Epistemic Status: confused & unlikely

Author's note: the central claim of this article I now believe is confused, and mostly inaccurate. More precisely (in response to a comment by ChristianKl)

>Whose idea of reductionism are you criticising? I think your post could get more useful by being more clear about the idea you want to challenge.

I think this is closest I get to having a "Definiton 3.4.1" in my post

"...the other reductionism I mentioned, the 'big thing = small thing + small thing' one..."

Essentially, the claim is that to accurately explain reality, non-reductionist explanations aren't always *wrong*. 

The confusion, however, that I realized elsewhere in the thread, is that I conflate 'historical explanation' with 'predictive explanation'. Good predictive explanation will almost always be reductionist, because, as it says on the tin, big are made of smaller things. Good historical explanations, though, will be contra-reductionist, they'll explain phenomena in terms of its relation to the environment. Consider evolution; the genes seem to be explained non-reductionistically because their presence or absence is determined by its effect on the environment i.e. whether its fit, so the explanation for how it got there necessarily includes complex things because they cause it.

>Apart from that I don't know what you mean with theory in "Reductionism is a philosophy, not a theory." As a result on using a bunch of terms where I don't know exactly what you mean it's hard to follow your argument.

Artifact of confusion;  if contra-reductionism is a valid platform for explanation, then the value of reductionism isn't constative -- that is, it isn't about whether it's true or false, but something at the meta-level, rather than the object level. The antecedent is no longer believed, so now I do not believe the consequent.

The conceit I had by calling it a philosophy, or more accurately, a perspective, is essentially that you have a dataset, then you can apply a 'reductionist' filter on it to get reductionist explanations and a 'contra-reductionist' filter to get contra explanations. This was a confusion; and only seemed reasonable because I I was treating the two type of explanation -- historical and predictive -- as somehow equivalent, which I now know to be mistaken.

Reductionism is usually thought of as the assertion that the sum of the parts equal the whole. Or, a bit more polemically, that reductionist explanations more meaningful, proper, or [insert descriptor laced with postive affect]. It's certainly appealing, you could even say it seems reality prefers these types of explanation. The facts of biology can be attributed to the effects of chemistry, the reactions of chemistry can be attributed to the interplay of atoms, and so on.

But this is conflating what is seen with the perspective itself; I see a jelly donut therefore I am a jelly donut is not a valid inference. Reductionism is a way of thinking about facts, but it is not the facts themselves. Reductionism is a philosophy, not a theory. The closest thing to an testable prediction it makes it what could be termed an anti-prediction.

Another confusion concerns the alternatives to reductionism. The salient instance of anti-reduction tends to be some holist quantum spirituality woo, but I contend this is more of a weak man than anything. To alleviate any confusion, I'll just refer to my proposed notion as 'contra-reductionism'.

Earlier, I mentioned reductionism makes no meaningful predictions. To clarify this, I'll distinguish from a kind a diminutive motte of reductionism which may or may not actually exist outside my own mind, (and which truly is just a species of causality, broadly construed). In broad strokes, this reductionism 'reduces' a phenomena to the sum of it's causes, as opposed to its parts. This is the kind of reductionist explanation that treats evolution as a reductionist explanation, indeed it treats almost any model which isn't strictly random as 'reductionist'. The other referent would be reductionism as the belief that "big things are made of a smaller things, and complex things are made of simpler things". 

It's is the former kind of reductionism that makes what I labeled an anti-prediction, the core of this argument is simply that reductionist is about causality; specifically, it qualifies what types of causes should even be considered meaningful or well-founded or simply, worth thinking about. If you broaden the net sufficiently, causality is a concept which even makes sense to apply to mathematical abstraction completely unrooted in any kind of time. That is the interventionist account of causality essentially boils it down to 'what levers could we have pulled to make something not happen', which perfectly translates to maths, see, for instance, reductio ad absurdum arguments.

But I digress. This diminutive reductionism here is simply the belief that things can be reduced to their causes, which is on par with defining transhumanism as 'simplified humanism' in the category of useless philosophical mottes. In short, this is quite literally an assertion of no substance, and isn't even worth giving a name.

Now that I've finished attacking straw men, the other reductionism I mentioned, the 'big thing = small thing + small thing' one, is also flawed, albeit useful nonetheless.

This can be illustrated by the example of evolution I mentioned: An evolutionary explanation is actually anti-reductionist; it explains the placement of nucleotides in terms of mathematics like inclusive genetic fitness and complexities like population ecology. Put bluntly, the there is little object-level difference between explaining genes sequences with evolution and explaining weather with pantheons of gods (there is meta-level difference; i.e. one is accurate). Put less controversially, this is explicitly non-reductionistic; relatively simple things (the genetic sequence of a creature) are explained in the language of things far more complex (population and environment dynamics over the course of billions of years). If this is your reductionism, all it does is encapsulate the ontology of universe-space, or more evocatively, it's a logic that doesn't -- couldn't -- tell you where you live, because doesn't change wherever you may go.

Another situation where reductionism  and contra-reductionism give different answers is an example cribbed from David Deutsch. It's possible to set up dominos so that they compute an algorithm which decides the primality of 631. How would you explain a a positive result?

The reductionist explanation is approximately: "the domino remains standing because the one behind it didn't fall over", and so on with variation such as "that domino didn't fall over because the one behind it was knockovered sideways". The contra-reductionist explanation is "that domino didn't fall over "because 631 is prime". Each one is 'useful' depending on whether you are concerned with the mechanics of the domino computer or the theory.

You might detect something in these passages -- that while I slough off any pretense of reductionism, glorious (philosophical) materialism remains a kind of true north in my analysis. This is my thesis. My contra-reductionism isn't non-materialistic, it's merely a perspective inversion of the sort highlighted by a figure/ground illusion. Reductionism defines -- reduces -- objects by pointing to their constituents. A mechanism functions because its components function. A big thing of small things. Quasi-reductionism  does the opposite, it defined objects by their impact on other objects, "[A] tree is only a tree in the shade it gives to the ground below, to the relationship of wind to branch and air to leaf." I don't mean this in a spiritual way, naturally (no pun intended). I am merely defining objects externally rather than internally. At the core, the rose is still a rose, the sum is still normality.

If I had to give a short, pithy summation of this post, the core is simply that, like all systematized notions of truth or meaningfulness, reductionism collapses in degenerate cases where it fails to be useful or give the right answer. Contra-reductionism isn't a improvement or a replacement, but a alternative formulation in a conceptual monoculture, which happens to give right answer sometimes.