be the factual expression of human value.

  • This is one type of answer -- what we might call a functionalist approach to valuing life...
    – virmaior
    Commented Oct 19, 2017 at 6:36
  • But where does the goal come from? A rock doesn't slide down a hill because of an essential goal to be at the bottom, nor does the theory of evolution suggest that survival is explained because it satisfies a goal. The idea of having a goal presupposes that the goal has value, so your argument is circular. It might be reworded as: "We value biological life because we essentially value existence."
    – user3017
    Commented Oct 19, 2017 at 10:07
  • @PédeLeão: Really interested in your perception, because I can't see the circularity. The word "goal" is a linguistic representation of the most probable outcome of a process. So, 1-(start of the argument) our body has a mechanical tendency to survive, 2-we represent that with language by saying "our goal is to survive", 3-(conclusion) we appreciate life.
    – RodolfoAP
    Commented Oct 20, 2017 at 2:24
  • @RodolfoAP. Normally, a goal presupposes value, but, since you insist that in your argument it doesn't, you're introducing a normative element into it at some point — the naturalistic fallacy. Did that occur with that robotic verbal response — "Our goal is to survive"? Maybe not. But, in any case, you conclude with the appreciation of life which clearly must be normative. Where does this value judgement come from, since you claim that you didn't have any values in your premise?
    – user3017
    Commented Oct 20, 2017 at 8:59
  • Perhaps it would be helpful to reflect on what you really mean by the word "value." There is something that we appreciate about it. It is something we are doing, not something a thing has outside of that. There are little people living inside those little lives and they value it. If we did not exist and there wasn't anything else in the universe to appreciate it or have awareness of it, I wouldn't see it [the universe] as fully existing or having value. If someone or something wants it for some reason, it has value. That is the meaning of it. tag on "value..to whom" whenever this comes up. Commented Nov 9, 2017 at 5:24

First, you haven't said what you mean by "valuable". But a reasonable definition is that a thing is valuable if it is valuable to someone, and that a thing X is valuable to me if I am willing to trade something for it, or willing to trade something for some lottery in which X is the only prize.

It is then empirically the case that lives are valuable because, for example, I am willing to pay for safety equipment and medications whose only salient characteristic is that they have some chance of prolonging my life.

  • To be willing to pay for X is to value X, so you're saying that lives are valuable because we value them (i.e. we are "willing to pay for" such and such to prolong life)? How does that answer the question? We value life just because that's what we do?
    – user3017
    Commented Oct 19, 2017 at 16:32
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    @PédeLeão : The OP wrote: the claim that lives actually are valuable is seemingly an unproven premise. The content of my answer is that the premise is proven empircally. If someone posted a question saying The claim that people like ice cream is an unproven premise, I think it would be useful to point out that we observe people choosing to eat ice cream, and this can be taken as strong evidence that they like it. Ditto for life-preserving measures: people choose to undertake them, and from this we can reasonably infer that they value their lives.
    – WillO
    Commented Oct 19, 2017 at 17:39

In the coldest sense, you could assert that life is valuable because of the resources expended to create said life and the potential value of the resources and work created by that life over its lifetime.

If it takes X resources and Y work to produce a life and this life had a potential (Xp+Yp) resources and work that it would produce over its lifetime, the life would be worth X+Y+Xp+Yp.

Arguably, you can only really measure how much value a life had at its end, although due to the ripple-effect of their actions this value will be forever changing.

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    This is actually a good and complete answer from a utilitarian perspective. A human life takes considerable resources to develop and most of these are lost if it is extinguished. For society, a lost life is generally a net loss, and the survival of society is in danger if too many lives (and thus resources) get wasted.
    – Tom
    Commented Oct 5, 2018 at 18:04

First, you don't define "value", so I'll give the definition I'll be using for this answer : "A factor attributed to a being, an object or a service used, when faced with a choice between several options, to determine which one will be favoured."

