According to some ethical theories that make happiness the central touchstone of morality, for instance utilitarianism, human happiness should not count more strongly than happiness in the non-human animal world. One quantum (as it were) of human happiness should contribute as much to the grand calculus of pleasure as does one quantum of rat happiness. Now, it may be that humans are capable of more happiness than rats; or perhaps, as John Stuart Mill argued in his Utilitarianism, they are capable of a kind of happiness that is of greater value than any happiness a rat could experience. But that's not to privilege humans; it's just to acknowledge a fact about their greater capacity for happiness.

You wonder whether this might be unfair, because you wonder whether, if an elephant had written Utilitarianism, the theory would have looked a bit different (say, assigning great value to distinctively elephantine pleasures). But this is an impossible road. We are human, we are who we are, and we have no choice but to think our thoughts and come to our conclusions. Of course, empathy with other creatures is an important part of our moral reflection. But still, it is we who must do the empathizing. At the end of the day, there is nothing for it but to come to our conclusions about what's right. There is such a thing as thinking "out of the box" -- but we can't get so far out of the box that we leave ourselves behind.

I appreciate that your question actually asks not about happiness but life. Now, if it's wrong to take a life because it deprives someone or some thing of future happiness, then perhaps the above remarks are still of relevance. But if taking a life is wrong for other reasons, for reasons unconnected to happiness, then the explanation about why human life is more valuable than non-human life (if indeed it is) will have to look quite different.

Installment 1: I beg your indulgence. Please be patient while I prepare a satisfactory answer to this tough question. In the meantime, read something I posted in reply to another question in this category:

In Harry Frankfurt's account of love, there are four "conceptually necessary features" (The Reasons of Love, pp. 79-80). First, love is "disinterested concern for the well-being or flourishing of the person who is loved." "Disinterested" means "unmotivated by any instrumental concern." Second, love is "ineluctably personal," that is, "[t]he person who is loved is loved for himself or for himself as such, and not as an instance of a type" (Reasons, pp. 79-80; see p. 44). Third, the lover "identifies with his beloved." And fourth, love "is not a matter of choice but is determined by conditions that are outside our immediate voluntary control" (Reasons, p. 80; see p. 44).

Installment 2 (I'm going to add a little at a time, so stayed tuned, and come back): Henceforth I will speak, in installment 3 and beyond, about the properties of love, and try to list them. Maybe, though, we can define love, but not by listing its features. What is the alternative to defining something by listing its features? How about a pointing? --whereby I define love ostensively. Raymond Romano gives his twin babies a bath in the kitchen sink, then carefully dries them off, all the time soothing them with his words and touches. I point to the scene on the TV screen and say, "there's love!" Or two old polar bears snuggle on an ice cap, and I point to them, exclaiming, "Now, that's love." What I did, does it count as defining love without providing a list of its features? The ostensive definition might be a bad one ("what are you pointing at, Soble?") , but that seems beside the point. Maybe, though, the alternative to providing a list of features is to sing a song, or play a tune on the violin, or write a poem, or dance across the flower fields, or throw some acrylics on canvas, thereby defining love (impressionistically?) without listing its features.

Installment 3: Let's assume that there are two kinds of properties, characteristics, or features a thing can have: necessary (constitutive; definitive) features and accidental (contingent) features. A necessary feature is a feature such that if a thing lost it, it would no longer be the kind of thing it had been; or if a thing never did have it, it would not be a thing of the kind you had in mind. An accidental feature is a feature such that if a thing lost it, it could still be the kind of thing it had been; or if a thing never had it, it could still be the kind of thing you had in mind. Example: a necessary feature of a (normal) bird is that it be able to fly; whether a bird flies slowly or quickly is not a necessary feature of a bird, but contingent on many factors. Necessary features of an internal combustion automobile are its having spark plugs and cylinders, etc.; the color of any particular car is a contingent feature of that car. Then the question is: are we able to state or list the necessary features of love. Or of, say, sexual desire (to take a related notion). Frankfurt (see above) thinks he has identified four necessary features of love, such that if any phenomenon lacked any one of those features, it would not be love, but something else. It is difficult business stating the necessary conditions of anything, let alone love. Further, even if we find some or all of the necessary features of something, that does not provide us with a list of sufficient features--features that guarantee that something is what it is or make something what it is. Note that Frankfurt lists only four necessary conditions of love, and he never claims that they are jointly sufficient. What this means is that even though the absence of one feature entails that the phenomenon is not love, the presence of all four does not guarantee that the item is love. Providing both necessary and sufficient conditions for anything is challenging (that is an understatement). In future installments we shall take a look at some attempts. For now, try to think of counterexamples to Frankfurt's account of love: cases of love that do not exhibit at least one of his four necessary features.

I now realize that I have begun to write a book on love. This could go on forever. In installments 4 and 5 I reproduce part of what I wrote in other installments. Is the question-poser still with us? More to come....

