Shiluach Haken, Part One: Save the Pigeons?

What is the rationale behind the mitzvah of shiluach haken, sending away the mother bird?

The Rambam, in "Guide for the Perplexed", explains that we are enjoined to send away the mother bird as an act of compassion, to spare her the anguish of seeing her children taken away for the slaughter.

This approach strikes me as very strange.  Is sending away the mother bird really an act of compassion?  Does the bird really experience less anguish when she is sent away than when her children are taken before her eyes?  Clearly, she is trying to protect her children -- why does it matter whether you send her away or whether you take the children?

The Ramban, in his commentary on the Torah, gives a different explanation.  He says that by sending away the mother bird, we are saving the species, even as we are consuming the individuals.

So according to the Ramban, “send away the mother bird” should be understood as “spare the mother bird”.  When you find a bird’s nest inhabited by a mother and children, don’t eat all the birds; eat the children, and leave the mother alone.

I like the Ramban’s approach, but I don’t think it should be understood as the expression of a “caretaker” environmentalism, which would enjoin us to protect endangered species for the sake of biodiversity.  I think that the reason we are supposed to protect “species” (really, populations) of kosher birds is so that we will be able to go on eating the individuals.  We are supposed to send away the mother bird so that she can make more baby birds for us to eat.  It’s sustainable hunting, essentially.

Similarly, the original mitzva of "bal tashchit" prohibits cutting down trees under some circumstances, but the prohibition explicitly applies only to trees with human-edible fruit. The Torah is not concerned with botanical diversity, but with sustainable consumption of natural resources. (Thanks to my father for pointing this out!)

The sabbatical year may also be related in part to sustainable farming. The sabbatical year demonstrates the Divine ownership of the land, but it also allows the land to "rest".

Don't get me wrong, though. I don’t mean to say that the Torah is indifferent to the suffering of animals.  The Torah clearly cares about animal suffering.  That consideration has its own dedicated mitzva, “tzaar baalei chayim”, the prohibition of causing needless suffering to animals.  But shiluach haken is not about compassion.  It’s about the tragedy of the commons.

For a more thorough treatment of the intellectual history of shiluach haken, please see the wonderful paper by Rabbi Natan Slifkin, available here: http://www.rationalistjudaism.com/2010/08/shiluach-hakein-transformation-of.html

Empricism with a Formalist Face: A Platonic Dialogue by MC Complete

Stewart: Enough of epistemology.  Let’s get down to brass tacks.  What is a number?

Daniel: A number is the outcome of a measurement.  Take the expression “7 + 5 = 12”.  This expression is an empirical prediction (or, if you are a hard core skeptic, an empirical generalization).  I could test it by putting seven apples and five oranges in a basket and counting them.  Counting is an empirical process that yields the result, 12.  The assumption that I started with -- that there are seven apples and five oranges -- means that when I count the apples I get 7, and when I count the oranges I get 5.

Stewart: Hmmm.  Interesting, but doesn’t that just beg the question?  You said “I get 12” -- but what *is* 12?  What do you get?

Daniel: 12 has a written form and an auditory signature, which vary, of course, according to language.  It’s a linguistic token.

Stewart: But that’s formalism.  I thought that you were an empiricist regarding math.

Daniel: It’s formalism with an empiricist heart, or maybe empiricism with a formalist face.  Numbers are linguistic tokens that are the return value of an empirical procedure.  Linguistic tokens are sense data, among other things.

Stewart: Interesting that you drew on deductivism in your last post, which is a branch of formalism.  I see how you’re advocating a compromise position between formalism and empiricism.

Daniel: Compromise?  I prefer to call it The Great Synthesis.

The Empiricist Strikes Back: A Platonic Dialogue by MC Complete

Daniel: Don’t get me wrong, Stewart, I’m not a hard core empiricist.  But they empiricists were right about some things.

Stewart: What do you have in mind?

Daniel: Math, for example.

Stewart: Really?  You think math is the crown jewel of empricism?  Very well then, I’ll play your game.  Tell me, Daniel, what are we to make of the Euclidean postulate that between any two points one can draw a straight line?