Now, from my understanding, the question "Why do ethics always consider that lives are valuable ?" (correct me if I didn't understand the question) stems from the question "How does the nature of Humans make them define ethics that always value lives ?". Notice that I don't keep the "why" in the question because it implies that there would be some kind of "purpose", an arbitrary "reason" for this. Which could only come from a dogma that defines an "objective" sense of "value" that would depend on which dogma the individual adheres to. Making the question entirely opinion-based.

My short answer is : Life's most basic mechanism

Life develops by self-replicating and altering its environment to make it more favourable for the next generation. This induces inter-dependencies that lead to the necessity for life to attribute more value to the living than for the non-living. As a living being that would attribute not enough value would be likely to destroy its living environment, on which its survival and that of his offspring depends. Leading eventually to extinction through basic natural selection process.

Now for the details...

Self Value

It's simple to understand why someone will always attribute value to his own life : a species that commits suicide every time it faces a "choice" cannot survive.


As I already said, living organisms (especially complex ones like Humans) rely on others to survive and develop. So, as a basic consequence of natural selection, species that didn't attribute value to what is beneficial to them disappeared. This effect is further increased through Evolution, as it is a huge evolutional advantage.


  • As a species that takes care of its offspring, Humans needed to develop empathy to help project the value attributed to the self onto their children. Species that didn't take care of their offspring (like some fishes, reptiles, etc), often hid or buried their eggs to lessen the chances they had to find them again later and eat them.

  • As social animal, we Humans also developed an even stronger sense of empathy that extended to many individuals.

  • It also extended to domesticated animals (that quickly became a key element to Human development) though it is not clear if it needed any evolution process or if it's just that empathy applies to anything that has a behaviour that resembles our own (you can have empathy for a suffering ant as you can recognize the way they twist their body as pain, you can have empathy for drawings, etc.) which ended up being convenient to tame/breed animals.

Note that, in the same way, we don't know if empathy existed before it was needed to maintain viable relationships as social animals, as it could have been a tool to better understand preys for example. But when it happened is not really relevant to us anyway. But in any case, that could mean that empathy may not necessarily involve attributing more value to the lives of others.

I think this answers the question "How does the nature of Humans make them define ethics that always value lives ?", but now I'll try to answer your original question :


In larger Human groups where a defined society appeared. The relationships between people are a lot more complex, and can be impossible to handle for individuals. Two new concepts appear in the equation : mentalities and dogmas.

  • Mentalities are an organic result of the processes I mentioned earlier (empathy, environmentalism, self-value, ...) but are very hard to define given that every individual of this large group has a different understanding of these depending on his own personal experience.
  • Dogmas are attempts by society to simplify what the mentalities aspire for by defining arbitrary rules that are supposed to establish "objective values". Dogmas make handling interpersonal relationships a lot easier.

Both dogmas and mentalities, as they ultimately come from the same processes that attribute value to lives, have a tendency to keep that principle intact. However, society factors are a double edged sword when it comes to attributing value to lives :

  • Mentalities are not shared by the whole species (unlike empathy, self-value etc.), they are shared only by the group that defines and follows their principles. And the differences between the in-group and the outsiders induces many fallacies that often lead to attributing more value to the lives in the in-group, and less value for the outsiders.
  • Dogmas are monolithic, and have a hard time adapting to the ever-changing mentalities. As a result of the previous point, a rule reducing the value attributed to the lives of outsiders could be set in stone by a dogma. Then, mentalities evolving could lead to people wanting to attribute more value to outsiders, but the dogma will still dictate otherwise.


In my understanding, Ethics are the take of one individual (or maybe a small group) on the mentalities and/or dogmas, and how those should be according to him.

As Ethics come mostly from an individual's perspective, they are more likely to reflect the attribution of value that comes from individuals feelings like empathy, than group biases. Which could explain why Ethics almost always attribute more value to lives, even when they come from a society that doesn't do as much.

In general, Ethics tend to define a higher moral standard than what society would define because it aims to satisfy the ideals of every individual even including outsiders (in general) whereas mentalities and dogmas just aim to satisfy the average of the group.

Which leads to Ethics almost always attributing more value to lives.