Installment 4: It seems to be true that loving a person (or even an animal) and loving an object or thing (chocolate, or a feeling) are different. If both these two phenomena are in fact types of love, what do they have in common in virtue of which they are love? A tough one. Alternatively, we could say that "love" for a thing is not love at all, but something else; it has some things but not much of anything else in common with love for a person. It was Aristotle who claimed that we could not love (philia) wine, or be its real friend, both because the wine cannot reciprocate and because we cannot wish the wine well for its own sake (but only for ours). Still again, we could resort to a "family resemblance" account of love, in which case there may not be any interesting common feature that links all loves together, and we can meaningfully speak both of loving a person and loving a thing or a feeling. We do so all the time in English, at least ("I just love your shoes!"), so Ordinary Language is on the side of both these phenomena being genuine cases of love. Or, because other languages are more linguistically sophisticated, what OL-English implies is that Americans (and the British? who else?) have a screw loose about love.

Installment 5 (approaching a necessary feature of love?): Suppose X and Y love each other, and that X wonders whether X may leave Y, despite their mutual love, when doing so will cause Y (and presumably X, too) anguish. Or is there an obligation to remain together? And if there is an obligation to stay, is it an obligation that flows from the love itself or from general moral principles? Philosophers have debated the relationship betweeen love and morality. One case goes like this: I love my wife. She is drowning. But in a different direction ten people are drowning. I can save my wife or the ten, but not both. What should I do? Consequentialist ethics might say: save the ten, jettison your wife, because 10 is greater than one, and your preference for your wife, and hers for you, don't count enough. Or a different consequentialist (a rule-consequentialist) might say: save your wife; things go much better overall if we save those with whom we are that close, and they can count on our doing so. Deontology might say: ethics itself obligates you to save your beloved wife, even if the number of persons lost in the other direction were 1000 and not merely 10. Some philosophers think that this dispute is irrelevant, for love by itself, independently of ethics, creates obligations. So there can be obligations generated by moral concerns, and obligations generated by love concerns. Then in the drowning case, the question is not, what does ethics tells us about whom to save, but rather: which is more important, the ethical obligation or the love obligation? Or are they incommensurable, and we cannot ask which is more important?

However, I am attracted to a different approach. Some philosphers would say that if we stop for even one nanosecond, and ask either (1) what does ethics tell us about whom to save or (2) which type of obligation--ethics or love--trumps the other, we have missed the Whole Point. For if X really does love Y, X will, without delay and any deliberation, jump into the water and head toward Y, his beloved wife. Not doing so is neither morally a failure toward the wife nor morally proper toward the ten saved; and not doing so does not violate the obligations of love. Instead, not doing so negates the claim that X loves Y in the first place. If so, we have a necessary feature of love: that X would save Y automatically, without thinking, even if X realizes that 1000 others will die as he/she rescues his/her beloved. Too romantic?

Installment 6: If you didn't like Frankfurt's list, try W. Newton-Smith's (from his essay in my collection Eros, Agape, and Philia). I reproduce it (what follows are his Love Comprising Relations, LCRs):

1. A knows B (or at least knows something of B)

2. A cares (is concerned) about B

A likes B

3. A respects B

A is attracted to B

A feels affection for B

4. A is committed to B

A wishes to see B's welfare promoted.

My comments:

(i) note the absence of A sexually desires B; (ii) Newton-Smith says that the LCRs are not merely evidence for love but the components of love; (iii) he also says that not all are necessary, in the sense that some might be missing yet A still loves B -- love "involves the satisfaction of the LCRs to an . . . unspecified degree"; (iv) love, for WNS, includes beliefs, desires, and affects; (v) several items on his list seem to be redundant; (vi) he does not explain why he groups together various disparate items. I am no more happy with WNS's list than I am with Frankfurt's.

What a relief! Others have decided to add to this thread. The search for the fine gold thread of love -- the property "common to" and possessed by all types or forms of love -- has gone on for centuries. Another problem with Gert's succinct account is that it doesn't apply to our love for things, but only for persons (and perhaps animals: Equus). Hence either he hasn't uncovered the fine gold thread of all loves, but only of a subset; or if he has uncovered the fine gold thread of all loves, our "loves" for things are, after all, not really loves. Robert Nozick has proposed, "What is common to all love is this: your own well-being is tied up with that of someone (or something) you love" ("Love's Bond"). Does Nozick's fine gold thread distinguish love from both lust and liking? Does it "account for all of the [other] characteristics of love," whatever they happen to be? (Wasn't that our question?) Regardless, note that Nozick thinks that the fine gold thread of love also applies to our love for things. Could it be that my own well-being is tied up with, say, an automobile? Stranger things have happened in the universe of love. Many philosophers (from Plato to Tillich) have supposed, instead, that what is common to all love is a desire to form a union with the loved person or object. I once argued that the desire for union is the central ingredient of romantic love, and could explain all the other features of romantic love. But these philosophers go farther, claiming that the desire to merge with the other person or thing (or with God) is the mark of all types of love, including, say, my loving chocolate ice cream. I can merge with it by eating it, but I cannot take pleasure in its pleasure. Which reminds me that Aristotle might side with Gert here, if he wants to exclude things as proper objects of love. Another possibility is that in all types of love the lover is concerned for the well-being or flourishing of the person or thing loved (see Newton-Smith). Aristotle is relevant here, too, since we cannot wish wine well for its own sake. Further, there are tangles (perhaps, however, not insuperable) in thinking of the human love for God as a case of being concerned for the well-being of the beloved.