Daniel: What’s the problem?  Take out a sheet of paper and a pencil, make two dots anywhere, then connect them.  Bang!  Straight line.

Stewart:  But it’s not a breadthless line.

Daniel: Breadthless?  Who said anything about breadthless?

Stewart: John Stuart Mill.  He said that lines are “limit concepts”.

Daniel: Yeah, that whole “limit concepts” strategy was a big mistake.  Lines aren’t limit concepts.  They’re just very thin.

Stewart: And what about the postulate that all lines can be bisected by a perpendicular line?

Daniel: That’s empirical too -- as long as you interpret it correctly.  What it really means is that all sufficiently long lines can be bisected that way.  Between you and me, if a line is really too short to be bisected, it’s not much of a line, is it?  It’s more of a dot, wouldn’t you say?

Stewart: And what about heartbeats?  How can you empirically justify the proposition that 2 heartbeats plus 3 heartbeats equals 5 heartbeats?

Daniel: That’s easy.  Take an MP3 file with 5 heartbeats.  I can play that file and count 1, 2, 3, 4, 5 -- and then I can play the file again and count 1, 2, 1, 2, 3.

Stewart: And what is 500 red marbles plus 500 blue marbles?

Daniel: Oh, about 1000 marbles, I’d say.

Stewart: “About” 1000?  You seem to have anticipated my line of argument.

Daniel: You were going to say that if I counted the marbles, I probably wouldn’t come up with exactly 1000.

Stewart: Yes, that’s exactly what I was going to say.  How did you know?

Daniel: First of all, I read your book.  Second of all, I’m the one writing the dialogue.  Anyway, here’s my point.  Arithmetic with big numbers, like geometry and arithmetic with continuous quantities, is only approximate.  I mean you have to reinterpret the propositions to be approximate propositions.  So we usually say 500 + 500 = 1000, but what we really mean is 500 + 500 is about equal to 1000.

Stewart: And what about infinity?

Daniel: Infinity?  What’s the big deal with infinity?

Stewart: Well, imagine a universe with only 100 objects.

Daniel: OK.

Stewart: In such a universe, is the proposition “75 * 2 = 150” true or false?

Daniel: Good question.  First of all, let’s agree that the proposition “75 * 2 = 150” is the outcome of applying the arithmetic algorithms.

Stewart: OK.

Daniel: And the arithmetic algorithms themselves work in the Hundredverse -- for all actual quantities that we can test.

Stewart: OK.

Daniel: So the expression “75 * 2 = 150” is kind of an “if then” statement -- it means that if we had a set of 75 objects that we could double, we’d expect the result to be 150.  Since there is no such set in the Hundredverse, the “if” part is not satisfiable.

Stewart: That sounds kind of like deductivism.

Daniel: I think it is a kind of deductivism, but traditional deductivism is agnostic about the justification for the axioms.  I think the justification is empirical.

Stewart: And what is that justification?  Enumerative induction?  The web of knowledge?

Daniel: Neither.  The justification for math is more or less the same as the justification for physics: experiment.

Stewart: But mathematicians don’t do experiments.

Daniel: They don’t need to.  The physicists do the experiments for them.  In order to predict the outcome of a physics experiment you need physics *and* math -- so the success of the experiment justifies both kinds of inputs.

Stewart: And what about mathematical induction?  And the completeness axiom?

Daniel: I’m not smart enough to know if these mathematical tools are used in physics or not, but I would have to go with Quine here.  If they are used in physics, they are justified by the experiments that test them.  If not, they are toys and curiosities.  Of course, sometimes a caterpillar of pleasure can become a butterfly of knowledge.  This happens in physics too, for example in the case of relativity.

Stewart: And you would also go with Quine in rejecting the certainty and necessity of mathematics?

Daniel: Yes.  As you say in your account of Quineinism, “We cannot conceve of 7 + 5 being anything other than 12.  This, however, is a psychological feature of human beings”.