  • As I pointed out to Rodolfo, the naturalistic fallacy introduces a normative element into the argument that didn't exist in the premise, so you're not really answering the OP's question unless that's addressed. It's important to distinguish between an automatic instinctual behavior (non-normative) and a value judgement that actually motivates behavior (normative). An non-normative behavior would be void of any emotion and thus completely indifferent to the outcome.
    – user3017
    Commented Oct 22, 2017 at 2:25
  • This is also questionable: "Humans needed to develop empathy to help project the value attributed to the self onto their children." This is obviously normative, but you don't give any reason why that would be necessary when the instinct to survive is supposedly passed on genetically. To be consistent with your premises it should also be completely untinged by emotion.
    – user3017
    Commented Oct 22, 2017 at 2:29
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    My point wasn't that Self-value is passed on to the child through empathy. What I meant is that empathy was a crucial factor in attributing value to the life of the child. I phrased it that way because it is how empathy works : empathy makes you put yourself in the other's stead (project), and as you see "yourself" in the other, you instinctively attribute him value that you also give to you own life. Also, empathy is an emotion... and even if it wasn't, emotions are also most likely a result of natural selection and evolution so I don't see why it would need to be untinged by emotions.
    – Velraen
    Commented Oct 22, 2017 at 22:17
  • Our languages make us use inappropriate words to describe how processes work, and can be misleading. As such, when I use "needed" I don't mean that there is a predefined "goal". I just take the observation that we exist today and therefore that these adaptations were required to lead up to this observation. For example, it's not that Humans already valued children, then evolved empathy to fulfil their "need" to value children : it's just that otherwise, they would most likely have killed or abandoned their offspring, making the "we exist today as social animals" observation impossible.
    – Velraen
    Commented Oct 22, 2017 at 22:36
  • But you're not really giving an answer. You're just assuming it happened: "[They] evolved empathy to fulfill their 'need' to value children." It's kind of like asking someone, "Where'd you get that airplane?" and getting an answer, "Well, I needed it." The problem is that values could have no effect in motivating behavior unless they have information content, and evolution has no means to explain its origin, especially when the behavior which is motivated runs counter to the natural course of things. A reflex doesn't care, but a value judgement strives to reshape the world as it sees fit.
    – user3017
    Commented Oct 23, 2017 at 1:25

This question dismisses intuition as a justification for valuing lives. This is a mistaken assumption, and fails to understand that we have three potential methods of acquiring knowledge, not just two:

  • a) Reasoning from first principles
  • b) Inductive empirical inference
  • c) Direct intuitive knowledge

Our intuitions are often wrong, and our trust in them often misplaced, so what is needed, is a justification for trusting our moral intuitions.

This can be done in two ways. The most straightforward, is to accept the reality of abstract objects, including moral principles. There is a bare majority of philosophers who believe in moral realism, and for anyone who holds such a belief, there is a pretty straightforward Darwinian rationale to accept that we humans have developed a moral intuition to detect such a real phenomenon in the universe. Darwinian processes provide us, ceteris paribus, with an advantage for being able to detect real phenomenon, because then we can use that knowledge in our dealing with that reality.

The ACCURACY of that sense, is highly suspect, because of the demonstrated diversity of our collective moral intuitions. But if one accepts the reality of moral realism, then that our intuitive sensing of morality is inaccurate is only a pragmatic problem, in that we need to figure out how to selectively use and correct these intuitions, not justify them.

For those that do not accept ontic moral realism there is another view that holds that social constructs are "real" in an emergent sense. One approach to this sort of emergent reality was articulated by John Searle, in The Construction of Social Reality. Searle's is not the only way to do this kind of emergent semi-ontology, but it is the most widely discussed and can be used as exemplar. When institutions or communities create social realities, those realities become real, and matter in the world, and can be detectable evolutionarily, just as with abstract realism. Both human centric eusociality, or Gaia-based eusociality, can be assumed to create these sorts of social realities, either applicable just to humans, or to all of life, respectively. The principle of valid but fallible intuitions would then apply again.

The justification of the value of life, then, is thru our moral intuitions, which inform us that life is intrinsically to be valued.

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