I did not say that non-reductionism is absurd. I said that "recognizing the absurdity of all other proposed hypotheses is another way of coming about the correct beliefs".

Nonetheless, I do think that non-reductionism is absurd. I cannot imagine a universe which is not reductionistic.

Can you explain to me how it might work?

One formulation of reductionism is that natural laws can be ordered in a hierarchy, with the higher-level laws being predictable from, or reducible to, the lower ones. So emergentism, in the cognate sense, not working would be that stack of laws failing to collapse down to the lowest level.

Who are to enact that the laws governing the behavior of particles are more ultimate than the transcendent, emergent laws of the collective they generate, such as the principles of organization responsible for emergent behavior? According to the physicist George F. R. Ellis true complexity emerges as higher levels of order from, but to a large degree independent of, the underlying low-level physics. Order implies higher-level systemic organization that has real top-down effects on the behavior of the parts at the lower level. Organized matter has unique properties (Ellis 2004).

There's two claims there: one contentious, one not. That there are multiply-realisable, substrate-independent higher-level laws is not contentious. For instance, wave equations have the same form for water waves, sound waves and so on. The contentious claim is that this is ipso facto top-down causation. Substrate-independent laws are still reducible to substrates, because they are predictable from the behaviour of their substrates.

And even after the answer of "Why? Emergence!" is given, the phenomenon is still a mystery and possesses the same sacred impenetrability it had at the start.

I don't see how that refutes the above at all. For one thing, Laughlin and Ellis do have detailed examples of emergent laws (in their rather weak sense of "emergent"). For another, they are not calling on emergence itself as doing any explaining. "Emergence isn't explanatory" doesn't refute "emergence is true". For a third, I don't see any absurdity here. I see a one-word-must-have-one-meaning assumption that is clouding the issue. But where a problem is so fuzzilly defined that it is hard even to identify the "sides", then one can't say that one side is "absurd".

Every time he makes the specific claim that reductionism makes worse predictions than a belief in "emergent phenomenon" in which "organizational structure" is an additional property that all of reality must have, in addition to "mass" and "velocity", he cites himself for this.

Neither are supposed to make predictions. Each can be considered a methodology for finding laws, and it is the laws that do the predicting. Each can also be seen as a meta-level summary fo the laws so far found.

He also does not provide any evidence for non-reductionism over reductionism; that is, he cannot name a single prediction where non-reductionism was right, and reductionism was wrong.

EY can't do that for MWI either. Maybe it isn't all about prediction.

A good example, he says, is genetic code: to assume that dna is actually a complete algorithmic description of how to build a human body is an illogical conclusion, according to him.

That's robustly true. Genetic code has to be interpreted by a cellular environment. There are no self-decoding codes.

He would rather suppose that the universe contains rules like "When a wavefunction contains these particular factorizations which happen not to cancel out, in a certain organizational structure, use a different mechanism to decide possible outcomes instead of the normal mechanism" than suppose that the laws of physics are consistent throughout and contain no such special cases. From the standpoint of simplicity, reductionism is simpler than non-reductionism, since non-reductionism is the same thing as reductionism except with the addition of special cases.

Reudctionism is an approach that can succeed or fail. It isn't true apriori. If reductionism failed, would you say that we should not even contemplate non-reductionism? Isn't that a bit like eEinstein's stubborn opposition to QM?

He specifically objects that reductionism isn't always the "most complete" description

I suppose you mean that the reductionistic explanation isn't always the most complete explanation...well everything exists in a context.

of a given phenomenon; that elements of a given phenomenon "cannot be explained" by looking at the underlying mechanism of that phenomenon.

There is no apriori guarantee that such an explanation will be complete.

I think this is nonsense. Even supposing that the laws of physics contain special cases for things like creating a human body out of DNA, or for things like consciousness,

That isn't the emergentist claim at all.

then in order for such special case exceptions to actually be implemented by the universe, they must be described in terms of the bottom-most level.

Why? Because you described them as "laws of physics"? An emergentist wouldn't. Your objections seem to assume that some kind of reductionism+determinism combination is true ITFP. That's just gainsaying the emergentist claim.

Even if a DNA strand is not enough information to create a human being, and the actual program which creates the human being is hard coded into the universe, the object that the program must manipulate is still the most basic element of reality, the wavefunction, and therefore the program must specify how certain amplitude configurations must evolve, and therefore the program must describe reality on the level of quarks.

If there is top-down causation, then its laws must be couched in terms of lower-level AND higher-level properties. And are therefore not reductionistic. You seem to be tacitly assuming that there are no higher-level properties.

his is still reductionism, it is just reductionism with the assumed belief that the laws of physics were designed such that certain low-level effects would take place if certain high-level patterns came about in the wavefunction.

Cross-level laws aren't "laws of physics". Emergentists may need to assume that microphysical laws have "elbow room", in order to avoid overdetermination, but that isn't obviously wrong or absurd.

At first when I read EY's "The Futility of Emergence" article, I didn't understand. It seemed to me that there's no way people actually think of "emergence" as being a scientific explanation for how a phenomenon occurs

As it happens, no-one does. That objections was made in the most upvoted response to his article.

such that you could not predict that the phenomenon would occur if you know how every piece of the system worked individually.

Can you predict qualia from brain-states?

I didn't think it possible that anyone would actually think that knowing how all of the gears in a clock work doesn't mean you'll be able to predict what the clock will say based on the positions of the gears (for sufficiently "complex" clocks).

Mechanisms have to break down into their components because they are built up from components. And emergentists would insist that that does not generalise.

But perhaps he read this very paper, because Laughlin uses the word "emergent phenomenon" to describe behavior he doesn't understand, as if that's an explanation for the phenomenon.

Or as a hint about how to go about understanding them.

He does not explore the logical implications of this belief: that holding the belief that some aspects of a phenomenon have no causal mechanism,

That's not what E-ism says at all.

and therefore could not have possibly been predicted. He makes the claim that a hypothetical Theory of Everything would not be able to explain some of the things we find interesting about some phenomenon. Does he believe that if we programmed a physics simulator with the Correct Theory of Everything, and fed it the boundary conditions of the universe, then that simulated universe would not look exactly like our universe?

That's an outcome you would get with common or garden indeterminism. Again: reductionism is NOT determinism.

That the first time DNA occurred on earth, in that simulated universe, it would not be able to create life (unlike in our universe) because we didn't include in the laws of physics a special clause saying that when you have DNA, interpret it and then tell the quarks to move differently from how they would have?

What's supposed to be absurd there? Top-down causation, or top-down causation that only applies to DNA?

I read the whole paper by Laughlin and I was unimpressed.

The arguments for emergence tend not be good. Neither are the arguments against. A dippsute about a poorly-defined distinction wit poor arguments on both sides isn't a dispute where one side is "absurd".